@article {SOUTHCOTT2022111789, title = {Bis(amido)bis(oxinate)diamine Ligands for theranostic radiometals}, journal = {J. Inorg. Biochem.}, volume = {231}, year = {2022}, month = {03/2022}, pages = {111789. Invited for Special Issue in Memory of Ademir Neves}, abstract = {

With the interest in radiometal-containing diagnostic and therapeutic pharmaceuticals increasing rapidly, appropriate ligands to coordinate completely and stably said radiometals is essential. Reported here are two novel, bis(amido)bis(oxinate)diamine ligands, H2amidohox (2,2\′-(ethane-1,2-diylbis(((8-hydroxyquinolin-2-yl)methyl)azanediyl))diacetamide) and H2amidoC3hox (2,2\′-(propane-1,3-diylbis(((8-hydroxyquinolin-2-yl)methyl)azanediyl))diacetamide), that combine two 8-hydroxyquinoline and amide donor groups and differ by one carbon in their 1,2-ethylenediamine vs. 1,3-diaminopropane backbones, respectively. Both ligands have been thoroughly studied via metal complexation, solution thermodynamics and radiolabeling with three radiometal ions: [nat/64Cu]Cu2+, [nat/111In]In3+, and [nat/203Pb]Pb2+. X-ray crystallography determined the structures of the hexacoordinated Cu2+-ligand complexes, indicating a better fit of Cu2+ to the H2amidohox binding pocket. Concentration dependent radiolabeling with [64Cu]Cu2+ was successfully quantitative as low as 1\ μM with H2amidohox and 10\ μM with H2amidoC3hox within 5\ min at room temperature. However, [64Cu][Cu(amidohox)] maintained higher kinetic inertness against a superoxide dismutase enzyme-challenge assay and ligand challenges compared to the [64Cu][Cu(amidoC3hox)] counterpart. Similarly, H2amidohox had significantly higher radiochemical conversion with both [111In]In3+ (97\% at 1\ μM) and [203Pb]Pb2+ (97\% at 100\ μM) under mild conditions compared to H2amidoC3hox (76\% with [111In]In3+ at 1\ μM and 0\% with [203Pb]Pb2+). By studying non-radioactive and radioactive complexation with both ligands, a comprehensive understanding of the coordination differences between two- and three-carbon diamine backbones is discussed. Overall, the ethylenediamine backbone of H2amidohox proves to be superior in rapid, mild radiolabeling and kinetic inertness towards competing ligands and proteins.

}, keywords = {COORDINATION CHEMISTRY, Theranostics, [In]In [Cu]Cu [Pb]Pb solution thermodynamic studies}, issn = {0162-0134}, doi = {https://doi.org/10.1016/j.jinorgbio.2022.111789}, url = {https://www.sciencedirect.com/science/article/pii/S0162013422000782}, author = {Lily Southcott and Jennifer N. Whetter and Luke Wharton and Brian O. Patrick and Kristof Zarschler and Manja Kubeil and Holger Stephan and Mar{\'\i}a de Guadalupe Jaraquemada-Pel{\'a}ez and Chris Orvig} } @article {2680, title = {N-Heterocyclic Carbene Rhodium Complexes and Their Reactions with H-2 and with CO}, journal = {European Journal of Inorganic Chemistry}, number = {13}, year = {2009}, note = {ISI Document Delivery No.: 447KWTimes Cited: 5Cited Reference Count: 53Yu, Xiao-Yan Sun, Hongsui Patrick, Brian O. James, Brian R.}, month = {May}, pages = {1752-1758}, type = {Article}, abstract = {The NHC-Rh-I complexes [RhCl(COE)(NHC)](2) 1 and 2 [COE = cyclooctene, NHC in 1 = N,N-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) and, in 2, N,N-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes)] react with H-2 in hexane to give the dimeric, mono-carbene dihydrido species [Rh(H)(2)Cl(NHC)](2) (NHC = IPr (3), IMes (4)). In the presence of further NHC, the bis-carbene dihydrido species Rh(H)(2)Cl(NHC)(2) are formed; a crystal structure of the IPr complex 5 is analogous to that of