@article {2363, title = {Selective C-H Activation alpha to Primary Amines. Bridging Metallaaziridines for Catalytic, Intramolecular alpha-Alkylation}, journal = {Journal of the American Chemical Society}, volume = {131}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 427PWTimes Cited: 22Cited Reference Count: 28Bexrud, Jason A. Eisenberger, Patrick Leitch, David C. Payne, Philippa R. Schafer, Laurel L.}, month = {Feb}, pages = {2116-+}, type = {Article}, abstract = {Selective alpha-C-H activation results in the synthesis of the first bridging metallaaziridine complex for the catalytic alpha-alkylation of primary amines. Reaction development led to the preparation of new Zr 2-pyridonate complexes for this useful transformation. No nitrogen protecting groups are required for this reaction, which is capable of assembling quaternary chiral centers a to nitrogen. Preliminary mechanistic investigations suggest bridging metallaaziridine species are the catalytically active intermediates for this alpha-functionalization reaction, while monomeric imido complexes furnish azepane hydroamination products.}, keywords = {ALKENES, ALKYNES, BOND ACTIVATION, COMPLEXES, GENERATION, HYDROAMINOALKYLATION, INTERMOLECULAR HYDROAMINATION, NITROGEN, REACTIVITY, UNACTIVATED OLEFINS}, isbn = {0002-7863}, url = {://000264792200038}, author = {Bexrud, J. A. and Eisenberger, P. and Leitch, D. C. and Payne, P. R. and Schafer, L. L.} } @article {23411, title = {Side-on End-on Bound Dinitrogen: An Activated Bonding Mode That Facilitates Functionalizing Molecular Nitrogen}, journal = {Accounts of Chemical Research}, volume = {42}, year = {2009}, month = {Jan}, pages = {127-133}, type = {Review}, abstract = {

Molecular nitrogen is the source of all of the nitrogen necessary to sustain life on this planet. How it is incorporated into the biosphere is complicated by its intrinsic inertness. For example, biological nitrogen fixation takes N-2 and converts it into ammonia using various nitrogenase enzymes, whereas industrial nitrogen fixation converts N-2 and H-2 to NH3 using heterogeneous iron or ruthenium surfaces. In both cases, the processes are energy-intensive. Is it possible to discover a homogeneous catalyst that can convert molecular nitrogen into higher-value organonitrogen compounds using a less energy-intensive pathway? If this could be achieved, it would be considered a major breakthrough in this area. In contrast to carbon monoxide, which is reactive and an important feedstock in many homogeneous catalytic reactions, the ischelectronic but inert N-2 molecule is a very poor ligand and not a common industrial feedstock, except for the above-mentioned industrial production of NH3. Because N-2 is readily available from the atmosphere and because nitrogen is an essential element for the biosphere, attempts to discover new processes involving this simple small molecule have occupied chemists for over a century. Since the first discovery of a dinitrogen complex in 1965, inorganic chemists have been key players in this area and have contributed much fundamental knowledge on structures, binding modes, and reactivity patterns. For the most part, the synthesis of dinitrogen complexes relies on the use of reducing agents to generate an electron-rich intermediate that can interact with this rather inert molecule. In this Account, a facile reaction of dinitrogen with a ditantalum tetrahydride species to generate the unusual side-on end-on bound N-2 moiety is described. This particular process is one of a growing number of new, milder ways to generate dinitrogen complexes. Furthermore, the resulting dinitrogen complex undergoes a number of reactions that expand the known patterns of reactivity for coordinated N-2. This Account reviews the reactions of ([NPN]Ta)(2)(mu-H)(2)(mu-eta(1):eta(2)-N-2), 2 (where NPN = PhP(CH2SiMe2NPh)(2)), with a variety of simple hydride reagents, E-H (where E-H = R2BH, R2AlH, RSiH3, and Cp2ZrCl(H)), each of which results in the cleavage of the N-N bond to form various functionalized imide and nitride moieties. This work is described in the context of a possible catalytic cycle that in principle could generate higher-value nitrogen-containing materials and regenerate the starting ditantalum tetrahydride. How this fails for each particular reagent is discussed and evaluated.

}, keywords = {ammonia, CLEAVAGE, CONVERSION, COORDINATED N-2 LIGAND, H-2, HYDROSILYLATION, MOLYBDENUM, REACTIVITY, REDUCTION, TANTALUM COMPLEX}, isbn = {0001-4842}, author = {Fryzuk, MD} } @article {2592, title = {Toward Alkane Functionalization Effected with Cp*W(NO)(alkyl)(eta(3-)allyl) Complexes}, journal = {Organometallics}, volume = {28}, number = {15}, year = {2009}, note = {ISI Document Delivery No.: 476PYTimes Cited: 2Cited Reference Count: 32Semproni, Scott P. Graham, Peter M. Buschhaus, Miriam S. A. Patrick, Brian O. Legzdins, Peter}, month = {Aug}, pages = {4480-4490}, type = {Article}, abstract = {Cp*W(NO)(n-alkyl)(eta(3)-allyl) complexes result from the selective activations of the terminal C-H bonds of alkanes. Consequently, the reactions of prototypical members of this family of complexes with a range of electrophilers and nucleophiles have been explored with a view to developing methods for functionalizing the newly formed alkyl ligands. The two principal complexes investigated in this regard have been Cp*W(NO)CH2SiMe3)(eta(3)-CH2CHCHMe) (1) and Cp*W(NO)(CH2C6H5)-(eta(3)-CH2CHCHMe) (2). In has been found that treatment of 1 and 2 with the oxidant I-2 at - 60 degrees C produces Cp*W(NO)I-2 and terminallly functionalized ICH2SiMe3 and ICH2C6H5, respectively. Oxidation of 1 by H2O2 also results in the loss of the allyl ligand and production of known oxo peroxo complex Cp*W(O)(eta(2)-O-2)(CH2SiMe3). Treatment of 1 and 2 with electrophiles affords the products resulting from addition of the electrophile to the electron-rich terminus of the sigma(-)pi distorted allyl ligands in the reactants. Thus, reagents of the type E-X (E = triphenylcarbenium, H. catecholborane; X = Cl, BF4) liberate CH3CH = CHCH2E and form the organometallic products Cp*W(NO)(X)(CH2SiMe3) and cp*W(NO)(X)(CH2C6H5), respectively. Exposure of the tungsten alkyl allyl complexes to isocyanide reagents leads to the formation of complexes insertion of isocyanide into the tungsten-allyl linkages. For instance, reaction of 1 with 2,6-xylylisocyanide produces Cp*w-(NO)(CH2SiMe3)(eta(2)-CH3CH2CHCHC = NC6H3Me2) (4b). A similar reaction of 2 with 2.6-xylylisocyanide affords both unconjugated and conjugated isocyanide insertion products, while treatment of 2 with n-butylisocyanide produces primarily the conjugated product. Finally. exposure of these tungsten alkyl allyl complexes to 1000 psi of CO gas generally results in the desired migratory insertion of the CO into the metal-alkyl linkages to form acyl compounds. Hence, 1 is first converted into Cp*W(NO)-(C(O)CH2SiMe3)(eta 3-CH2CHCHMe), which then subsequently transforms into isolable Cp*W(NO)-(C(O)CH3)(eta 3-CH2CHCHMe) (7). Interestingly, 2 does not react with CO under these experimental conditions. Nevertheless, the generality of this mode of reactivity is established by the fact that similar treatment of four other Cp*(W)(NO)(CH2CMe3)(eta(3)-allyl) complexes with CO gas at elevated pressures does afford the corresponding acyl products (8-11). All new organometallic complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of several compounds have been established by X-ray crystallographic analyses.}, keywords = {ALLYL LIGANDS, CHEMISTRY, H BOND ACTIVATION, MOLYBDENUM, REACTIVITY}, isbn = {0276-7333}, url = {://000268455900035}, author = {Semproni, S. P. and Graham, P. M. and Buschhaus, M. S. A. and Patrick, B. O. and Legzdins,Peter} } @article {2116, title = {Amine-tethered N-heterocyclic carbene complexes of rhodium(I)}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {86}, number = {8}, year = {2008}, note = {ISI Document Delivery No.: 329TMTimes Cited: 9Cited Reference Count: 50Jong, Howard Patrick, Brian O. Fryzuk, Michael D.}, month = {Aug}, pages = {803-810}, type = {Article}, abstract = {A new family of rhodium-diene based complexes has been developed that incorporates an N-heterocyclic carbene ligand with an N-donor tether. The ligand is denoted (Mes)[CNH] 2 (where (Mes)[CNH] is 2,4,6-Me3C6H2NC3H2NCH2CH2NH-2,4,6-Me3C6H2) and (Mes)[CN] for the amido form. The synthesis of the (Mes)[CNH] ligand involves reaction of N-mesitylimidazole with 2-chloroethyl-N-mesitylamine under melt conditions, followed by deprotonation with KN(SiMe3)(2). The reaction of (Mes)[CNH] with [(diene)RhCl](2) results in the formation of the monodentate complexes, (Mes)[CNH]Rh(diene)Cl (where diene = 1,5-cyclooctadiene (COD): 3a; diene = 2,5-norbornadiene (NBD): 3b). Bidentate variants could be isolated as either a neutral species, (Mes)[CN]Rh(diene) 4a-4b, via deprotonation, or an ionic analogue such as [(Mes)[CNH]Rh(diene)]BF4 5a-5b by reaction with NaBF4. Compounds 4-5 are the first examples of rhodium compounds that contained a bidentate NHC ligand with a pendant amino or amido donor. Complexes 3-5 were characterized fully and the solid-state single crystal X-ray structures of 3a, 4a, and 5b are discussed. The utility of these complexes as catalyst precursors for hydrogenation reactions was examined and it was determined that these systems are not significantly more active than colloidal rhodium when parallel reactions were run. Various methods of transfer hydrogenations were also investigated with 3a, which did not yield an appreciable conversion of either benzophenone or N-benzylideneaniline as substrates.}, keywords = {CATALYSIS, HYDROGENATION, HYDROSILYLATION CATALYSTS, imines, IRIDIUM, KETONES, LIGANDS, N-heterocyclic carbene, REACTIVITY, rhodium, SEARCH, STABLE CARBENES, TRANSFER HYDROGENATION}, isbn = {0008-4042}, url = {://000257893500010}, author = {Jong, H. and Patrick, B. O. and Fryzuk,Michael D.} } @article {2168, title = {The complexes: RhCl(P-N)(THP), where P-N is P,N-chelated o-diphenylphosphino-N,N-dimethylaniline and THP is tris(hydroxymethyl)phosphine, and RhCl[(O)P-N][THP(O)] containing O-bonded phosphine oxides}, journal = {Inorganica Chimica Acta}, volume = {361}, number = {11}, year = {2008}, note = {ISI Document Delivery No.: 323VATimes Cited: 3Cited Reference Count: 42Lorenzini, Fabio Patrick, Brian O. James, Brian R.}, month = {Jul}, pages = {3199-3204}, type = {Article}, abstract = {{The complex RhCl(P-N)(THP) (1) is synthesized under argon from RhCl(cod)(THP) and P-N, and is structurally characterized; P-N = P, N-chelated o-diphenylphosphino-N,N-dimethylaniline}, keywords = {BEARING O-N, BIDENTATE PHOSPHINES, CATALYTIC-OXIDATION, HYDROFORMYLATION, LIGANDS, LOW-TEMPERATURE, N-DIMETHYLANILINYL SUBSTITUENTS, OXIDATION, PALLADIUM(II) COMPLEXES, phosphanes, phosphine oxides, phosphines, REACTIVITY, RHODIUM COMPLEXES, RHODIUM(I) COMPLEXES, X-ray structure}, isbn = {0020-1693}, url = {://000257475300029}, author = {Lorenzini, F. and Patrick, B. O. and James, Brian R.} } @article {2290, title = {Mass spectrometric identification of formaldehyde-induced peptide modifications under in vivo protein cross-linking conditions}, journal = {Analytica Chimica Acta}, volume = {618}, number = {2}, year = {2008}, note = {ISI Document Delivery No.: 317FDTimes Cited: 10Cited Reference Count: 19Toews, Judy Rogalski, Jason C. Clark, Thomas J. Kast, Juergen}, month = {Jun}, pages = {168-183}, type = {Article}, abstract = {Formaldehyde cross-linking of proteins is emerging as a novel approach to study protein-protein interactions in living cells. It has been shown to be compatible with standard techniques used in functional proteomics such as affinity-based protein enrichment, enzymatic digestion, and mass spectrometric protein identification. So far, the lack of knowledge on formaldehyde-induced protein modifications and suitable mass spectrometric methods for their targeted detection has impeded the identification of the different types of crosslinked peptides in these samples. In particular, it has remained unclear whether in vitro studies that identified a multitude of amino acid residues reacting with formaldehyde over the course of several days are suitable substitutes for the much shorter reaction times of 10-20 min used in cross-linking experiments in living cells. The current study on model peptides identifies amino-termini as well as lysine, tryptophan, and cysteine side chains, i.e. a small subset of those modified after several days, as the major reactive sites under such conditions, and suggests relative position in the peptide sequence as well as sequence microenvironment to be important factors that govern reactivity. Using MALDI-MS, mass increases of 12 Da on amino groups and 30 Da on cysteines were detected as the major reaction products, while peptide fragment ion analysis by tandem mass spectrometry was used to localize the actual modification sites on a peptide. Non-specific cross-linking was absent, and could only be detected with low yield at elevated peptide concentrations. The detailed knowledge on the constraints and products of the formaldehyde reaction with peptides after short incubation times presented in this study is expected to facilitate the targeted mass spectrometric analysis of proteins after in vivo formaldehyde cross-linking. (c) 2008 Elsevier B.V. All rights reserved.}, keywords = {Chemical modification, COMPLEXES, FORMALDEHYDE, MAP, mass, NETWORK, peptide fragmentation, protein cross-linking, PROTEOMICS, PURIFICATION, REACTIVITY, SPECTROMETRY}, isbn = {0003-2670}, url = {://000257004400006}, author = {Toews, J. and Rogalski, J. C. and Clark, T. J. and Kast, J.} } @article {2027, title = {Transformations of cyclic olefins mediated by tungsten nitrosyl complexes}, journal = {Organometallics}, volume = {27}, number = {18}, year = {2008}, note = {ISI Document Delivery No.: 348URTimes Cited: 3Cited Reference Count: 35Buschhaus, Miriam S. A. Pamplin, Craig B. Blackmore, Ian J. Legzdins, Peter}, month = {Sep}, pages = {4724-4738}, type = {Article}, abstract = {This report describes investigations that have elucidated the nature, extent, and mechanism of the cyclic-olefin oligomerization effected by a series of tungsten precatalysts, with particular focus on Cp*W(NO)(CH2CMe3)(2) (1) and Cp*W(NO)(CH2SiMe3)(eta(2)-CPhCH2) (2). Upon thermolysis, these precatalysts oligomerize simple cyclic olefins, from cyclopentene to cyclooctene, into ring-retaining oligomers as high as dodecamers (depending on the substrate) with remaining sites of unsaturation. Precatalyst initiation involves the coupling of one equivalent of the substrate with the reactive 16e intermediate thermally generated by the precatalyst (i.e., an alkylidene by 1 or an eta(2)-alkyne complex by 2), followed by rearrangement of the coupled ligand in the metal{\textquoteright}s coordination sphere either to an olefin or to a diene (with concomitant loss of two hydrogen atoms). The rearranged ligand is displaced from the metal center as two equivalents of substrate coordinate to form a putative bis-olefin complex, Cp*W(NO)(cyclic olefin)2, that represents the convergent entry point to the catalytic cycle for the precatalysts. The coordinated olefins undergo metal-mediated coupling to form a metallacyclopentane complex. The metallacycle then undergoes beta-hydrogen activation and reductive elimination to generate an eta(2)-cyclic-olefin dimer. Further incorporation of substrate leads to formation of trimers and higher oligomers. Alternatively, expulsion of any coordinated oligomer from the tungsten center regenerates the reactive bis-olefin complex. Finally, decomposition of the tungsten catalyst species is consistent with a bimetallic pathway. All new organometallic complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of several compounds have been established by X-ray crystallographic analyses.}, keywords = {1, 3-CYCLOHEXADIENE, ALKYLIDENE COMPLEXES, C-H ACTIVATION, CATALYTIC-ACTIVITY, CRYSTAL-STRUCTURES, CYCLOHEXENE, METATHESIS, MOLYBDENACYCLOBUTANES, MOLYBDENUM, REACTIVITY}, isbn = {0276-7333}, url = {://000259236100022}, author = {Buschhaus, M. S. A. and Pamplin, C. B. and Blackmore, I. J. and Legzdins,Peter} } @article {1637, title = {Engineering acyclic alkyl aryl ketones for enantioselective Norrish/Yang type II photochemistry in the crystalline state}, journal = {Crystengcomm}, volume = {8}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 050IUTimes Cited: 8Cited Reference Count: 9}, pages = {388-390}, type = {Article}, abstract = {While most alkyl aryl ketones fail to undergo the Norrish/Yang type II photoreaction in the solid state because they crystallize in conformations unfavorable for gamma-hydrogen atom abstraction, it was found with the aid of molecular mechanics that such is not the case for the 2-ethyl-1-arylbutan-1-one system; subsequent application of the solid state ionic chiral auxiliary method of asymmetric synthesis to derivatives of this ketone afforded the corresponding Yang cyclobutanol in enantiomeric excesses as high as 92\% at 91\% conversion.}, keywords = {ASYMMETRIC INDUCTION, REACTIVITY, SOLID-STATE}, isbn = {1466-8033}, url = {://000238081700006}, author = {Xia, W. J. and Yang, C. and Scheffer, J. R. and Patrick, B. O.} } @article {1579, title = {N-N splitting of a functionalized mu-eta(1):eta(2) coordinated N-2 ligand leading to a mu-nitrido mu-imido core: mechanistic insight from DFT}, journal = {Dalton Transactions}, number = {9}, year = {2006}, note = {ISI Document Delivery No.: 021NKTimes Cited: 5Cited Reference Count: 35}, pages = {1137-1140}, type = {Article}, abstract = {Silylation of a dinuclear tantalum complex containing a side- on end-on coordinated dinitrogen ligand initiates a sequence of reactions ultimately leading to a bis(mu-imido) structure. DFT is employed to determine the energetics of the entire reaction cascade. Particular emphasis is put on the unprecedented N-N cleavage reaction of the functionalized, mu-eta(1):eta(2) coordinated dinitrogen ligand. A mechanism for this reaction is derived theoretically and the corresponding transition state is determined.}, keywords = {ammonia, ATOMS, BOND-CLEAVAGE, END-ON, MOLECULAR CALCULATIONS, POTENTIALS, REACTIVITY, SIDE-ON, SPECTROSCOPIC PROPERTIES, TANTALUM DINITROGEN COMPLEX}, isbn = {1477-9226}, url = {://000235989700003}, author = {Studt, F. and MacKay, B. A. and Fryzuk,Michael D. and Tuczek, F.} } @article {1601, title = {A pentagonal pyramidal zirconium imido complex for catalytic hydroamination of unactivated alkenes}, journal = {Organometallics}, volume = {25}, number = {17}, year = {2006}, note = {ISI Document Delivery No.: 070PZTimes Cited: 66Cited Reference Count: 40Thomson, Robert K. Bexrud, Jason A. Schafer, Laurel L.}, month = {Aug}, pages = {4069-4071}, type = {Article}, abstract = {The first, isolable group 4 imido complexes capable of promoting intramolecular olefin hydroamination for the preparation of N-containing heterocycles are presented. The structurally characterized 6-coordinate bis(amidate)-supported zirconium imido complex is a rare example of distorted-pentagonal-pyramidal geometry.}, keywords = {ALKYNE HYDROAMINATION, allenes, AMIDATE COMPLEXES, BIS(AMIDATE) TITANIUM PRECATALYST, C-H ACTIVATION, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, INTRAMOLECULAR, REACTIVITY, TEMPERATURE, TI(NME2)(4)}, isbn = {0276-7333}, url = {://000239536800007}, author = {Thomson, R. K. and Bexrud, J. A. and Schafer, L. L.} } @article {1645, title = {Rhodium(III) peroxo complexes containing carbene and phosphine ligands}, journal = {Organometallics}, volume = {25}, number = {20}, year = {2006}, note = {ISI Document Delivery No.: 084QMTimes Cited: 12Cited Reference Count: 50Yu, Xiao-Yan Patrick, Brian O. James, Brian R.}, month = {Sep}, pages = {4870-4877}, type = {Article}, abstract = {The Rh(I) carbene precursors [RhCl(COE)(NHC)](2), where the N-heterocyclic carbene is 1,3-bis(2,6-diisopropylphenyl) imidazol-2-ylidene (IPr) or 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes), were used to synthesize the RhCl(NHC)(P-N) complexes 4 (NHC = IPr) and 5 (NHC = IMes), where P-N is P, N-chelated o-(diphenylphosphino)-N, N-dimethylaniline, and the corresponding cis-RhCl(NHC)(PPh3)(2) complexes 6 and 7. The synthesis of 4 surprisingly requires the reaction to be carried out under a hydrogen atmosphere and occurs via the intermediate dihydride RhCl(H)(2)(IPr)(P-N) (3). Complexes 4-7 in benzene readily undergo irreversible oxidative addition of O-2 to form the corresponding Rh(III) peroxide complexes 9-12. For comparative purposes, RhCl(PPh3)(P-N) (8) was synthesized from RhCl(PPh3)(3), and this also added O-2 to form a peroxo complex (13). All of the complexes were generally characterized by elemental analysis and H-1, P-31{H-1}, and C-13{H-1} NMR and IR spectroscopies and, in the cases of 9, 10, and 13, by X-ray crystallography.}, keywords = {14-ELECTRON RH(III), C-H ACTIVATION, CATALYTIC CYCLIZATION, DIOXYGEN ACTIVATION, hydride, HYDROFORMYLATION, HYDROGENATION, MOLECULAR-OXYGEN, REACTIVITY, TRANSITION-METAL-COMPLEXES}, isbn = {0276-7333}, url = {://000240549500028}, author = {Yu, X. Y. and Patrick, B. O. and James, Brian R.} } @article {1169, title = {Intermolecular activation of hydrocarbon C-H bonds initiated by the tungsten hydrocarbyl hydrido complexes Cp*W(NO)(R)(H)(PMe3) (R = alkyl, aryl)}, journal = {Organometallics}, volume = {24}, number = {4}, year = {2005}, note = {ISI Document Delivery No.: 896HITimes Cited: 5Cited Reference Count: 32}, month = {Feb}, pages = {638-649}, type = {Article}, abstract = {trans-CP*W(NO)(CH2EMe3)(H)(PMe3) (E = C, Si) complexes can be prepared by the hydrogenation at 1 atm of the appropriate Cp*W(NO)(CH2EMe3)(2) precursor in the presence of a slight excess of PMe3. (Our designation of a particular geometrical isomer as cis or trans in this family of complexes indicates the relative positions of the hydrocarbyl and the hydrido ligands in the base of a four-legged piano-stool molecular structure.) The use of D-2 in place of H-2 during these syntheses affords the corresponding trans-Cp*W(NO)(CH2EMe3)(D)(PMe3) (E = C, Si) complexes. The cis-Cp*W(NO)(CH2EMe3)(H)(PMe3) isomers are obtainable by C-H bond-activation reactions of the trans precursors. Thus, activation of SiMe4 by trans-Cp*W(NO)(CH2CMe3)(H)(PMe3) under ambient conditions produces cis-Cp*W(NO)(CH2SiMe3)(H)(PMe3). Similarly, activations of C6H6 and C6D6 at 20-27 degreesC by the trans-Cp*W(NO)(CH2EMe3)(H)(PMe3) complexes produce cis-Cp*W(NO)(C6H5)(H)(PMe3) and cisCp*W(NO)(C6D5)(D)(PMe3), respectively, and the solid-state molecular structure of the latter complex has been established by a single-crystal X-ray crystallographic analysis. Kinetic, mechanistic, and theoretical investigations of these benzene C-H activation processes are consistent with initial trans to cis isomerization of the reactants followed by intramolecular reductive elimination of EMe4 to form the 16-electron Cp*W(NO)(PMe3) intermediate. Subsequent oxidative addition of the incoming benzene substrate to this coordinatively unsaturated intermediate produces the final cis hydrido phenyl complex. These single C-H activation processes are the requisite first steps in the development of these organometallic complexes as catalysts for the selective functionalization of hydrocarbons. All new complexes have been characterized by conventional spectroscopic methods.}, keywords = {CALCULATIONS, density, EFFECTIVE CORE POTENTIALS, MOLECULAR, MOLYBDENUM, ORGANOMETALLIC NITROSYL CHEMISTRY, REACTIVITY}, isbn = {0276-7333}, url = {://000226924800024}, author = {Lee, K. and Legzdins,Peter and Pamplin, C. B. and Patrick, B. O. and Wada, K.} } @article {1060, title = {Intramolecular hydroamination of unactived olefins with Ti(NMe2)(4) as a precatalyst}, journal = {Organic Letters}, volume = {7}, number = {10}, year = {2005}, note = {ISI Document Delivery No.: 924NCTimes Cited: 104Cited Reference Count: 59}, month = {May}, pages = {1959-1962}, type = {Article}, abstract = {[GRAPHICS] Commercially available Ti(NMe2)(4) has been used effectively as a precatalyst in a facile protocol for the intramolecular hydroamination of aminoalkenes to yield pyrrolidine and piperidine heterocyclic products with isolated yields up to 92\%. Germinally substituted substrates display the highest reactivity. This precatalyst is also effective for the hydroamination of activated internal alkenes, providing access to more complex heterocyclic target molecules.}, keywords = {ALKENE HYDROAMINATION, ALKYNE, AMIDO COMPLEXES, ANTI-MARKOVNIKOV, CATALYZED INTERMOLECULAR HYDROAMINATION, GROUP-3 METALS, HYDROAMINATION, IMIDO COMPLEXES, REACTIVITY, TITANIUM, ZIRCONIUM}, isbn = {1523-7060}, url = {://000228984500019}, author = {Bexrud, J. A. and Beard, J. D. and Leitch, D. C. and Schafer, L. L.