the known IMes analogue. The dihydride-mixed-carbene species Rh(H)(2)Cl(IPr)(IMes) (5a) was also observed but not isolated. A benzene solution of 5 under D-2 slowly generates the corresponding dideuteride. Reactions of the mono-carbenes (1/3, or 2/4) with CO in hexane afford the respective dicarbonyl complexes RhCl(CO)(2)(NHC) [NHC = IPr (6), IMes (7)], while CO reactions with the bis-carbene dihydrides give, respectively, the mono-carbonyl complex RhCl(CO)(IPr)(2) (8) and the known IMes analogue. All the complexes are characterized by elemental analysis, H-1 and C-13{H-1} NMR and IR spectroscopies and, in the case of 5, by X-ray crystallography. The catalytic activities of 5 and the previously reported Rh(H)(2)Cl(IMes)(2) for hydrogenation of COE and 1-octene (and isomerization of the latter) are shown to be poor. ((c) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {14-ELECTRON, Carbene ligands, carbonyl ligands, CATALYTIC-ACTIVITY, COORDINATION CHEMISTRY, H ACTIVATION, Hydrides, HYDROFORMYLATION, HYDROGENATION, iridium complexes, LIGANDS, NHC COMPLEX, NMR, RH(III), rhodium}, isbn = {1434-1948}, url = {://000266191000009}, author = {Yu, X. Y. and Sun, H. S. and Patrick, B. O. and James, Brian R.} } @article {2494, title = {N,O-Chelates of Group 4 Metals: Contrasting the Use of Amidates and Ureates in the Synthesis of Metal Dichlorides}, journal = {European Journal of Inorganic Chemistry}, number = {18}, year = {2009}, note = {ISI Document Delivery No.: 467LNTimes Cited: 5Cited Reference Count: 69Leitch, David C. Beard, J. David Thomson, Robert K. Wright, Vincent A. Patrick, Brian O. Schafer, Laurel L.}, month = {Jun}, pages = {2691-2701}, type = {Article}, abstract = {A series of dichloride complexes of titanium and zirconium with amidate and ureate ancillary ligands have been prepared, Three examples of bis(amidate)dichlorotitanium and zirconium complexes were effectively synthesized through salt metathesis with metal tetrachloride as starting materials. Optimum results were achieved using sodium amidate salts formed from sodium bis(trimethylsilyl)amide and neutral amide proligands, while other methods were ineffective. Use of electron-donating ureate ligands in lieu of amidates enables preparation through alternate routes. Protonolysis of Ti(NMe2)(2)Cl-2 and Zr(NMe2)(2)Cl-2(dme) with urea proligands leads to dichlorobis(ureate) complexes in good yield. Using a tethered bis(ureate) ligand eliminates the fluxional behaviour and coordination isomerism observed for both bis(amidate) and bis(ureate) zirconium complexes. ((C) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {amidate, BIS(AMIDATE) TITANIUM PRECATALYST, CATALYTIC, Chelates, COORDINATION CHEMISTRY, EARLY, GUANIDINATE LIGANDS, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, N, O ligands, OLEFIN POLYMERIZATION, SOLUTION DYNAMICS, STRUCTURAL-CHARACTERIZATION, TITANIUM, TRANSITION-METALS, Ureate, ZIEGLER-NATTA POLYMERIZATION, ZIRCONIUM}, isbn = {1434-1948}, url = {://000267740500015}, author = {Leitch, D. C. and Beard, J. D. and Thomson, R. K. and Wright, V. A. and Patrick, B. O. and Schafer, L. L.} } @article {2679, title = {Template Synthesis of Donor-Functionalized NX-Carbenes (X = P, Si)}, journal = {Organometallics}, volume = {28}, number = {21}, year = {2009}, note = {ISI Document Delivery No.: 511VVTimes Cited: 2Cited Reference Count: 32Yu, Insun Wallis, Christopher J. Patrick, Brian O. Mehrkhodavandi, Parisa}, month = {Nov}, pages = {6370-6373}, type = {Article}, abstract = {Donor-functionalized (phosphino)(amino)- and (silyl)(amino)carbenes are generated via nucleophilic attack at the carbon atom of a coordinated isocyande on a piano-stool iron(II) complex. The template synthesis methodology involves the formation of ylidene complexes, which are reduced to yield the desired carbene complexes. The electronic properties of the resulting carbene complexes are similar and indicate that in the (phosphino)(amino)carbene the phosphine lone pair is not interacting with the carbene carbon and is available for further reactivity.}, keywords = {ALKYL AMINO CARBENES, CATALYSTS, COORDINATION CHEMISTRY, HETEROCYCLIC CARBENES, ISOCYANIDES, LIGANDS, TRANSITION-METALS, TUNGSTEN COMPLEXES}, isbn = {0276-7333}, url = {://000271200300030}, author = {Yu, I. and Wallis, C. J. and Patrick, B. O. and Mehrkhodavandi, Parisa} } @article {1572, title = {Synthesis, reactivity, and DFT studies of tantalum complexes incorporating diamido-N-heterocyclic carbene ligands. Facile endocyclic C-H bond activation}, journal = {Journal of the American Chemical Society}, volume = {128}, number = {38}, year = {2006}, note = {ISI Document Delivery No.: 085OFTimes Cited: 25Cited Reference Count: 73Spencer, Liam P. Beddie, Chad Hall, Michael B. Fryzuk, Michael D.}, month = {Sep}, pages = {12531-12543}, type = {Article}, abstract = {The syntheses of tantalum derivatives with the potentially tridentate diamido-N-heterocyclic carbene (NHC) ligand are described. Aminolysis and alkane elimination reactions with the diamine-NHC ligands, (Ar)[NCN]H-2 (where (Ar)[NCN]H-2 = (ArNHCH2CH2)(2)(C3N2); Ar = Mes, p-Tol), provided complexes with a bidentate amide-amine donor configuration. Attempts to promote coordination of the remaining pendent amine donor were unsuccessful. Metathesis reactions with the dilithiated diamido-NHC ligand ((Ar)[NCN]-Li-2) and various ClxTa(NR{\textquoteright}(2))(5-x) precursors were successful and generated the desired octahedral (Ar)[NCN]TaClx(NR{\textquoteright}(2))(3-x) complexes. Attempts to prepare trialkyl tantalum complexes by this methodology resulted in the formation of an unusual metallaaziridine derivative. DFT calculations on model complexes show that the strained metallaaziridine ring forms because it allows the remaining substituents to adopt preferable bonding positions. The calculations predict that the lowest energy pathway involves a tantalum alkylidene intermediate, which undergoes C-H bond activation R to the amido to form the metallaaziridine moiety. This mechanism was confirmed by examining the distribution of deuterium atoms in an experiment between (Mes)[NCN]Li-2 and Cl2Ta(CD2Ph)(3). The single-crystal X-ray structures of (p-Tol)[NCNH]Ta(NMe2)(4) (3), (Mes)[NCNH]Ta=CHPh(CH2Ph)(2) (4), (p-Tol)[NCN]Ta(NMe2)(3) (7), (Mes)[NCCN]Ta((CH2Bu)-Bu-t)(2) (11), and (Mes)[NCCN]-TaCl((CH2Bu)-Bu-t) (14) are included.}, keywords = {COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EFFECTIVE CORE POTENTIALS, GAUSSIAN-TYPE BASIS, METAL-CARBON BONDS, METHODS, MOLECULAR-ORBITAL, ORGANIC-MOLECULES, SET MODEL CHEMISTRY, STABLE CARBENES, STRUCTURAL-CHARACTERIZATION}, isbn = {0002-7863}, url = {://000240612700055}, author = {Spencer, L. P. and Beddie, C. and Hall, M. B. and Fryzuk,Michael D.