} } @article {1270, title = {Lewis adducts of the side-on end-on dinitrogen-bridged complex [{(NPN)Ta}(2)(mu-H)(2)(mu-eta(1):eta(2)-N-2)] with AlMe3, GaMe3, and B(C6F5)(3): Synthesis, structure, and spectroscopic properties}, journal = {Chemistry-a European Journal}, volume = {11}, number = {2}, year = {2005}, note = {ISI Document Delivery No.: 887VLTimes Cited: 12Cited Reference Count: 49}, month = {Jan}, pages = {604-618}, type = {Article}, abstract = {{Reaction of the side-on end-on dinitrogen complex [{(NPN)Ta}(2)(mu- H)(2)(mu-eta(1):eta(2)-N-2)] (1; in which NPN= (PhNSiMe2CH2)(2)PPh), with the Lewis acids XR3 results in the adducts [{(NPN)Ta}(2)(mu-H)(2)(mu-eta(1):eta(2)-NNXR3)]}, keywords = {CHEMISTRY, CLEAVAGE, COORDINATED, density functional calculations, DINITROGEN, DINITROGEN COMPLEXES, DINUCLEAR TANTALUM COMPLEX, EFFECTIVE CORE POTENTIALS, FIXATION, MOLECULAR CALCULATIONS, MOLYBDENUM CENTER, N-2 LIGAND, NITROGEN, Raman spectroscopy, REACTIVITY, tantalum, TRIS(PENTAFLUOROPHENYL)BORANE}, isbn = {0947-6539}, url = {://000226333500014}, author = {Studt, F. and MacKay, B. A. and Johnson, S. A. and Patrick, B. O. and Fryzuk,Michael D. and Tuczek, F.} } @article {1064, title = {Molecular mechanics-assisted crystal engineering of solid state photoreactions: application to the Yang photocyclization of alpha-1-norbornylacetophenone derivatives}, journal = {Tetrahedron Letters}, volume = {46}, number = {7}, year = {2005}, note = {ISI Document Delivery No.: 895FRTimes Cited: 3Cited Reference Count: 11}, month = {Feb}, pages = {1141-1144}, type = {Article}, abstract = {Based on molecular mechanics, Yang photocyclization of alpha-1-norbornylacetophenone derivatives in the crystalline state was engineered through methylation adjacent to the carbonyl group, thus changing the conformation in the crystal and leading to enhanced diastereo- and enantioselectivity. (C) 2004 Elsevier Ltd. All rights reserved.}, keywords = {ASYMMETRIC INDUCTION, crystal engineering, GEOMETRIC REQUIREMENTS, II REACTION, ionic chiral auxiliaries, REACTIVITY, solid state photochemistry, X-RAY CRYSTALLOGRAPHY, Yang photocyclization}, isbn = {0040-4039}, url = {://000226846800021}, author = {Botoshansky, M. and Braga, D. and Kaftory, M. and Maini, L. and Patrick, B. O. and Scheffer, J. R. and Wang, K. Y.} } @article {878, title = {New details concerning the reactions of nitric oxide with vanadium tetrachloride}, journal = {Inorganic Chemistry}, volume = {43}, number = {22}, year = {2004}, note = {ISI Document Delivery No.: 866SHTimes Cited: 2Cited Reference Count: 35}, month = {Nov}, pages = {7227-7233}, type = {Article}, abstract = {The slow addition of NO to a CCl4 solution Of VCl4 reproducibly forms the known polymer [V(NO)(3)Cl-2](n) as a dark brown powder. Treatment of a CH2Cl2 suspension of [V(NO)(3)Cl-2], with excess THF generates mer-(THF)(3)V(NO)Cl-2 (1) which can be isolated as an orange crystalline material in 55\% yield. The reaction of 1 with excess MeCN or 1 equiv of trimpsi (trimpsi = (BuSi)-Bu-t(CH2PMe2)(3)) provides yellow-orange (MeCN)(3)V(NO)Cl-2.MeCN (2.MeCN) and yellow (trimpsi)V(NO)Cl-2 (3), respectively. A black, crystalline complex formulated as [NO][VCl5] (4) is formed by the slow addition of NO to neat VCl4 or by the reaction of excess CINO with neat VCl4. Complex 4 is extremely air- and moisture-sensitive, and IR spectroscopy suggests that in solutions and in the gas phase it dissociates back into VCl4 and CINO. Reaction of 4 with excess [NEt3(CH2Ph)]Cl generates [NEt3(CH2Ph)](2)[VCl6].2CH(2)Cl(2) (5.2CH(2)Cl(2)), which can be isolated as deep-red crystals in 51\% yield. All new complexes have been characterized by conventional spectroscopic methods, and the solid-state molecular structures of 1, 2.MeCN, and 5.2CH(2)Cl(2) have been established by single-crystal X-ray diffraction analyses.}, keywords = {(BUSI)-BU-T(CH2PME2)(3), (TRIMPSI)M(CO)(2)(NO) COMPLEXES M, CHLORIDE, COORDINATION-COMPOUNDS, CRYSTAL-STRUCTURE, DICHLOROTRINITROSYLVANADIUM, IR-SPECTRUM, NITROSYLS, REACTIVITY, TRIMPSI}, isbn = {0020-1669}, url = {://000224792900049}, author = {Hayton, T. W. and Patrick, B. O. and Legzdins,Peter} } @article {922, title = {Scandium-catalyzed intramolecular hydroamination. Development of a highly active cationic catalyst}, journal = {Organometallics}, volume = {23}, number = {10}, year = {2004}, note = {ISI Document Delivery No.: 818FNTimes Cited: 100Cited Reference Count: 37}, month = {May}, pages = {2234-2237}, type = {Article}, abstract = {The scandium-catalyzed intramolecular hydroamination of alkynes and alkenes is reported. Complex structure/catalyst activity investigations resulted in the identification of a highly catalytically active cationic, beta-diketiminato scandium complex.}, keywords = {ALKENES, ALKYNES, AMIDO COMPLEXES, BETA-DIKETIMINATO LIGANDS, DERIVATIVES, GROUP-3 METALS, ORGANOSCANDIUM, REACTIVITY, YTTRIUM, ZIRCONIUM}, isbn = {0276-7333}, url = {://000221231100006}, author = {Lauterwasser, F. and Hayes, P. G. and Brase, S. and Piers, W. E. and Schafer, L. L.} } @article {613, title = {Diastereoselective formation of a dipalladium(I) complex supported by a bridging tetradentate ligand, and oxidative addition of RS-H across a phosphine-bridged Pd-I-Pd-I bond}, journal = {Chemical Communications}, number = {8}, year = {2003}, note = {ISI Document Delivery No.: 663LZTimes Cited: 7Cited Reference Count: 13}, pages = {988-989}, type = {Article}, abstract = {{The ligand CH2(P(o-C6H4NMe2)(2))(2) (dmapm) gives access to the first example of a dipalladium(I) complex supported by a tetradentate ligand, Pd2Cl2(mu-N,P,P,N-dmapm), which, unlike the well-known Pd2X2(mu-dppm)(2) complexes (X = halide}, keywords = {BEHAVIOR, H2S, palladium, REACTIVITY}, isbn = {1359-7345}, url = {://000182008200029}, author = {Foo, S. J. L. and Jones, N. D. and Patrick, B. O. and James, Brian R.} } @article {618, title = {Hydrosilylation of a dinuclear tantalum dinitrogen complex: Cleavage of N-2 and functionalization of both nitrogen atoms}, journal = {Journal of the American Chemical Society}, volume = {125}, number = {11}, year = {2003}, note = {ISI Document Delivery No.: 655MFTimes Cited: 54Cited Reference Count: 20}, month = {Mar}, pages = {3234-3235}, type = {Article}, keywords = {BONDS, CHEMISTRY, COORDINATED DINITROGEN, END-ON, FIXATION, LIGAND, REACTIVITY, REDUCTION, SIDE-ON, SILANES}, isbn = {0002-7863}, url = {://000181555600022}, author = {Fryzuk,Michael D. and MacKay, B. A. and Patrick, B. O.} } @article {710, title = {Preorganization of achiral molecules for asymmetric synthesis through crystallization-induced immobilization in homochiral conformations}, journal = {Angewandte Chemie-International Edition}, volume = {42}, number = {32}, year = {2003}, note = {ISI Document Delivery No.: 716PRTimes Cited: 19Cited Reference Count: 24}, pages = {3775-3777}, type = {Article}, keywords = {asymmetric synthesis, CRYSTAL, crystal engineering, GEOMETRIC REQUIREMENTS, II, INDUCTION, KETONES, PHOTOCHEMICAL-REACTIONS, PHOTOCHEMISTRY, PHOTOCYCLIZATION, reaction, REACTIONS, REACTIVITY, SOLID-STATE, topochemistry}, isbn = {1433-7851}, url = {://000185038000009}, author = {Patrick, B. O. and Scheffer, J. R. and Scott, C.} } @article {706, title = {Thermal activation of hydrocarbon C-H bonds by Cp*M(NO) complexes of molybdenum and tungsten}, journal = {Accounts of Chemical Research}, volume = {36}, number = {4}, year = {2003}, note = {ISI Document Delivery No.: 669GJTimes Cited: 54Cited Reference Count: 36}, month = {Apr}, pages = {223-233}, type = {Review}, abstract = {Gentle thermolysis of appropriate Cp*M(NO)(hydrocarbyl)(2) complexes (Cp* = eta(5)-C5Me5) of molybdenum and tungsten results in loss of hydrocarbon and the transient formation of 16-electron Cp*M(NO)-containing complexes such as Cp*M(NO)(alkylidene), Cp*M(NO)(eta(2)-benzyne), Cp*M(NO)(eta(2)-acetylene), and Cp*M(NO)(eta(2)-allene) (M = Mo, W). These intermediates effect the single, double, or triple activation of hydrocarbon C-H bonds intermolecularly, the first step of these activations being the reverse of the transformations by which they were generated. This Account summarizes the various types of C-H activations that have been effected with these nitrosyl complexes and also describes the results of kinetic, mechanistic, and theoretical investigations of these processes.}, keywords = {ALKANES, ALKYLIDENE COMPLEXES, ARENES, CHEMISTRY, INTERMEDIATE, NITROSYL, REACTIVITY, REDUCTIVE ELIMINATION, THERMOLYSIS, TRANSITION-METAL BONDS}, isbn = {0001-4842}, url = {://000182343300001}, author = {Pamplin, C. B. and Legzdins,Peter} } @article {395, title = {(eta(5)-cyclopentadienyl)(p-fluorophenoxo)(nitrosyl)(trimethylsilyl- methyl)molybdenum(II)}, journal = {Acta Crystallographica Section C-Crystal Structure Communications}, volume = {58}, year = {2002}, note = {ISI Document Delivery No.: 520RZTimes Cited: 1Cited Reference Count: 11Part 2}, month = {Feb}, pages = {m68-m69}, type = {Article}, abstract = {The title complex, [Mo(C5H5)(C6H4FO)(C4H11Si)(NO)], is formed by reacting CpMo(NO)(CH2SiMe3)(2), where Cp is cyclopentadienyl, with one equivalent of p-FC6H4OH. The complex exhibits the expected piano-stool molecular structure, with a linear nitrosyl ligand [Mo-N-O 168.2 (2)degrees] having Mo-N and N-O distances of 1.764 (2) and 1.207 (3) Angstrom, respectively. The phenoxo Mo-O distance of 1.945 (2) Angstrom is suggestive of some multiple-bond character.}, keywords = {BONDS, COMPLEXES, FRAGMENT, REACTIVITY}, isbn = {0108-2701}, url = {://000173796300004}, author = {Hayton, T. W. and Legzdins,Peter and Rettig, S. J.} } @article {537, title = {Parallel modes of C-H bond activation initiated by Cp*Mo(NO)(CH2CMe3)(C6H5) at ambient temperatures}, journal = {Journal of the American Chemical Society}, volume = {124}, number = {33}, year = {2002}, note = {ISI Document Delivery No.: 584EVTimes Cited: 15Cited Reference Count: 32}, month = {Aug}, pages = {9680-9681}, type = {Article}, keywords = {ALKANES, ARYNE COMPLEXES, CHEMISTRY, HYDROCARBONS, INTERMEDIATE, METAL-COMPLEXES, MOLYBDENUM, REACTIVITY, THERMOLYSIS, TUNGSTEN ALKYLIDENE COMPLEXES}, isbn = {0002-7863}, url = {://000177455000012}, author = {Wada, K. and Pamplin, C. B. and Legzdins,Peter} } @article {379, title = {Phosphorus phenyl-group activation by reduced zirconium and niobium complexes stabilized by the [P2N2] macrocycle}, journal = {Journal of the American Chemical Society}, volume = {124}, number = {4}, year = {2002}, note = {ISI Document Delivery No.: 514THTimes Cited: 21Cited Reference Count: 23}, month = {Jan}, pages = {516-517}, type = {Article}, keywords = {ARENE COMPLEX, CHEMISTRY, CRYSTAL, DERIVATIVES, DINITROGEN, LIGAND, REACTIVITY, TITANIUM}, isbn = {0002-7863}, url = {://000173456800002}, author = {Fryzuk,Michael D. and Kozak, C. M. and Mehrkhodavandi, Parisa and Morello, L. and Patrick, B. O. and Rettig, S. J.} } @article {5171, title = {An electrochemical experiment to monitor the isomerization of trans- to cis-[RuCl2(dppb)[phen)] - An undergraduate cyclic voltammetry experiment for inorganic chemistry}, journal = {Journal of Chemical Education}, volume = {78}, number = {1}, year = {2001}, note = {ISI Document Delivery No.: 382HZTimes Cited: 9Cited Reference Count: 7}, month = {Jan}, pages = {89-90}, type = {Article}, keywords = {COMPLEXES, REACTIVITY}, isbn = {0021-9584}, url = {://000165818000034}, author = {Queiroz, S. L. and de Araujo, M. P. and Batista, A. A. and Macfarlane, K. S. and James, Brian R.} } @article {5157, title = {The nitrous oxide complex, RuCl2(eta(1)-N2O)(P-N)(PPh3) (P-N = [o-(N,N-dimethylamino)phenyl]diphenylphosphine); Low temperature conversion of N2O to N-2 and O-2}, journal = {Journal of the American Chemical Society}, volume = {123}, number = {35}, year = {2001}, note = {ISI Document Delivery No.: 467XNTimes Cited: 22Cited Reference Count: 62}, month = {Sep}, pages = {8596-8597}, type = {Article}, keywords = {3-COORDINATE MOLYBDENUM(III), ADSORBED N2O, BOND, CRYSTAL-STRUCTURE, DECOMPOSITION, LEWIS ACIDITY, N-15 NMR, OXYGEN-ATOM TRANSFER, REACTIVITY, REDUCTASE}, isbn = {0002-7863}, url = {://000170729200019}, author = {Pamplin, C. B. and Ma, E. S. F. and Safari, N. and Rettig, S. J. and James, Brian R.} } @article {5197, title = {O-protonation of a terminal nitrosyl group to form an eta(1)-hydroxylimido ligand}, journal = {Journal of the American Chemical Society}, volume = {123}, number = {33}, year = {2001}, note = {ISI Document Delivery No.: 463TWTimes Cited: 9Cited Reference Count: 26}, month = {Aug}, pages = {8143-8144}, type = {Article}, keywords = {CHEMISTRY, COMPLEXES, CRYSTAL-STRUCTURE, METAL, MOLYBDENUM, NITRIC-OXIDE, REACTIVITY, REDUCTION, TUNGSTEN}, isbn = {0002-7863}, url = {://000170494200032}, author = {Sharp, W. B. and Legzdins,Peter and Patrick, B. O.