} } @article {1143, title = {Platinum(II) and palladium(II) complexes of bisphosphine ligands bearing o-N,N-dimethylanilinyl substituents: A hint of catalytic olefin hydration}, journal = {Inorganic Chemistry}, volume = {44}, number = {9}, year = {2005}, note = {ISI Document Delivery No.: 922CLTimes Cited: 9Cited Reference Count: 55}, month = {May}, pages = {3290-3298}, type = {Article}, abstract = {Platinum(II) and palladium(II) complexes of the potentially hexadentate P,N-donor ligand family Ar2P-X-PAr2 (X = (CH2)(2) [dmape], cyclic-C5H8 [dmapcp]; Ar = o-NN-dimethylanilinyl) are described. In CH2Cl2, the dmape complexes exist as equilibrium mixtures of MCl2(P,P{\textquoteright}-dmape) and [MCl(P, P, N-dmape)]Cl isomers (M = Pd, Pt), governed by Delta H degrees = -19 +/- 4 U mol(-1) and Delta S degrees = -100 +/- 30 J mol(-1) K-1 for M = Pt, and Delta H degrees = -11 +/- 7 U mol-1 and Delta S degrees = -60 +/- 20 J mol-1 K-1 for M = Pd. The water-soluble dmapcp complexes exist solely in the [MCl(P,P{\textquoteright},N-dmapcp)]Cl form, but the free and coordinated anilinyl rings in these complexes are in slow diastereoselective exchange, X-ray crystal structures for MCl2(P,P{\textquoteright}-dmape) (M = Pd, Pt), and the [PdCl(P,P{\textquoteright},N-dmape)](+) and [PtCl-P,P{\textquoteright},N-dmapcp)](+) cations, are presented. Some of the complexes show marginal activity in water for the catalyzed hydration of maleic to malic acid, giving about 6-7\% conversion in 24 h at 100 degrees C and substrate: catalyst loadings of 100:1. Attempts to synthesize a PdCl(P,P{\textquoteright},N-dmapm)(+) species led instead to isolation of [Pd(mu-Cl)(P,P-dmapm)](2)-[PF6](2) (dmapm = Ar2PCH2Ar2).}, keywords = {2-PYRIDYLPHOSPHINE LIGANDS, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, DERIVATIVES, DONOR GROUPS, HYDROGENATION, RHODIUM COMPLEXES, RUTHENIUM(II), TERTIARY PHOSPHINES, WATER-SOLUBLE PHOSPHINES}, isbn = {0020-1669}, url = {://000228813400045}, author = {Jones, N. D. and Meessen, P. and Losehand, U. and Patrick, B. O. and James, Brian R.} } @article {1204, title = {Synthesis and characterization of dual function vanadyl, gallium and indium curcumin complexes for medicinal applications}, journal = {Journal of Inorganic Biochemistry}, volume = {99}, number = {11}, year = {2005}, note = {ISI Document Delivery No.: 984RUTimes Cited: 22Cited Reference Count: 41}, month = {Nov}, pages = {2217-2225}, type = {Article}, abstract = {Novel bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione (curcumin) complexes with the formula, ML3, where M is Ga(III) or In(III), or of the formula, ML2 where M is [Vo](2+), have been synthesized and characterized by mass spectrometry, infrared and absorption spectroscopies, and elemental analysis. A new ligand, bis[4-acetyl-3-hydroxyphenyl]-1,6-heptadiene-3,5-dione (diacetylbisdemethoxycurcumin, DABC) was similarly characterized; an X-ray structure analysis was performed. Vanadyl complexes tested in an acute i.p. testing protocol in STZ-diabetic rats showed a lack of insulin enhancing potential. Vanadyl complexes were, however, more cytotoxic than were the ligands alone in standard MTT (3-[4,5-dimethylthiazole-2-yl]ate, -2.5-diphenyl-tetrazolium bromide) cytotoxicity testing, using mouse lymphoma cells. With the exception of DABC, that was not different from VO(DABC)(2), the complexes were not significantly different from one another, with IC50 values in the 5-10 mu M range. Gallium and indium curcumin complexes had IC50 values in the same 5-10 mu M range; whereas Ga(DAC)(3) and In(DAC)(3) (where DAC = diacetylcurcumin) were much less cytotoxiC (IC50 = 20-30 mu M). Antioxidant capacity was decreased in VO(DAC)(2), Ga(DAC)(3), and In(DAC)(3),, compared to vanadyl, gallium and indium curcumin, corroborating the importance of curcumin{\textquoteright}s free phenolic OH groups for scavenging oxidants, and correlated with reduced cytotoxic potential. (c) 2005 Elsevier Inc. All rights reserved.