} } @article {4998, title = {Organometallic oxides: Oxidation of the cubane [(eta-C5R5)Cr(mu(3)-O)](4) and the structures and magnetic properties of the salts {[(eta-C5R5)Cr(mu(3)-O)](4)}{tcnq} and {[(eta-C5R5)Cr(mu(3)-O)](4)}{BF4}, journal = {Organometallics}, volume = {20}, number = {9}, year = {2001}, note = {ISI Document Delivery No.: 428DKTimes Cited: 5Cited Reference Count: 41}, month = {Apr}, pages = {1840-1848}, type = {Article}, abstract = {Differential pulse and current voltammetry for the cubane-like clusters [(eta -C5R5)Cr(mu (3)-O)](4) (R = H, Me; R-5 = H4Me) showed that [(eta -C5H4Me)Cr(mu (3)-O)](4) and [(eta -C5Me5)Cr(mu (3)-O)](4) were oxidized to {[(eta -C5R5)Cr(mu (3)-O)](4)}(+) and then to {[(eta -C5R5)Cr(mu (3)-O)](4)}(2+), but [(eta -C5H5)-Cr(mu (3)-O)](4) was oxidized only to {[(eta -C5H5)Cr(mu (3)-O)](4)}(+). Oxidation of [(eta -C5Me5)Cr(mu (3)-O)](4) (1) by AgBF4 or tcnq gave {[(eta -C5Me5)Cr(mu (3)-O)](4)}{BF4} (2) {[(eta -C5Me5)Cr(mu (3)-O)](4)}{tcnq} (3). It was shown by X-ray diffraction that the average Cr-Cr, Cr-O, and Cr-Cp* distances in 2 and 3 were 0.034(2), 0.007(5), and 0.02(1) Angstrom shorter than those in 1, respectively. Compounds 1 2, and 3 were antiferromagnetic., with similar intracluster exchange coupling constants, J (-262(23), -211(34), and -266(46) cm(-1), respectively). There was coupling between unpaired electrons on {[(eta -C5Me5)Cr(mu (3)-O)](4)}(+) and {tcnq}(-) in 3 at temperatures below 110 Ii.}, keywords = {<(ETA-C5H5)CR(MU-3-O)>4, CLUSTERS, COMPLEXES, CRYSTAL-STRUCTURES, MONONUCLEAR, REACTIVITY, SINGLE-MOLECULE MAGNETS, TCNQ, X-ray structure}, isbn = {0276-7333}, url = {://000168445800017}, author = {Allen, D. P. and Bottomley, F. and Day, R. W. and Decken, A. and Sanchez, V. and Summers, D. A. and Thompson, R. C.} } @article {5043, title = {A remarkable temperature-dependent, accidental degeneracy of P-31 NMR chemical shifts in Ru(II) diphosphine/diimine complexes}, journal = {Chemical Communications}, number = {17}, year = {2001}, note = {ISI Document Delivery No.: 469DQTimes Cited: 10Cited Reference Count: 26}, month = {Sep}, pages = {1570-1571}, type = {Article}, abstract = {Several cis-RUX2((R)-BINAP)(diimine) complexes have been prepared, and many of these exhibit an unusual temperature-dependent, accidental degeneracy of the P-31 shifts in their solution NMR spectra.}, keywords = {ASYMMETRIC HYDROGENATION, BINAP, CATALYSIS, CHEMISTRY, DERIVATIVES, KETONES, LIGANDS, PHOSPHINE COMPLEXES, REACTIVITY, RUTHENIUM(II) COMPLEXES}, isbn = {1359-7345}, url = {://000170798800019}, author = {Cyr, P. W. and Patrick, B. O. and James, Brian R.} } @article {5170, title = {Synthesis of [RuCl2(dppb)(PPh3)] and identification of the cis- and trans-[RuCl2(dppb)(phen)] geometrical isomers via P-31{H-1} NMR spectroscopy - An undergraduate experiment for inorganic chemistry}, journal = {Journal of Chemical Education}, volume = {78}, number = {1}, year = {2001}, note = {ISI Document Delivery No.: 382HZTimes Cited: 8Cited Reference Count: 9}, month = {Jan}, pages = {87-89}, type = {Article}, keywords = {COMPLEXES, P-31, REACTIVITY, RUTHENIUM(II)}, isbn = {0021-9584}, url = {://000165818000033}, author = {Queiroz, S. L. and de Araujo, M. P. and Batista, A. A. and Macfarlane, K. S. and James, Brian R.} } @article {4838, title = {Cr(NAr)(O)(NPr2i)(Ar): a strongly-bent monoimido complex resulting from nitrosyl ligand cleavage}, journal = {Chemical Communications}, number = {18}, year = {2000}, note = {ISI Document Delivery No.: 352VQTimes Cited: 10Cited Reference Count: 26}, pages = {1809-1810}, type = {Article}, abstract = {The molecular structure of Cr(NAr)(O)(NPr2i)(Ar) (Ar = 2-MeC6H4) is analysed by X-ray crystallographic and density functional theoretical techniques.}, keywords = {BIS(IMIDO) COMPLEXES, CATALYSTS, CHROMIUM(VI), CHROMIUM-(VI), IMIDO LIGAND, MOLYBDENUM(VI), PRECURSORS, RAY CRYSTAL-STRUCTURE, REACTIVITY}, isbn = {1359-7345}, url = {://000089238900051}, author = {Jandciu, E. W. and Legzdins,Peter and McNeil, W. S. and Patrick, B. O. and Smith, K. M.} } @article {4572, title = {11,12-bis(diethylaminomethyl)-9,10-dihydro-9,10-ethenoanthracene: A probe for the heavy atom effect in solid state photoreactions}, journal = {Tetrahedron}, volume = {55}, number = {8}, year = {1999}, note = {ISI Document Delivery No.: 167FYTimes Cited: 2Cited Reference Count: 26}, month = {Feb}, pages = {2171-2182}, type = {Article}, abstract = {The photochemistry of title compound 2 and its hydrogen halide salts was investigated in solution and in the solid state. In the solid state the halide ions were shown to cause a heavy atom effect that was not observed in solution. The orientation of the halide ions towards the chromophore was determined on the basis of the corresponding structures in the solid state as determined by X-ray crystallography. (C) 1999 Elsevier Science Ltd. All rights reserved.}, keywords = {CRYSTALLINE, MOLECULES, ORGANIC-PHOTOCHEMISTRY, REACTIVITY, SALTS}, isbn = {0040-4020}, url = {://000078622900004}, author = {Ihmels, H. and Patrick, B. O. and Scheffer, J. R. and Trotter, J.} } @article {4572, title = {11,12-bis(diethylaminomethyl)-9,10-dihydro-9,10-ethenoanthracene: A probe for the heavy atom effect in solid state photoreactions}, journal = {Tetrahedron}, volume = {55}, number = {8}, year = {1999}, note = {ISI Document Delivery No.: 167FYTimes Cited: 2Cited Reference Count: 26}, month = {Feb}, pages = {2171-2182}, type = {Article}, abstract = {The photochemistry of title compound 2 and its hydrogen halide salts was investigated in solution and in the solid state. In the solid state the halide ions were shown to cause a heavy atom effect that was not observed in solution. The orientation of the halide ions towards the chromophore was determined on the basis of the corresponding structures in the solid state as determined by X-ray crystallography. (C) 1999 Elsevier Science Ltd. All rights reserved.}, keywords = {CRYSTALLINE, MOLECULES, ORGANIC-PHOTOCHEMISTRY, REACTIVITY, SALTS}, isbn = {0040-4020}, url = {://000078622900004}, author = {Ihmels, H. and Patrick, B. O. and Scheffer, J. R. and Trotter, J.} } @article {4669, title = {A computational study of two-state conformational changes in 16-electron [CpW(NO)(L)] complexes (L = PH3, CO, CH2, HCCH, H2CCH2)}, journal = {Chemistry-a European Journal}, volume = {5}, number = {5}, year = {1999}, note = {ISI Document Delivery No.: 194UQTimes Cited: 20Cited Reference Count: 52}, month = {May}, pages = {1598-1608}, type = {Article}, abstract = {Electronically and coordinatively unsaturated [Cp*W(NO)(L)] complexes have been postulated as intermediates in several related systems. Model [CpW(NO)(L)] compounds (L= PH3, CO, CH2, H2CCH2, HCCH) have been investigated theoretically by means of density functional theory computational techniques. The structural parameters calculated for saturated [CpW(NO)(PH,)(L)] complexes are in good agreement with the solid-state molecular structures determined crystallographically for the corresponding [Cp*W(NO)(PMe3)(L)] compounds. The 16-electron, singlet [CpW(NO)(L)] species have geometries comparable to those of the same fragment in the phosphine adducts and include a highly pyramidal conformation at W. The energy of the triplet spin state is calculated to be close to or even lower than that of the singlet state for these unsaturated compounds, and depends largely on the pi-bonding capabilities of L (Delta Es-t=Delta E-t-Delta E-s = - 3.3 kcalmol(-1) (PH3), + 2.8 (CO), + 2.4 (CH2), +6.3 (H2CCH2), -2.3 (HCCH)). The optimization of partially constrained structures in both spin states allows for a conformational analysis of the [CpW(NO)(L)] species. The inversion of the conformation of the pyramidal singlet [CpW(NO)(L)] complexes via the planar-at-W triplet species (two-state pathway) is calculated to be competitive with the equivalent process solely along the singlet spin hypersurface. Rotation of the W-CH, bond in the singlet carbene species is also found to proceed more readily via a two-state pathway. The preferred alkyne conformation, the unusually stable triplet states, and the strong W-to-L sc-donation observed in these systems may all be rationalized by the relatively high energies of the occupied orbitals of the formally WO compounds.}, keywords = {ACTIVATION, CROSSOVER, density functional calculations, H BOND, LIGAND, ligand effects, MOLECULAR CALCULATIONS, ORGANOMETALLIC NITROSYL CHEMISTRY, OXIDATIVE ADDITION, pi interactions, PIANO-STOOL COMPLEXES, REACTIVITY, REDUCTIVE ELIMINATION, SPIN, SPIN-STATE, TUNGSTEN}, isbn = {0947-6539}, url = {://000080212600026}, author = {Smith, K. M. and Poli, R. and Legzdins,Peter} } @article {4651, title = {Dimeric rhodium mu-silylene and mu-eta(2)-silyl complexes: Catalytic silicon-silicon bond formation and x-ray structures of [{Pr(i)(2)PCH2CH2PPr(i)(2)}Rh](2)(mu-SiRR {\textquoteright})(2) (R = R {\textquoteright} = Ph and R = Me, R {\textquoteright} = Ph) and [{Pr(i)(2)PCH2CH2PPr(i)(2)}Rh(H)](2)(}, journal = {Organometallics}, volume = {18}, number = {6}, year = {1999}, note = {ISI Document Delivery No.: 178FRTimes Cited: 29Cited Reference Count: 32}, month = {Mar}, pages = {958-969}, type = {Article}, abstract = {The stoichiometric and catalytic reactions of secondary silanes with the rhodium hydride bridged dimer [(dippe)Rh](2)(mu-H)(2) (1; dippe = 1,2-bis(diisopropylphosphino)ethane) are described. The reaction of 1 with Ph2SiH2 results in the formation of the bis(mu-silylene) complex [(dippe)Rh](2)(mu-SiPh2)(2) (2a); a similar reaction ensues upon addition of MePhSiH2 or Me(p)TolSiH(2) ((P)Tol =p-tolyl) to 1 except that the bis(silylene) complexes exist as a mixture of cis and trans stereoisomers. Dimethylsilane reacts with 1 to generate the dinuclear complex [(dippe)Rh(H)](2)(mu-eta(2)-SiMe2)(2) (4d). The hydride dimer acts as a catalyst precursor for the dimerization of excess Ph2SiH2 to tetraphenyldisilane (Ph2SiHSiHPh2). A catalytic cycle is proposed that consists of dinuclear intermediates.}, keywords = {BONDS, hydride complexes, HYDROSILYLATION, REACTIVITY, SECONDARY SILANES, SI, TRANSITION-METAL COMPLEXES}, isbn = {0276-7333}, url = {://000079256000005}, author = {Rosenberg, L. and Fryzuk,Michael D. and Rettig, S. J.} } @article {4680, title = {Gas phase ion molecule chemistry of tetracarbonyl (eta(5)-cyclopentadienyl) vanadium by Fourier transform ion cyclotron resonance}, journal = {International Journal of Mass Spectrometry}, volume = {182}, year = {1999}, note = {ISI Document Delivery No.: 171QJTimes Cited: 1Cited Reference Count: 36}, month = {Mar}, pages = {139-148}, type = {Article}, abstract = {The kinetics of the reactions between the CpV(CO)(4) molecule and its fragment cations and anions have been examined using Fourier transform ion cyclotron resonance (FTICR) techniques. With 25 eV electron impact ionization the fragment cations V+ and CpV(CO)(n=0-4)(+) react principally by charge exchange or by condensation with the parent neutral molecule. Rate constants for these pathways have been determined along with kinetic evidence for the existence of excited state cations. Some of the product cations show unexpected stability despite their large formal electron deficiency. Exchange of carbonyl ligands was also observed. Under 2.5 eV electron impact, only two anions are produced: CpV(CO)(n=2,3)(-), both of which are unreactive with the parent neutral. (C) 1999 Elsevier Science B.V.}, keywords = {BOND-DISSOCIATION ENERGIES, CARBONYL CLUSTER FRAGMENTS, carbonyl ligands, FE(CO)5, Fourier transform ion cyclotron resonance mass, gas phase ion chemistry, iron, METAL BONDS, MN+, PENTACARBONYL, REACTIVITY, SPECTROMETRY, STATE, SYSTEMS, V+}, isbn = {1387-3806}, url = {://000078874700015}, author = {Taylor, S. M. and Comisarow, M. B.} } @article {4548, title = {One-electron oxidation of paramagnetic chromium(II) alkyl complexes with alkyl halides: synthesis and structure of five-coordinate chromium(III) complexes}, journal = {Journal of the Chemical Society-Dalton Transactions}, number = {2}, year = {1999}, note = {ISI Document Delivery No.: 162JPTimes Cited: 18Cited Reference Count: 69}, month = {Jan}, pages = {147-154}, type = {Article}, abstract = {The reaction of square-planar, high-spin CrR[N(SiMe2CH2PPh2)(2)] (R = Me, CH2SiMe3) with alkyl halides (MeI, CF3CH2I, MeBr, PhCH2Cl) generates one-electron oxidation products Cr(R)X[N(SiMe2CH2PPh2)(2)], unusual examples of five-coordinate chromium(III) complexes. Cr(Me)Br[N(SiMe2CH2PPh2)(2)] and Cr(CH2SiMe3)Cl[N(SiMe2CH2PPh2)(2)] have structurally characterized. Alkylation of the latter complex with LiCH2SiMe3 gave a five-coordinate Cr(III) dialkyl complex Cr(CH2SiMe3)(2)[N(SiMe2CH2PPh2)(2)](2), which was structurally characterized as well. Attempts to isolate sterically unencumbered Cr(III) dialkyl (e.g., dimethyl) complexes resulted in decomposition. Addition of an excess of PhCH2Cl to {[(Ph2PCH2SiMe2)(2)N]Cr}(2)(mu-Cl)(2) resulted in halide-transfer to form CrCl2(TNF)[N(SiMe2CH2PPh2)(2)] in low yield. Reaction of the low-spin CrCp[N(SiMe2CH2PPh2)(2)] complex with PhCH2Cl, however, gave both Cr(Cp)(CH2Ph)[N(SiMe2CH2PPh2)(2)] and Cr(CP)Cl[N(SiMe2CH2CH2PPh2)(2)]. The five five-coordinate Cr(III) alkyl halide complexes do not polymerize ethylene at 60 degrees C and 1 atm; the dialkyl complex Cr(CH2SiMe3)(2)[N(SiMe2CH2PPh2)(2)] does catalyze polyethylene formation but is quickly deactivated. A discussion comparing the structural distortions observed in these five-coordinate high-spin d(3) Cr(III) complexes with those observed in the analogous low-spin d(6) Ir(III) complexes is presented.}, keywords = {17-ELECTRON, 5-COORDINATE, ATOM TRANSFER-REACTIONS, CHEMISTRY, CRYSTAL-STRUCTURE, D6 ML5 COMPLEXES, NMR-SPECTROSCOPY, ORGANIC HALIDES, POLYMERIZATION, REACTIVITY}, isbn = {0300-9246}, url = {://000078342700010}, author = {Fryzuk,Michael D. and Leznoff, D. B. and Rettig, S. J. and Young, V. G.} } @article {4546, title = {Synthesis and structure of the tantalum trimethyl complex [P2N2]TaMe3 and its conversion to the tantalum methylidene species [P2N2]Ta = CH2(Me) ([P2N2] = PhP(CH2SiMe2NSiMe2CH2)(2)PPh)}, journal = {Organometallics}, volume = {18}, number = {20}, year = {1999}, note = {ISI Document Delivery No.: 244CDTimes Cited: 25Cited Reference Count: 42}, month = {Sep}, pages = {4059-4067}, type = {Article}, abstract = {A tantalum(V) trimethyl complex and its photolysis product, a relatively stable tantalum(V) methyl methylidene, were prepared using the macrocyclic bis(amido-phosphine) PhP(CH2SiMe2NSiMe2CH2)(2)PPh, abbreviated [P2N2], as an ancillary ligand. The methylidene precursor [P2N2]TaMe3 is generated by the reaction of [P2N2]Li-2. C4H8O2 (C4H8O2 = 1,4-dioxane) with TaMe3Cl2. The solid-state X-ray molecular structure demonstrates that the geometry of [P2N2]TaMe3 is a seven-coordinate capped trigonal prism, and NMR studies confirm this is also true in solution at low temperature. Photolysis with a UV source generates [P2N2]Ta=CH2(Me), with the elimination of methane. The X-ray solid-state molecular structure of [P2N2]Ta=CH2(Me) is intermediate between octahedral and trigonal-prismatic geometry. Variable-temperature NMR studies demonstrate that the double-bonded methylidene moiety rotates with a barrier of 33.5 +/- 0.6 kJ/mol, in contrast to the larger barrier estimated for the previously characterized 18-electron complex (eta(5)-C5H5)(2)Ta=CH2(Me). Reaction of [P2N2]TaMe3 with Ph3C+BF4- or PhNMe2H+B(C6F5)(4)(-) produced {[P2N2]TaMe2}+BF4- and {[P2N2]TaMe2}B+(C6F5)(4)(-), respectively. Attempts to deprotonate {[P2N2]TaMe2}(+) did not provide a chemical route to [P2N2]Ta=CH2(Me) and instead generated either [P2N2]TaMe2F or the product of deprotonation of the [P2N2] ligand methylene backbone, Ta(Me-2)[(CHSiMe2NSiMe2CH2P(Ph)CH2SiMe2NSiMe2CH2PPh)], depending on the base and counteranion used.}, keywords = {ABSTRACTION, CATALYSIS, COORDINATION, CRYSTAL-STRUCTURES, DECOMPOSITION, DERIVATIVES, imido, METAL-CARBON BONDS, METHYLENE COMPLEX, REACTIVITY}, isbn = {0276-7333}, url = {://000083033500019}, author = {Fryzuk,Michael D. and Johnson, S. A. and Rettig, S. J.} } @article {4344, title = {alpha-naphthyl phenyl pinacols}, journal = {Acta Crystallographica Section C-Crystal Structure Communications}, volume = {54}, year = {1998}, note = {ISI Document Delivery No.: 116CDTimes Cited: 2Cited Reference Count: 16Part 8}, month = {Aug}, pages = {1148-1151}, type = {Article}, abstract = {Treatment of alpha-naphthyl phenyl ketone with Zn/acetic acid gives racemic alpha-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C34H26O2, but reaction with Mg/MgI2 gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo[7.4.0.0(2,6)]trideca-7,9,11,13 -tetraen-3-ol, C34H26O2 The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures, the OH groups are involved in only weak intermolecular interactions.}, keywords = {BOND LENGTH, REACTIVITY, REARRANGEMENT, SOLID-STATE}, isbn = {0108-2701}, url = {://000075704700047}, author = {Mak, T. C. W. and Patrick, B. O. and Rettig, S. J. and Scheffer, J. R. and Trotter, J. and Ukpabi, P. and Wu, B. M. and Yee, V. C.} } @article {4344, title = {alpha-naphthyl phenyl pinacols}, journal = {Acta Crystallographica Section C-Crystal Structure Communications}, volume = {54}, year = {1998}, note = {ISI Document Delivery No.: 116CDTimes Cited: 2Cited Reference Count: 16Part 8}, month = {Aug}, pages = {1148-1151}, type = {Article}, abstract = {Treatment of alpha-naphthyl phenyl ketone with Zn/acetic acid gives racemic alpha-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C34H26O2, but reaction with Mg/MgI2 gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo[7.4.0.0(2,6)]trideca-7,9,11,13 -tetraen-3-ol, C34H26O2 The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures, the OH groups are involved in only weak intermolecular interactions.}, keywords = {BOND LENGTH, REACTIVITY, REARRANGEMENT, SOLID-STATE}, isbn = {0108-2701}, url = {://000075704700047}, author = {Mak, T. C. W. and Patrick, B. O. and Rettig, S. J. and Scheffer, J. R. and Trotter, J. and Ukpabi, P. and Wu, B. M. and Yee, V. C.} } @article {4407, title = {Metal-based chirality and spin state change in 16-electron CpML2 systems: a computational study of CpW(NO)(PH3)}, journal = {Chemical Communications}, number = {17}, year = {1998}, note = {ISI Document Delivery No.: 116QXTimes Cited: 11Cited Reference Count: 35}, month = {Sep}, pages = {1903-1904}, type = {Article}, abstract = {Density functional theory calculations indicate that CpW(NO)(PH3) possesses a planar triplet ground state, a result with significant implications for the inversion of configuration of 16e, d(6) CpML2 species.}, keywords = {alkane, ALKYL, BOND ACTIVATION, C-H ACTIVATION, EFFECTIVE CORE POTENTIALS, INTERMEDIATE, IRIDIUM(III) COMPLEXES, METHANE, MOLECULAR CALCULATIONS, REACTIVITY}, isbn = {1359-7345}, url = {://000075737000060}, author = {Smith, K. M. and Poli, R. and Legzdins,Peter} } @article {4412, title = {Transition metal azolates from metallocenes. Part 3: Polymeric manganese(II) and nickel(II) pyrazolates; synthesis, characterization, and magnetochemistry}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {76}, number = {8}, year = {1998}, note = {ISI Document Delivery No.: 143VNTimes Cited: 13Cited Reference Count: 37}, month = {Aug}, pages = {1130-1137}, type = {Article}, abstract = {Direct reactions of nickelocene and manganocene with molten pyrazoles in an inert atmosphere or under vacuum have led to the isolation of the following metal pyrazolate compounds: [Ni(4-Xpz)(2)](x) (where X = EI, CI and pz = pyrazolate); [M(4-Xdmpz)(2)](x) (where X = H, CH3, Cl, Br and M = Ni, Mn and dmpz = 3,5-dimethylpyazolate); and [Mn(4-Xpz)(2)(4-XpzH)](x) (where X = Cl, Br and pzH = pyrazole). On the basis of indirect evidence all compounds are considered to have extended chain structures with metal ions linked in chains by double bridging pyrazolates. The two [Ni(4-Xpz)2], compounds are diamagnetic while all others are paramagnetic. Variable temperature magnetic susceptibility studies on the paramagnetic compounds reveal antiferromagnetic coupling between neighbouring metal ions. Analysis of the magnetic data (Hamiltonian of the form II = -2J Sigma S-i S-j) yields values of the exchange coupling constant J of -14 to -17 cm(-1) for the [Ni(4-Xdmpz)(2)](x) compounds, -1.2 to -2.1 cm(-1) for the [Mn(4-Xdmpz)(2)](x) compounds, and -0.41 cm(-1) for the [Mn(4-Xpz)(2)(4-XpzH)](x) compounds.}, keywords = {3, 5-DIMETHYLPYRAZOLATE, ANTIFERROMAGNETIC EXCHANGE, BR, CH3, COMPLEXES, CRYSTAL-STRUCTURE, LIGANDS, MAGNETIC-PROPERTIES, manganese, manganocene, NICKEL, nickelocene, pyrazolates, REACTIVITY}, isbn = {0008-4042}, url = {://000077277900003}, author = {Storr, A. and Summers, D. A. and Thompson, R. C.} } @article {4412, title = {Transition metal azolates from metallocenes. Part 3: Polymeric manganese(II) and nickel(II) pyrazolates; synthesis, characterization, and magnetochemistry}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {76}, number = {8}, year = {1998}, note = {ISI Document Delivery No.: 143VNTimes Cited: 13Cited Reference Count: 37}, month = {Aug}, pages = {1130-1137}, type = {Article}, abstract = {Direct reactions of nickelocene and manganocene with molten pyrazoles in an inert atmosphere or under vacuum have led to the isolation of the following metal pyrazolate compounds: [Ni(4-Xpz)(2)](x) (where X = EI, CI and pz = pyrazolate); [M(4-Xdmpz)(2)](x) (where X = H, CH3, Cl, Br and M = Ni, Mn and dmpz = 3,5-dimethylpyazolate); and [Mn(4-Xpz)(2)(4-XpzH)](x) (where X = Cl, Br and pzH = pyrazole). On the basis of indirect evidence all compounds are considered to have extended chain structures with metal ions linked in chains by double bridging pyrazolates. The two [Ni(4-Xpz)2], compounds are diamagnetic while all others are paramagnetic. Variable temperature magnetic susceptibility studies on the paramagnetic compounds reveal antiferromagnetic coupling between neighbouring metal ions. Analysis of the magnetic data (Hamiltonian of the form II = -2J Sigma S-i S-j) yields values of the exchange coupling constant J of -14 to -17 cm(-1) for the [Ni(4-Xdmpz)(2)](x) compounds, -1.2 to -2.1 cm(-1) for the [Mn(4-Xdmpz)(2)](x) compounds, and -0.41 cm(-1) for the [Mn(4-Xpz)(2)(4-XpzH)](x) compounds.}, keywords = {3, 5-DIMETHYLPYRAZOLATE, ANTIFERROMAGNETIC EXCHANGE, BR, CH3, COMPLEXES, CRYSTAL-STRUCTURE, LIGANDS, MAGNETIC-PROPERTIES, manganese, manganocene, NICKEL, nickelocene, pyrazolates, REACTIVITY}, isbn = {0008-4042}, url = {://000077277900003}, author = {Storr, A. and Summers, D. A. and Thompson, R. C.} } @article {4340, title = {Triply-bridged diruthenium(II) 1,4-bis(diphenylphosphino)butane (dppb) and (R)-2,2 {\textquoteright}-bis(diphenylphosphino)-1,1 {\textquoteright}-binaphthyl (binap) complexes, including structural characterisation of [(dppb)ClRu(mu-D2O)-(mu-Cl)(2)RuCl(dppb)], [(eta(2)-H-2)(dppb)Ru(m}, journal = {Inorganica Chimica Acta}, volume = {270}, number = {1-2}, year = {1998}, note = {ISI Document Delivery No.: ZD760Times Cited: 31Cited Reference Count: 57}, month = {Apr}, pages = {130-144}, type = {Article}, abstract = {{Several triply-bridged diruthenium(II)(1,4-bis(diphenylphosphino)butane) complexes were synthesised and characterised by elemental analysis, UV-Vis, NMR and IR spectroscopies, The solid-state structures of [(dppb)ClRu(mu-D2O)(mu-Cl)(2)RuCl(dppb)] (1), [(eta(2)-H-2) (dppb)Ru(mu-Cl)(3)RuCl(dppb)] (2) and [TMP][(dppb)ClRu(mu-Cl)(3)RuCl(dppb)] (3) were established by X-ray crystallographic analyses (TMP=1,1,3-trimethyl-2,3-dihydroperimidinium; dppb = Ph2P(CH2)(4)PPh2). Crystals of 1.1.5C(6)D(6), 2.1.5C(7)D(8) and 3.2Me(2)CO.2H(2)O are all monoclinic, space groups P2(1)/c, P2(1)/n and C2/c, respectively, with Z=4: a=16.8681(6)}, keywords = {ASYMMETRIC HYDROGENATION, catalytic activity, crystal structures, CRYSTAL-STRUCTURE, DEHYDROGENATION, DINUCLEAR, diphosphine complexes, GENERAL-SYNTHESIS, LIGANDS, PHOSPHINE COMPLEXES, REACTIVITY, ruthenium complexes, triply-bridged complexes}, isbn = {0020-1693}, url = {://000072720900018}, author = {Macfarlane, K. S. and Thorburn, I. S. and Cyr, P. W. and Chau, Deky and Rettig, S. J. and James, Brian R.