}, keywords = {ANALOGS, antioxidant capacity, ANTIOXIDANT MECHANISM, ANTITUMOR ACTIVITY, BINDING, COORDINATION CHEMISTRY, curcumin, cytotoxicity, DERIVATIVES, diacetylcurcumin, gallium, GROUP, indium, INSULIN MIMICS, MANGANESE COMPLEXES, RADICAL SCAVENGING ABILITY, TOXICITY, VANADIUM}, isbn = {0162-0134}, url = {://000233322800012}, author = {Mohammadi, K. and Thompson, K. H. and Patrick, B. O. and Storr, T. and Martins, C. and Polishchuk, E. and Yuen, V. G. and McNeill, J. H. and Orvig, Chris} } @article {1286, title = {Synthesis, characterization, and reactivity of the first hafnium alkyl complex stabilized by amidate ligands}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {83}, number = {6-7}, year = {2005}, note = {ISI Document Delivery No.: 963UVTimes Cited: 7Cited Reference Count: 20}, month = {Jun}, pages = {1037-1042}, type = {Article}, abstract = {A photo and thermally stable bis(amidate)-dibenzyl complex of Hf ([(DMP)(NO)(Ph)](2)Hf(CH2Ph)(2)(THF) (2a) was formed as a monosolvated THF adduct in near quantitative yield from Hf(CH2Ph)(4) and N-2,6-dimethylphenyl(phenyl)amide (1). Isomerization between the THF-bound product and the THF-free product can be observed visually by the conversion from a red-orange product at low temperatures to a pale yellow product at high temperatures. Solid-state crystallographic characterization of the orange product confirmed its constitution as a monosolvated species. Kinetic parameters for the exchange of the THF moiety were determined from variable-temperature NMR experiments. The product of the hydrolysis of the Hf dibenzyl species by water was characterized by X-ray crystallography, and was found to be a rare tetrametallic Hf oxo cluster species (3).}, keywords = {amidate, CHEMISTRY, COORDINATION CHEMISTRY, CRYSTAL, exchange processes, hafnium, HYDROAMINATION, MOLECULAR-STRUCTURE, organometallic, protonolysis, TITANIUM}, isbn = {0008-4042}, url = {://000231832500064}, author = {Thomson, R. K. and Patrick, B. O. and Schafer, L. L.} } @article {1209, title = {Vanadium complexes with mixed O,S anionic ligands derived from maltol: Synthesis, characterization, and biological studies}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 32Cited Reference Count: 45}, month = {Apr}, pages = {2678-2688}, type = {Article}, abstract = {Four mixed O,S binding bidentate ligand precursors derived from maltol (3-hydroxy-2-methyl-4-pyrone) have been chelated to vanadium to yield new bis(ligand)oxovanadium(IV) and tris(ligand)vanadium(III) complexes. The four ligand precursors include two pyranthiones, 3-hydroxy-2- m ethyl-4-pyranthione, commonly known as thiomaltol (Htma), and 2-ethyl-3-hydroxy-4-pyranthione, commonly known as ethylthiomaltol (Hetma), as well as two pyridinethiones, 3-hydroxy-2-methyl-4(H)-pyridinethione (Hmppt) and 3-hydroxy-1,2-dimethyi-4-pyridinethione (Hdppt). Vanadium complex formation was confirmed by elemental analysis, mass spectrometry, and IR and EPR (where possible) spectroscopies. The X-ray structure of oxobis(thiomaltolato)vanadium(IV),VO(tma)(2), was also determined; both cis and trans isomers were isolated in the same asymmetric unit. In both isomers, the two thiomaltolato ligands are arranged around the base of the square pyramid with the V=O linkage perpendicular; the vanadium atom is slightly displaced from the basal plane [V(1) = 0.656(3) angstrom, V(2) = 0.664(2) angstrom]. All of the new complexes were screened for insulin-enhancing effectiveness in streptozotocin-induced diabetes in rats, and VO(tma)2 was profiled metabolically for urinary vanadium and ligand clearance by GFAAS and ESIMS, respectively. The new vanadium complexes did not lower blood glucose levels acutely, possibly because of rapid dissociation and excretion.