} } @article {3933, title = {Mechanistic aspects of the oxidation of phosphines and related substrates by trans-Ru-VI(TMP)(O)(2); TMP equals dianion of 5,10,15,20-tetramesitylporphyrin}, journal = {Journal of Molecular Catalysis a-Chemical}, volume = {117}, number = {1-3}, year = {1997}, note = {ISI Document Delivery No.: WN736Times Cited: 11Cited Reference Count: 34Proceedings of the 6th International Symposium on the Activation of Dioxygen and Homogeneous Catalytic OxidationAPR 14-19, 1996NOORDWIJKERHOUT, NETHERLANDSRoyal Netherlands Chem Soc}, month = {Mar}, pages = {91-102}, type = {Proceedings Paper}, abstract = {The stoichiometric oxidations of some Pt (p-X-C6H4)(3) compounds (X=OMe, Me, H, F, Cl and CF3), AsPh(3) and SbPh(3) by trans-Ru-VI(TMP)(O)(2) (1) in benzene solution generate the corresponding oxides and Ru-II(TMP)(L) species (L=P(p-X-C6H4)(3), AsPh(3), SbPh(3)). Stopped-flow kinetic data are consistent with a mechanism involving formation (within a k(1) step) of Ru-IV(TMP)(O)(OL) which then reversibly dissociates the OL ligand to generate Ru-IV(TMP)(O); this disproportionates to Ru-VI(TMP)(O)(2) and Ru-II(TMP), which forms Ru-II(TMP)(L). Delta H-1 double dagger values for the phosphine systems vary from 18 to 21 kJ mol(-1), increasing with decreasing electron density at the phosphorus, while Delta S-1 double dagger values become more favorable (-94 to -78 J mol(-1) K-1) with increasing molecular mass of the substituent. Preliminary kinetic data on the O-2-oxidations of the substrates catalyzed by (1) under 1 atm of air are presented.}, keywords = {5-COORDINATE, DINITROGEN COMPLEXES, MECHANISM, models, OXYGEN-TRANSFER, phosphine oxidation, PORPHYRIN COMPLEX, REACTIVITY, ruthenium, RUTHENIUM PORPHYRIN}, isbn = {1381-1169}, url = {://A1997WN73600009}, author = {Cheng, S. Y. S. and James, Brian R.} } @article {4079, title = {Synthesis and X-ray structure of an H2S complex, RuCl2(P-N)(P(p-tolyl)(3))(SH2) (P-N=o-(diphenylphosphino)-N,N-dimethylaniline)}, journal = {Inorganic Chemistry}, volume = {36}, number = {24}, year = {1997}, note = {ISI Document Delivery No.: YH560Times Cited: 24Cited Reference Count: 25}, month = {Nov}, pages = {5426-\&}, type = {Article}, abstract = {The interaction of transition metal complexes with H2S continues to attract attention. Such chemistry is of relevance in the biological sulfur cycle, in the formation of ores, in hydrodesulfurization catalysis, and in the use of H2S as a source of Hz and elemental sulfur (or organosulfur compounds). Literature dealing with these topics is plentiful and can be traced through recent references.(1,2) However, isolation and characterization of metal complexes containing H2S remain challenging,(2,3) as such species tend to undergo oxidative addition reactions to give products with SH ligands or bridged or terminal sulfide,(4) and only recently has an H2S complex been characterized crystallographically.(2) This was the structure reported by Sellmann et al. of the Ru(II)-complex Ru(SH2)(PPh3)({\textquoteright}S-4{\textquoteright}). THF ({\textquoteright}S-4{\textquoteright} = 1,2-bis[(2-mercaptophenyl)thio]ethane(2-)) formed by the reaction of the polymeric complex [Ru(PPh3)({\textquoteright}S-4{\textquoteright})](x) with liquid H2S at -70 degrees C; the reaction with H2S gas at room temperature in THF resulted in a mixture of the bridging sulfide complex [(mu-S-2){Ru(PPh3)({\textquoteright}S-4{\textquoteright})}(2)] and other uncharacterized products depicting the more typical reactivity of H2S with transition metal complexes.(2)}, keywords = {ACTIVATION, hydride, HYDROGEN, LEWIS-ACIDS, MERCAPTO, REACTIVITY, S-H, sulfide, SULFUR-CONTAINING LIGANDS, TRANSITION-METAL COMPLEXES}, isbn = {0020-1669}, url = {://A1997YH56000003}, author = {Mudalige, D. C. and Ma, E. S. and Rettig, S. J. and James, Brian R. and Cullen, W. R.} } @article {4039, title = {Synthesis of novel diamagnetic chromium(II) alkyl complexes}, journal = {Organometallics}, volume = {16}, number = {16}, year = {1997}, note = {ISI Document Delivery No.: XP426Times Cited: 7Cited Reference Count: 38}, month = {Aug}, pages = {3569-3571}, type = {Article}, abstract = {Reaction of Cr(NO)((NPr2)-Pr-i)(3) with PhCO2H leads to Cr(NO)((NPr2)-Pr-i)(O2CPh)(2) (1). The benzoate ligands of 1 may be replaced to form the diamagnetic, structurally-characterized organometallic complexes CpCr(NO)-((NPr2)-Pr-i)(OC(O)Ph) (2), CpCr(NO)((NPr2)-Pr-i)(CH2SiMe3) (3),and Cr(NO)((NPr2)-Pr-i)(CH2SiMe3)(2) (4).}, keywords = {CLEAVAGE, LIGANDS, MOLYBDENUM, ORGANOMETALLIC CHEMISTRY, REACTIVITY, TUNGSTEN}, isbn = {0276-7333}, url = {://A1997XP42600001}, author = {Kuzelka, J. and Legzdins,Peter and Rettig, S. J. and Smith, K. M.} } @article {4143, title = {Thermal alkane C-H bond activation by a tungsten alkylidene complex: The reversal of alpha-hydrogen elimination}, journal = {Journal of the American Chemical Society}, volume = {119}, number = {21}, year = {1997}, note = {ISI Document Delivery No.: XB674Times Cited: 52Cited Reference Count: 36}, month = {May}, pages = {5071-5072}, type = {Article}, keywords = {ABSTRACTION, ADDUCTS, ARYL, BINDING, CHEMISTRY, DERIVATIVES, LIGANDS, METAL-COMPLEXES, REACTIVITY, tantalum}, isbn = {0002-7863}, url = {://A1997XB67400046}, author = {Tran, E. and Legzdins,Peter} } @article {4048, title = {Trapping of Cp*W(NO)(eta(2)-PhC CH), the key intermediate in the C-H activation of alkanes by Cp*W(NO)(CH2SiMe3)(CPh=CH2)}, journal = {Organometallics}, volume = {16}, number = {9}, year = {1997}, note = {ISI Document Delivery No.: WX030Times Cited: 17Cited Reference Count: 21}, month = {Apr}, pages = {1825-1827}, type = {Article}, abstract = {Thermolysis of the vinyl nitrosyl complex Cp*W(NO)(CH2SiMe3)(CPh=CH2) (1) in ethyl acetate or acetonitrile affords the oxa- or azametallacycles Cp*W(NO)(eta(2)-OC(Me)(OEt)CH=CPh) (2) or Cp*W(NO)(eta(3)-HNC(Me)=NC(=CH2)CH=CPh) (3) and Cp*W(NO)(OH)(eta(2)-HN=C(Me)CH=CPh) (4), respectively. Kinetic and mechanistic studies provide compelling evidence for a pathway involving initial rate-limiting unimolecular elimination of SiMe4 from 1 with concomitant formation of Cp*W(NO)(eta(2)-CPh=CH), (A).}, keywords = {HYDROXO COMPLEXES, MILD, REACTIVITY}, isbn = {0276-7333}, url = {://A1997WX03000005}, author = {Legzdins,Peter and Lumb, S. A.} } @article {3918, title = {Unusual ligand-induced reductive elimination in Cp*W(NO)(H)[eta(2)-PPh(2)C(6)H(4)]: A route to the extremely strong pi-donor fragment Cp*W(NO)(PPh(3))}, journal = {Journal of the American Chemical Society}, volume = {119}, number = {5}, year = {1997}, note = {ISI Document Delivery No.: WG232Times Cited: 25Cited Reference Count: 39}, month = {Feb}, pages = {1139-1140}, type = {Article}, keywords = {ACTIVATION, ALKYL, CARBON HYDROGEN-BONDS, COMPLEXES, hydride, ISOCYANIDE, MECHANISM, REACTIVITY, rhenium, TUNGSTEN}, isbn = {0002-7863}, url = {://A1997WG23200042}, author = {Burkey, D. J. and Debad, J. D. and Legzdins,Peter} } @article {3678, title = {The ionic auxiliary concept in solid state organic photochemistry}, journal = {Accounts of Chemical Research}, volume = {29}, number = {4}, year = {1996}, note = {ISI Document Delivery No.: UE738Times Cited: 121Cited Reference Count: 42}, month = {Apr}, pages = {203-209}, type = {Review}, keywords = {ASYMMETRIC INDUCTION, chirality, CRYSTAL, KETONES, PHOTOREARRANGEMENT, REACTIVITY, SALTS, SUPRAMOLECULAR PHOTOCHEMISTRY}, isbn = {0001-4842}, url = {://A1996UE73800006}, author = {Gamlin, J. N. and Jones, R. and Leibovitch, M. and Patrick, B. and Scheffer, J. R. and Trotter, J.} } @article {3678, title = {The ionic auxiliary concept in solid state organic photochemistry}, journal = {Accounts of Chemical Research}, volume = {29}, number = {4}, year = {1996}, note = {ISI Document Delivery No.: UE738Times Cited: 121Cited Reference Count: 42}, month = {Apr}, pages = {203-209}, type = {Review}, keywords = {ASYMMETRIC INDUCTION, chirality, CRYSTAL, KETONES, PHOTOREARRANGEMENT, REACTIVITY, SALTS, SUPRAMOLECULAR PHOTOCHEMISTRY}, isbn = {0001-4842}, url = {://A1996UE73800006}, author = {Gamlin, J. N. and Jones, R. and Leibovitch, M. and Patrick, B. and Scheffer, J. R. and Trotter, J.} } @article {3320, title = {NET AMINE DEALKYLATION AT A DIRUTHENIUM CENTER - DEHYDROGENATION OF A SECONDARY AMINE AND HYDROLYSIS OF A COORDINATED IMINE}, journal = {Inorganic Chemistry}, volume = {34}, number = {10}, year = {1995}, note = {ISI Document Delivery No.: QX706Times Cited: 26Cited Reference Count: 36}, month = {May}, pages = {2557-2561}, type = {Article}, abstract = {Reaction of excess benzylamine with Ru2Cl4(dppb)(2) (1) or RuCl2(dppb)(PPh(3)) (2) under Ar or with Ru2Cl5(dppb)(2) (3) under H-2 or in air generates RuCl2(dppb)(NH(2)CH(2)Ph)(2) [dppb = 1,4-bis(diphenylphosphino)butane, Ph(2)P(CH2)(4)PPh(2)]. Use of 1 equiv of amine per [Ru(II)](2) gives dinuclear Ru2Cl4(dppb)(2)(NH(2)CH(2)Ph) (4a) as a mixture of isomers. The corresponding reactions with dibenzylamine yield only dinuclear products: either Ru2Cl4(dppb)(2)[NH(CH(2)Ph)(2)] (4b), for reactions under H-2, or a mixture of this species and the dealkylation product 4a. The mechanism proposed for formation of the latter involves dehydrogenation of the secondary amine adduct to Ru2Cl4(dppb)(2)[PhCH(2)N=C(H)Ph], followed by hydrolysis of the coordinated imine. Direct reaction of PhCH(2)N=C(H)Ph with 3 under H-2 permits isolation of solely 4b. The findings are of interest also in context of thermal degradation of tertiary amines and hydrogenation of imines catalyzed by Ru ditertiary phosphine complexes.}, keywords = {ACTIVATION, CATALYSTS, COMPLEXES, CONVERSION, CRYSTAL-STRUCTURE, DIHYDROGEN, PHOSPHINE COMPLEXES, PORPHYRIN, REACTIVITY, ruthenium complexes, TERTIARY-AMINES}, isbn = {0020-1669}, url = {://A1995QX70600012}, author = {Fogg, D. E. and James, Brian R.} } @article {3472, title = {SYNTHESIS AND CHARACTERIZATION OF (OCTAETHYLPORPHYRINATO)RUTHENIUM(II) AND (OCTAETHYLPORPHYRINATO)RUTHENIUM(III) COMPLEXES WITH THIOETHER, SULFOXIDE, AND BENZOATE AXIAL LIGANDS}, journal = {Inorganic Chemistry}, volume = {34}, number = {13}, year = {1995}, note = {ISI Document Delivery No.: RF414Times Cited: 16Cited Reference Count: 58}, month = {Jun}, pages = {3477-3484}, type = {Article}, abstract = {{Complexes in the series Ru(OEP)(RR{\textquoteright}S)(2) and Ru(OEP)(RR{\textquoteright}SO)(2) (where OEP = the dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin}, keywords = {AEROBIC EPOXIDATION, CHEMISTRY, CRYSTAL, ELECTRON-TRANSFER, EXTRAPLANAR LIGANDS, OXIDATION, REACTIVITY, redox properties, RUTHENIUM PORPHYRIN DIMERS, SYSTEM}, isbn = {0020-1669}, url = {://A1995RF41400016}, author = {Pacheco, A. and James, Brian R. and Rettig, S. J.} } @article {2986, title = {BIS(ALKOXY)RUTHENIUM(IV) PORPHYRIN COMPLEXES AND AEROBIC OXIDATION OF ALCOHOLS}, journal = {Journal of the Chemical Society-Chemical Communications}, number = {23}, year = {1994}, note = {ISI Document Delivery No.: PW348Times Cited: 25Cited Reference Count: 14}, month = {Dec}, pages = {2669-2670}, type = {Article}, abstract = {The complex trans-Ru-VI(tmp)(O)(2) (tmp = dianion of 5,10,15,20-tetramesitylporphyrin) oxidizes species, of which the bis(isopropoxy) complex has been characterized crystallographically.}, keywords = {CRYSTAL, EPOXIDATION, REACTIVITY, RUTHENIUM OXO COMPLEXES}, isbn = {0022-4936}, url = {://A1994PW34800008}, author = {Cheng, S. Y. S. and Rajapakse, N. and Rettig, S. J. and James, Brian R.} } @article {3069, title = {GAS-PHASE ION CHEMISTRY OF (ETA(6)-C-C7H8)CR(CO)(3) BY FT-ICR SPECTROSCOPY - BETA-HYDRIDE TRANSFER IN ORGANOMETALLIC IONS}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {10}, year = {1994}, note = {ISI Document Delivery No.: NM988Times Cited: 4Cited Reference Count: 65}, month = {May}, pages = {4449-4454}, type = {Article}, abstract = {The gas-phase ion chemistry of eta(6)-cycloheptatriene chromium tricarbonyl was studied by Fourier transform ion cyclotron resonance spectroscopy. The well-known trend that fragment-ion reactivity toward the parent neutral increases with increasing electron deficiency on the metal atom was, in general, observed. However, the reactivity of the fragment ions from (eta(6)-c-C7H8)Cr(CO)(3) shows the order Cr+ > C5H6Cr+ > C7H8Cr+ approximate to C7H8Cr(CO)(+) > C7H8Cr(CO)(2)(+) > C7H8Cr(CO)(3)(+), in which C7H8Cr+ has an anomalously low reactivity. Similarly, the secondary ion-molecule product ion, (C7H8Cr)(2)(+), has an anomalously low reactivity when compared with that of (C7H8Cr)(2)(CO)(3)(+). A more quantitative analysis indicates that the ions C7H8Cr+, C7H8Cr2(CO)(+) and C7H8Cr2(CO)(2)(+) are less reactive than expected. All of these low reactivities can be explained by a beta-hydride shift from the cycloheptatriene ring to the chromium atom that converts the cycloheptatriene ligand into an aromatic tropylium ligand. The coordination hapticity to chromium changes from eta(6) to eta(7) + eta(1) and the electron deficiency of chromium drops by 2. Similarly, the reactivity of the fragment ion C5H6Cr+ implies it has a hydrido-pi-cyclopentadienyl structure. An additional driving force for these rearrangements appears to be the aromatization of the seven-membered cycloheptatriene ring to a tropylium ring and the aromatization of the five-membered cyclopentadiene ring to a cyclopentadienyl ring, as the fragment and secondary ion reactivity orders are normal in the otherwise analogous benzene chromium tricarbonyl and cyclopentadienyl vanadium tetracarbonyl systems. These latter systems have no possible corresponding aromatization reaction. Ions that have low reactivity and have metal-hydrogen bonds react with deuterium-labeled methanol to eliminate a molecule of molecular hydrogen in which one hydrogen atom comes from the hydroxyl group of methanol and the other hydrogen atom comes from the organometallic ion. In contrast, ions that have normal reactivity and do not have metal-hydrogen bonds give methanol adduct products when reacted with methanol.}, keywords = {CARBONYL, CLUSTER FRAGMENTS, CYCLOTRON RESONANCE SPECTROSCOPY, FE+, INSERTION, MASS-SPECTROMETRY, MOLECULE REACTIONS, PRIMARY AMIDE COMPLEXES, REACTIVITY, SYSTEMS, TRANSITION-METAL IONS}, isbn = {0002-7863}, url = {://A1994NM98800037}, author = {Kan, Z. Y. and Taylor, S. M. and Comisarow, M. B.} } @article {2967, title = {AN IONIC HEAVY-ATOM EFFECT IN THE SOLID-STATE PHOTOCHEMISTRY OF A BETA,GAMMA-UNSATURATED KETONE}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {22}, year = {1994}, note = {ISI Document Delivery No.: PP754Times Cited: 13Cited Reference Count: 17}, month = {Nov}, pages = {10322-10323}, type = {Note}, keywords = {REACTIVITY, zeolites}, isbn = {0002-7863}, url = {://A1994PP75400071}, author = {Borecka, B. and Gudmundsdottir, A. D. and Olovsson, G. and Ramamurthy, V. and Scheffer, J. R. and Trotter, J.} } @article {2967, title = {AN IONIC HEAVY-ATOM EFFECT IN THE SOLID-STATE PHOTOCHEMISTRY OF A BETA,GAMMA-UNSATURATED KETONE}, journal = {Journal of the American Chemical Society}, volume = {116}, number = {22}, year = {1994}, note = {ISI Document Delivery No.: PP754Times Cited: 13Cited Reference Count: 17}, month = {Nov}, pages = {10322-10323}, type = {Note}, keywords = {REACTIVITY, zeolites}, isbn = {0002-7863}, url = {://A1994PP75400071}, author = {Borecka, B. and Gudmundsdottir, A. D. and Olovsson, G. and Ramamurthy, V. and Scheffer, J. R. and Trotter, J.} } @article {2951, title = {SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF (NEOPENTYL)(OCTAETHYLPORPHYRINATO)RUTHENIUM COMPLEXES, INCLUDING [RU(OEP)NP]2(MU-LI)2}, journal = {Organometallics}, volume = {13}, number = {7}, year = {1994}, note = {ISI Document Delivery No.: NW037Times Cited: 21Cited Reference Count: 26}, month = {Jul}, pages = {2542-2544}, type = {Note}, abstract = {Reaction of neopentyllithium (LiNp) with the octaethylporphyrin complex Ru(OEP)Cl2 yields Ru-(OEP)Np (1), which can be treated with further LiNp to give [Ru(OEP)Np]2(mu-Li)2 (2). The structures of 1 (the first for an iron-group metalloporphyrin alkyl) and the more remarkable 2, revealing two Li atoms sandwiched between metalloporphyrin moieties, are determined.}, keywords = {CHEMISTRY, CRYSTAL-STRUCTURE, DIMERS, lithium, OXIDATION, REACTIVITY, REDOX, TETRAVALENT RUTHENIUM PORPHYRIN}, isbn = {0276-7333}, url = {://A1994NW03700002}, author = {Alexander, C. S. and Rettig, S. J. and James, Brian R.} } @article {2730, title = {INSERTIONS OF HETEROCUMULENES INTO THE M-C SIGMA-BONDS OF CP-ASTERISK-M(NO)(ARYL)2 (M=MO, W) COMPLEXES}, journal = {Organometallics}, volume = {12}, number = {10}, year = {1993}, note = {ISI Document Delivery No.: MC322Times Cited: 14Cited Reference Count: 32}, month = {Oct}, pages = {4234-4240}, type = {Note}, abstract = {{Treatment of the 16-valence-electron complexes Cp*M(NO)(aryl)2 (Cp* = eta5-C5Me5; M = Mo, W; aryl = phenyl (Ph), p-tolyl) with the heterocumulenes carbon disulfide, p-tolyl isocyanate, and carbon dioxide leads to the eta2-thiocarboxylate, eta2-amide-, and eta2-carboxylate-containing complexes, respectively, in 10-65\% isolated yields. Furthermore, Cp* W(NO) (eta2-S2C-Ph)(Ph) (1) reacts with trimethylphosphine to form Cp*W(NO)(eta2-S2C(PMe3)Ph)(Ph) (10), which contains a zwitterionic phosphonium betaine ligand. The solid-state molecular structure of 10-CH2Cl2 has been established by a single-crystal X-ray crystallographic analysis. Crystal data for Cp*W(NO)(eta2-S2C(PMe3)Ph)(Ph). CH2Cl2: monoclinic}, keywords = {ALKYL, CARBON BONDS, CO2, H-BONDS, ORGANOMETALLIC NITROSYL CHEMISTRY, REACTIVITY, TUNGSTEN, WATER, X-ray structure}, isbn = {0276-7333}, url = {://A1993MC32200074}, author = {Brouwer, E. B. and Legzdins,Peter and Rettig, S. J. and Ross, K. J.} } @article {2773, title = {PREPARATION AND CHARACTERIZATION OF THE OSMIUM CLUSTER COMPLEXES H2OS3(CO)8L(ETFCPCME) (L=CO OR PET2FC) AND H2OS3(CO)8[(ETA-C5H3PET2)FE(ETA-C5H4)]}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {71}, number = {3}, year = {1993}, note = {ISI Document Delivery No.: KU982Times Cited: 4Cited Reference Count: 35}, month = {Mar}, pages = {399-409}, type = {Article}, abstract = {{Thermolysis of Os3(CO)11](PEt2Fc) (Fc = (eta-C5H4)Fe(eta-C5H5)) in octane for 8 h affords H2Os3(CO)9(EtFcPCMe), 10, and H2Os3(CO)8[(eta-C5H3PEt2)Fe(eta-C5H4)], 9e, in 15 and 65\% yield, respectively. Heating Os3(CO),2 and PEt2Fc in 1:2 molar ratio in xylene for 10 h gives two isomers of H2Os3(CO)8(PEt2Fc)(EtFcPCMe), 11, in about 40\% yield. Two crystalline modifications of the complex 9e have been obtained from the same solvent: 9eA, triclinic}, keywords = {BENZYNE, BOND, CHEMISTRY, COMPOUND, COORDINATION, LIGANDS, MODE, RAY CRYSTAL-STRUCTURES, REACTIVITY, TRIOSMIUM CLUSTERS}, isbn = {0008-4042}, url = {://A1993KU98200020}, author = {Cullen, W. R. and Rettig, S. J. and Zheng, T. C.} } @article {2868, title = {RHENIUM(V) AND TECHNETIUM(V) COMPLEXES OF BIDENTATE (0, 0) MONOBASIC 3-OXY-4-PYRONATO AND -4-PYRIDINONATO LIGANDS - X-RAY STRUCTURES OF CIS-BROMOBIS(3-METHYL-2-OXY-4-PYRONATO)OXORHENIUM(V), TETRA-N-BUTYLAMMONIUM TRIBROMO(3-METHYL-2-OXY-4-PYRONATO)OXORHENA}, journal = {Inorganic Chemistry}, volume = {32}, number = {21}, year = {1993}, note = {ISI Document Delivery No.: MC686Times Cited: 27Cited Reference Count: 39}, month = {Oct}, pages = {4491-4497}, type = {Article}, abstract = {{A series of technetium(V) and rhenium(V) complexes of the form [MOXL2], where L is a bidentate (0, 0) monobasic ligand, 2-methyl-3-oxy-4-pyronate (maltolate, ma-) or 1,2-dimethyl-3-oxy-4-pyridinonate (dpp-), and X is a halo ligand}, keywords = {3-HYDROXY-4-PYRIDINONES, aluminum, CHEMISTRY, CRYSTAL-STRUCTURE, MALTOL, MATRIX, NUCLEAR-MEDICINE, RADIOPHARMACEUTICALS, REACTIVITY, SCHIFF-BASES}, isbn = {0020-1669}, url = {://A1993MC68600005}, author = {Luo, H. Y. and Rettig, S. J. and Orvig, Chris} } @article {4547, title = {SYNTHESIS, STRUCTURE AND HYDROGENATION OF ETA-3-BENZYL DIPHOSPHINE COMPLEXES OF RHODIUM AND IRIDIUM}, journal = {Journal of Organometallic Chemistry}, volume = {445}, number = {1-2}, year = {1993}, note = {ISI Document Delivery No.: KR221Times Cited: 30Cited Reference Count: 39}, month = {Feb}, pages = {245-256}, type = {Article}, abstract = {{The preparation of(COD)Rh(eta3-CH2Ph) is described starting from [(COD)Rh]2(mu-Cl)2 by the addition of either Zn(CH2Ph), or Mg(CH2Ph)2(THF)2. The addition of the bulky chelating diphosphines tBu2P(CH2)3PtBu2, iPr2P(CH2)3PiPr2, iPr2P(CH2)2PiPr2, iPr2PCH2PiPr2 and Cy2PCH2PCy2 to (COD)Rh(eta3-CH2Ph) yields the coordinatively unsaturated, four-coordinate rhodium complexes of the form P2Rh(eta3-CH2Ph). Iridium complexes of the form P2Ir(eta3-CH2Ph)(where P2 = tBu2P(CH2)3PtBu, and iPr2P(CH2)3PiPr2) can be prepared from [P2Ir]2(mu-Cl), and Zn(CH2Ph)2 or Mg(CHPh)2(THF)2. Reaction of the benzyl complexes with H-2 (1 atM) yields binuclear hydride derivatives of varying composition depending on the chelate ring size of the coordinated diphosphine. For the diphosphines with only a single methylene in the backbone, binuclear hexahydride complexes are formed in which the diphosphine is binucleating. The X-ray structure of {iPr2P(CH22)3PiPr2}Rh(eta3-CH2Ph) shows a square planar geometry about rhodium with alternating single and double bonds in the eta3-coordinated benzyl fragment. Crystals of (1,3-bis(diiso-propylphosphino)propane}rhodium(eta3-benzyl) are monoclinic}, keywords = {BINUCLEAR, BRIDGING ALKENYL, CATALYTIC-HYDROGENATION, CHEMISTRY, DIHYDROGEN, Hydrides, OXIDATIVE-ADDITION, RAY CRYSTAL-STRUCTURE, REACTIVITY, RHRE(CO)4(PH2PCH2PPH2)2}, isbn = {0022-328X}, url = {://A1993KR22100035}, author = {Fryzuk,Michael D. and McConville, D. H. and Rettig, S. J.} } @article {7271, title = {CRYSTAL TO MOLECULAR CHIRALITY TRANSFER - SUPRAMOLECULAR PHOTOCHEMISTRY OF CRYSTALLINE CARBOXYLATE SALTS}, journal = {Tetrahedron Letters}, volume = {33}, number = {38}, year = {1992}, note = {ISI Document Delivery No.: JN767Times Cited: 25Cited Reference Count: 15}, month = {Sep}, pages = {5481-5484}, type = {Article}, abstract = {Solid state irradiation of a salt formed between a prochiral, photochemically reactive carboxylic acid and a non-absorbing, optically active amine is shown to lead to an optically active Norrish type II photoproduct whose optical purity depends on the dimorphic crystalline modification photolyzed.}, keywords = {ASYMMETRIC INDUCTION, REACTIVITY, SOLID-STATE PHOTOCHEMISTRY}, isbn = {0040-4039}, url = {://A1992JN76700003}, author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yang, J.} } @article {7271, title = {CRYSTAL TO MOLECULAR CHIRALITY TRANSFER - SUPRAMOLECULAR PHOTOCHEMISTRY OF CRYSTALLINE CARBOXYLATE SALTS}, journal = {Tetrahedron Letters}, volume = {33}, number = {38}, year = {1992}, note = {ISI Document Delivery No.: JN767Times Cited: 25Cited Reference Count: 15}, month = {Sep}, pages = {5481-5484}, type = {Article}, abstract = {Solid state irradiation of a salt formed between a prochiral, photochemically reactive carboxylic acid and a non-absorbing, optically active amine is shown to lead to an optically active Norrish type II photoproduct whose optical purity depends on the dimorphic crystalline modification photolyzed.}, keywords = {ASYMMETRIC INDUCTION, REACTIVITY, SOLID-STATE PHOTOCHEMISTRY}, isbn = {0040-4039}, url = {://A1992JN76700003}, author = {Jones, R. and Scheffer, J. R. and Trotter, J. and Yang, J.} } @article {7308, title = {CRYSTALLOGRAPHIC DETERMINATION OF THE PREFERRED GEOMETRY FOR INTRAMOLECULAR HYDROGEN-ATOM ABSTRACTION IN 1,8-CYCLOHEXADECANEDIONE}, journal = {Molecular Crystals and Liquid Crystals}, volume = {219}, year = {1992}, note = {ISI Document Delivery No.: JD451Times Cited: 6Cited Reference Count: 2410TH INTERNATIONAL CONF ON THE CHEMISTRY OF THE ORGANIC SOLID STATE ( ICCOSS 10 )JUL 07-12, 1991VANCOUVER, CANADACHEM INST CANADA, NAT SCI \& ENGN RES COUNCIL CANADA, PETR RES FUND, UNIV BRIT COLUMBIA, BRUKER SPECTROSPIN CANADA, CHEMAGNETICS, DOTY SCI, GORDON \& BREACH SCI PUBL}, pages = {17-28}, type = {Proceedings Paper}, keywords = {CRYSTAL STRUCTURE-REACTIVITY, HYDROGEN ABSTRACTION GEOMETRY, II REACTIONS, MACROCYCLIC DIKETONE, MOLECULAR MECHANICS METHODOLOGY, NORRISH TYPE-II REACTION, PHOTOCHEMISTRY, REACTIVITY, RELATIONSHIPS, SOLID STATE ORGANIC PHOTOCHEMISTRY, STATE, TRANSFERS, TRANSITION STRUCTURES}, isbn = {0140-6566}, url = {://A1992JD45100002}, author = {Lewis, T. J. and Rettig, S. J. and Scheffer, J. R. and Trotter, J.} } @article {7308, title = {CRYSTALLOGRAPHIC DETERMINATION OF THE PREFERRED GEOMETRY FOR INTRAMOLECULAR HYDROGEN-ATOM ABSTRACTION IN 1,8-CYCLOHEXADECANEDIONE}, journal = {Molecular Crystals and Liquid Crystals}, volume = {219}, year = {1992}, note = {ISI Document Delivery No.: JD451Times Cited: 6Cited Reference Count: 2410TH INTERNATIONAL CONF ON THE CHEMISTRY OF THE ORGANIC SOLID STATE ( ICCOSS 10 )JUL 07-12, 1991VANCOUVER, CANADACHEM INST CANADA, NAT SCI \& ENGN RES COUNCIL CANADA, PETR RES FUND, UNIV BRIT COLUMBIA, BRUKER SPECTROSPIN CANADA, CHEMAGNETICS, DOTY SCI, GORDON \& BREACH SCI PUBL}, pages = {17-28}, type = {Proceedings Paper}, keywords = {CRYSTAL STRUCTURE-REACTIVITY, HYDROGEN ABSTRACTION GEOMETRY, II REACTIONS, MACROCYCLIC DIKETONE, MOLECULAR MECHANICS METHODOLOGY, NORRISH TYPE-II REACTION, PHOTOCHEMISTRY, REACTIVITY, RELATIONSHIPS, SOLID STATE ORGANIC PHOTOCHEMISTRY, STATE, TRANSFERS, TRANSITION STRUCTURES}, isbn = {0140-6566}, url = {://A1992JD45100002}, author = {Lewis, T. J. and Rettig, S. J. and Scheffer, J. R. and Trotter, J.} } @article {7253, title = {MOLECULAR DIHYDROGEN AND HYDRIDO DERIVATIVES OF RUTHENIUM(II) COMPLEXES CONTAINING CHELATING FERROCENYL-BASED TERTIARY PHOSPHINE AMINE LIGANDS AND OR MONODENTATE TERTIARY PHOSPHINE-LIGANDS}, journal = {Inorganic Chemistry}, volume = {31}, number = {26}, year = {1992}, note = {ISI Document Delivery No.: KE754Times Cited: 34Cited Reference Count: 60}, month = {Dec}, pages = {5509-5520}, type = {Article}, abstract = {{Reactions of complexes of the type RuCl2(PPh3)(P-N) with H2 are reported, where P-N represents the chelating ferrocene-based ligands (eta-C5H5)Fe(etaC5H3(CHMeNMe2)PR2-1,2) with R = i-Pr (the isoPFA ligand) or Ph (the PPFA ligand). Depending on the solvent(s) used, and absence or presence of added base, RuCl2(PPh3)(isoPFA) (2b) generates the dinuclear eta2-H2 complexes L2(eta2-H2)Ru(eta-Cl)2(eta-H)Ru(H)(PPh3)2 where L2 = isoPFA (complex 3) or L2 = (PPh3)2 (complex 4). n-Butanol solutions of RuCl2(PPh3)(PPFA) (2a) under H-2 also yield 4, as well as Ru(H)Cl2(PPh3)(PPFA.H)(BuOH), a zwitterionic species containing a protonated amine moiety stabilized by coordinated n-BuOH, which is a likely intermediate in heterolytic cleavage of the H-2: the complex RuH(Cl)-PPh3)(isoPFA) (5), together with a hydrido carbonyl species, is isolated from methanol solutions of 2b. Complexes 2b, 3, 4, and 5 are characterized by X-ray crystallography; the mononuclear complexes 2b and 5 are orthorhombic with space groups F2dd and P2(2)2(1)2(1), respectively. For 2b}, keywords = {BOND, CARBONYL, D6 COMPLEXES, ETA-2-DIHYDROGEN, EXCHANGE, H-H, HYDROGEN COMPLEXES, palladium, REACTIVITY, TRANSITION-METALS}, isbn = {0020-1669}, url = {://A1992KE75400029}, author = {Hampton, Crsm and Butler, I. R. and Cullen, W. R. and James, Brian R. and Charland, J. P. and Simpson, J.} } @article {7235, title = {MONONUCLEAR AND DINUCLEAR RHODIUM CARBONYL SPECIES CONTAINING MONODENTATE OR BRIDGING 1,3-BIS(DIPHENYLPHOSPHINO)PROPANE}, journal = {Gazzetta Chimica Italiana}, volume = {122}, number = {8}, year = {1992}, note = {ISI Document Delivery No.: JW695Times Cited: 2Cited Reference Count: 50}, month = {Aug}, pages = {329-334}, type = {Article}, abstract = {The interaction of [Rh(CO)(dpp)]2(mu-CO)2 with H-2 in CH2Cl2 in the presence of varying amounts of dpp leads mainly to catalytically important species which include Rh(H)(CO)(dpp)(dpp*) and [RhH(CO)(dpp)]2(mu-dpp), these being formed also by treating RhH(dpp)2 with about 2 equivalents of CO; dpp and dpp* = bidentate and monodentate 1,3-bis(diphenylphosphino)propane, respectively. Mechanistic pathways involving a detected RhH(CO)2(dpp) and non-detected <> species are suggested.}, keywords = {ASYMMETRIC HYDROGENATION, CATALYSIS, CATALYTIC-HYDROGENATION, COMPLEXES, DIHYDROGEN, homogeneous, HYDROACYLATION, HYDROFORMYLATION, INSERTION, MONOXIDE, REACTIVITY}, isbn = {0016-5603}, url = {://A1992JW69500009}, author = {Fung, D. C. M. and James, Brian R.} } @article {7303, title = {ORGANOMETALLIC NITROSYL CHEM .52. A UNIQUE MU-ETA-1-ETA-2-NO LIGAND IN A BIMETALLIC ALKYLIDENE NITROSYL COMPLEX OF MOLYBDENUM}, journal = {Journal of the American Chemical Society}, volume = {114}, number = {17}, year = {1992}, note = {ISI Document Delivery No.: JH996Times Cited: 15Cited Reference Count: 18}, month = {Aug}, pages = {6922-6923}, type = {Note}, keywords = {ABSTRACTION, CHEMISTRY, COMPOUND, DOUBLE-BOND, MOLECULAR-STRUCTURE, REACTIVITY, TETRANITROSYL, TUNGSTEN}, isbn = {0002-7863}, url = {://A1992JH99600051}, author = {Legzdins,Peter and Rettig, S. J. and Veltheer, J. E.} } @article {7234, title = {REACTIONS OF NITRILES WITH BINUCLEAR RHODIUM HYDRIDES - THE STEPWISE REDUCTION OF A CARBON NITROGEN TRIPLE BOND AT 2 METAL CENTERS}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {70}, number = {9}, year = {1992}, note = {ISI Document Delivery No.: JW978Times Cited: 14Cited Reference Count: 29}, month = {Sep}, pages = {2381-2389}, type = {Article}, abstract = {{The reaction of simple nitriles, R{\textquoteright}CN (R{\textquoteright} = CH3, Ph, o-tol) with the electron-rich binuclear rhodium hydride derivatives [(R2PCH2CH2PR2)Rh]2(mu-H)2 (R = Pr(i): [(dippe) Rh]2(mu-H)2: R = OPri: [(dipope)Rh]2(mu-H)2) results in the formation of alkylideneimido derivatives [(R2PCH2CH2PR2)Rh]2(mu-H)(mu-N=CHR{\textquoteright}), apparently by insertion of the nitrile moiety into a bridging hydride bond: this was confirmed by the reaction of nitriles with the dideuteride [(dippe)Rh]2(mu-D)2, which resulted in the formation of [(dippe)Rh]2(mu-D)(mu-N=CHR{\textquoteright}). Further reduction can take place by addition of H-2 to generate the corresponding amide hydride derivatives [(dippe)Rh]2(mu-H)(mu-NHCH2R{\textquoteright}); this represents an overall stoichiometric reduction of a nitrile to a coordinated amide at a binuclear centre. These same amido-hydride complexes can be accessed by addition of amine to the starting binuclear rhodium hydride derivatives. The X-ray structure of [(Pri2PCH2CH2PPri2)Rh]2(mu-H)(mu-N=CHCH3) was undertaken to confirm the structure of these particular intermediates. Crystals of this material are monoclinic}, keywords = {ACIMIDOYL, CATALYTIC-HYDROGENATION, cluster complexes, CRYSTAL, LIGANDS, REACTIVITY}, isbn = {0008-4042}, url = {://A1992JW97800008}, author = {Fryzuk,Michael D. and Piers, W. E. and Rettig, S. J.} } @article {7071, title = {THE CHEMICAL CONSEQUENCES OF CONFORMATIONAL POLYMORPHISM - THE PHASE-TRANSITION-DEPENDENT PHOTOCHEMISTRY OF CRYSTALLINE 1,14-CYCLOHEXACOSANEDIONE}, journal = {Journal of the American Chemical Society}, volume = {113}, number = {21}, year = {1991}, note = {ISI Document Delivery No.: GJ647Times Cited: 11Cited Reference Count: 17}, month = {Oct}, pages = {8180-8181}, type = {Note}, keywords = {REACTIVITY}, isbn = {0002-7863}, url = {://A1991GJ64700061}, author = {Lewis, T. J. and Rettig, S. J. and Scheffer, J. R. and Trotter, J.} } @article {7071, title = {THE CHEMICAL CONSEQUENCES OF CONFORMATIONAL POLYMORPHISM - THE PHASE-TRANSITION-DEPENDENT PHOTOCHEMISTRY OF CRYSTALLINE 1,14-CYCLOHEXACOSANEDIONE}, journal = {Journal of the American Chemical Society}, volume = {113}, number = {21}, year = {1991}, note = {ISI Document Delivery No.: GJ647Times Cited: 11Cited Reference Count: 17}, month = {Oct}, pages = {8180-8181}, type = {Note}, keywords = {REACTIVITY}, isbn = {0002-7863}, url = {://A1991GJ64700061}, author = {Lewis, T. J. and Rettig, S. J. and Scheffer, J. R. and Trotter, J.} } @article {7038, title = {HYDRIDO THIOLATO AND THIOLATO COMPLEXES OF RUTHENIUM(II) CARBONYL PHOSPHINES}, journal = {Inorganic Chemistry}, volume = {30}, number = {24}, year = {1991}, note = {ISI Document Delivery No.: GR813Times Cited: 52Cited Reference Count: 76}, month = {Nov}, pages = {4617-4627}, type = {Article}, abstract = {{Oxidative addition of RSH (R = H, alkyl, aryl) or RSSR (R = aryl) to Ru(CO)2L3 (L = PPh3, 1) yields respectively cct-RuH(SR)(CO)2L2 (type 2) (cct = cis,cis,trans) or cct-Ru(SR)2(CO)2L2 (type 3); a hydrido selenolate species is made similarly using PhSeH. Methods for in situ formation of corresponding mixed bis(thiolate) species are also given. 1 is generally unreactive toward thioethers, although with propylene sulfide cct-Ru(eta-2-S2) (CO)2L2 is produced. Metathesis reactions of cct-RuCl2(CO)2L2 with NaSR salts yield 3 (R = aryl) or, when R = Et, cct-RuCl(SEt)(CO)2L2 or [L(CO)2Ru(mu-2-SEt)2(mu-3-SEt)Na(THF)]2 (4), depending on reaction conditions. The complexes are characterized by IR spectroscopy, H-1, P-31, and, in some cases, C-13 NMR spectroscopy, and for 2g and 3g (R = SC6H4pMe) and 4, X-ray crystallography. All three complexes crystallized in the space group P1BAR. For 2g}, keywords = {CHEMISTRY, DERIVATIVES, MECHANISM, METHYLDISULFIDO-LIGAND, MOLECULAR-STRUCTURE, NUCLEAR MAGNETIC-RESONANCE, OSMIUM, REACTIVITY, TRANSITION-METALS, X-RAY CRYSTAL}, isbn = {0020-1669}, url = {://A1991GR81300031}, author = {Jessop, P. G. and Rettig, S. J. and Lee, C. L. and James, Brian R.} } @article {7073, title = {SYNTHESIS AND CHARACTERIZATION OF A PENTADENTATE SCHIFF-BASE N3O2 LIGAND AND ITS NEUTRAL TECHNETIUM(V) COMPLEX - X-RAY STRUCTURE OF (N,N{\textquoteright}-3-AZAPENTANE-1,5-DIYLBIS(3-(1-IMINOETHYL)-6-METHYL-2H-PYRAN-2,4(3H )-DIONATO)(3-)-O,O{\textquoteright},N,N{\textquoteright},N{\textquoteright}{\textquoteright})OXOTECHNETI}, journal = {Inorganic Chemistry}, volume = {30}, number = {26}, year = {1991}, note = {ISI Document Delivery No.: GX615Times Cited: 19Cited Reference Count: 35}, month = {Dec}, pages = {4915-4919}, type = {Article}, abstract = {{Preparations of a potentially pentadentate ligand, N,N{\textquoteright}-3-azapentane-1,5-diylbis(3-(1-iminoethyl)-6-methyl-2H-pyran-2,4-(3H )-dione) (H3apa), and its neutral technetium(V) complex, [TcO(apa)], are described. The C-13 and H-1 NMR, infrared, optical, and mass spectra of the pentadentate ligand and its technetium(V) complex are reported. The X-ray structure of [TcO(apa)] has been determined. Crystals are orthorhombic, space group Pbca, with a = 12.833 (2) angstrom}, keywords = {2+ CORE, AGENTS, CHEMISTRY, CRYSTAL-STRUCTURE, DONOR-ATOM SET, gallium, OXOTECHNETIUM(V) COMPLEXES, REACTIVITY, RHENIUM(V) OXO-COMPLEXES, S-METHYL DITHIOCARBAZATE}, isbn = {0020-1669}, url = {://A1991GX61500013}, author = {Liu, S. and Rettig, S. J. and Orvig, Chris} } @article {7015, title = {THERMAL AND PHOTOCHEMICAL-TRANSFORMATIONS OF ORGANOIRIDIUM PHOSPHIDE COMPLEXES - MECHANISTIC STUDIES ON CARBON PHOSPHORUS BOND FORMATION TO GENERATE CYCLOMETALATED HYDRIDE COMPLEXES BY ALPHA-HYDRIDE ABSTRACTION}, journal = {Journal of the American Chemical Society}, volume = {113}, number = {23}, year = {1991}, note = {ISI Document Delivery No.: GP037Times Cited: 28Cited Reference Count: 62}, month = {Nov}, pages = {8724-8736}, type = {Article}, abstract = {{The thermal and photolytic transformations of a series of methyliridium(III) phosphide complexes are described. Complexes of the formula Ir(CH3)PR2[N(SiMe2CH2PPh2)2] (R = Ph, Me) rearrange thermally to generate the corresponding cyclometalated derivatives fac-Ir(eta-2-CH2PR2)H[N(SiMe2CH2PPh2)2]; continued thermolysis results in the formation of the iridium(I) phosphine complexes Ir(PMeR2)[N(SiMe2CH2PPh2)2]. Under photolytic conditions the phosphide derivatives rearrange directly to the phosphine complexes with no observable intermediates. The phenylphosphide complex Ir(CH3)PHPh[N-(SiMe2CH2PPh2)2] rearranges directly to the phosphine derivative Ir(PHPhMe)[N(SiMe2CH2PPh2)2] both thermally and photolytically with no observable intermediates. Crystals of lr(CH3)PPh2[N(SiMe2CH2PPh2)2] are monoclinic with a = 13.506 (3) angstrom}, keywords = {ACTIVATION, C-H, CHEMISTRY, CRYSTAL-STRUCTURE, DERIVATIVES, HYDROGEN-BONDS, IRIDIUM, LIGAND, REACTIVITY, REDUCTIVE ELIMINATION}, isbn = {0002-7863}, url = {://A1991GP03700020}, author = {Fryzuk,Michael D. and Joshi, K. and Chadha, R. K. and Rettig, S. J.} } @article {7029, title = {AN UNUSUAL 17-ELECTRON ORGANOMETALLIC RADICAL, CPCR(NO)(PPH3)(CH2SIME3)}, journal = {Journal of the American Chemical Society}, volume = {113}, number = {18}, year = {1991}, note = {ISI Document Delivery No.: GD306Times Cited: 10Cited Reference Count: 18}, month = {Aug}, pages = {7049-7050}, type = {Note}, keywords = {BOND, COMPLEXES, NITROSYL CHEMISTRY, REACTIVITY}, isbn = {0002-7863}, url = {://A1991GD30600060}, author = {Herring, F. G. and Legzdins,Peter and McNeil, W. S. and Shaw, M. J. and Batchelor, R. J. and Einstein, F. W. B.} } @article {6884, title = {ALKYNE AND ALKENE COMPLEXES OF (TETRAMESITYLPORPHYRINATO)RUTHENIUM(II)}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {68}, number = {12}, year = {1990}, note = {ISI Document Delivery No.: EU273Times Cited: 26Cited Reference Count: 21}, month = {Dec}, pages = {2274-2277}, type = {Article}, abstract = {The reactions of benzene or toluene solutions of Ru11(TMP), where TMP is the dianion of 5,10,15,20-tetramesitylporphyrin, with some acetylenes and alkenes are reported. Acetylene yields the isolable [Ru(TMP)]2(mu-C2H2) species; while with phenylacetylene or diphenylacetylene, 1:1 pi-complexes are formed. The pi-complexes Ru(TMP)(C2H4) and Ru(TMP)(C2H4)(i)PrOH.(i)PrOH are isolated from reactions with ethylene, and a similar cyclohexene species is characterized in situ. The findings are relevant to O2-epoxidation of alkenes catalyzed by the trans-Ru(TMP)(O)2 complex.}, keywords = {ALKENE COMPLEXES, ALKYNE COMPLEXES, DINITROGEN COMPLEXES, HYDRIDORHODIUM(III) OCTAETHYLPORPHYRIN, OSMIUM, PORPHYRIN (TETRAMESITYL), PORPHYRIN COMPLEXES, REACTIVITY, RHODIUM(II) OCTAETHYLPORPHYRIN DIMER, ruthenium}, isbn = {0008-4042}, url = {://A1990EU27300026}, author = {Rajapakse, N. and James, Brian R. and Dolphin, D.} }