}, keywords = {BIOCHEMISTRY, BIS(MALTOLATO)OXOVANADIUM(IV), COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EPR, IN-VITRO, METAL, OXOVANADIUM(IV)}, isbn = {0020-1669}, url = {://000228374400018}, author = {Monga, V. and Thompson, K. H. and Yuen, V. G. and Sharma, V. and Patrick, B. O. and McNeill, J. H. and Orvig, Chris} } @article {1209, title = {Vanadium complexes with mixed O,S anionic ligands derived from maltol: Synthesis, characterization, and biological studies}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 32Cited Reference Count: 45}, month = {Apr}, pages = {2678-2688}, type = {Article}, abstract = {Four mixed O,S binding bidentate ligand precursors derived from maltol (3-hydroxy-2-methyl-4-pyrone) have been chelated to vanadium to yield new bis(ligand)oxovanadium(IV) and tris(ligand)vanadium(III) complexes. The four ligand precursors include two pyranthiones, 3-hydroxy-2- m ethyl-4-pyranthione, commonly known as thiomaltol (Htma), and 2-ethyl-3-hydroxy-4-pyranthione, commonly known as ethylthiomaltol (Hetma), as well as two pyridinethiones, 3-hydroxy-2-methyl-4(H)-pyridinethione (Hmppt) and 3-hydroxy-1,2-dimethyi-4-pyridinethione (Hdppt). Vanadium complex formation was confirmed by elemental analysis, mass spectrometry, and IR and EPR (where possible) spectroscopies. The X-ray structure of oxobis(thiomaltolato)vanadium(IV),VO(tma)(2), was also determined; both cis and trans isomers were isolated in the same asymmetric unit. In both isomers, the two thiomaltolato ligands are arranged around the base of the square pyramid with the V=O linkage perpendicular; the vanadium atom is slightly displaced from the basal plane [V(1) = 0.656(3) angstrom, V(2) = 0.664(2) angstrom]. All of the new complexes were screened for insulin-enhancing effectiveness in streptozotocin-induced diabetes in rats, and VO(tma)2 was profiled metabolically for urinary vanadium and ligand clearance by GFAAS and ESIMS, respectively. The new vanadium complexes did not lower blood glucose levels acutely, possibly because of rapid dissociation and excretion.}, keywords = {BIOCHEMISTRY, BIS(MALTOLATO)OXOVANADIUM(IV), COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EPR, IN-VITRO, METAL, OXOVANADIUM(IV)}, isbn = {0020-1669}, url = {://000228374400018}, author = {Monga, V. and Thompson, K. H. and Yuen, V. G. and Sharma, V. and Patrick, B. O. and McNeill, J. H. and Orvig, Chris} } @article {898, title = {Metal-metal bonded homo- and heterobimetallic compounds of Pt(I) and Pd(I) supported by a bridging-N,P : N {\textquoteright},P {\textquoteright} moiety of a potentially hexadentate ligand}, journal = {Inorganic Chemistry}, volume = {43}, number = {13}, year = {2004}, note = {ISI Document Delivery No.: 831AQTimes Cited: 11Cited Reference Count: 55}, month = {Jun}, pages = {4056-4063}, type = {Article}, abstract = {Reactions of metal-metal bonded homobimetallic (Pd-2) and heterobimetallic (PtPd) complexes, supported by a P,P{\textquoteright}-bridging-bis(P,N-chelating) coordination mode of the potentially hexadentate ligand 1,1-bis[di(o-N,N-dimethylanilinyl)phosphino]methane (dmapm), with CO, diethylacetylenedicarboxylate (DEAD), and thiols (FISH) in CH2Cl2 are described. At room temperature, rac-Pd2Cl2(mu-N,P:P{\textquoteright},N{\textquoteright}-dmapm) gives the stable complexes Pd2Cl2(mu-CO)(2)-(mu-P:P{\textquoteright}-dmapm) and PdCl(eta(2)-DEAD)(mu-P:P{\textquoteright}, N-dmapm)PdCl (which is fluxional in solution), while rac-PtPdCl2(mu-N,P:P{\textquoteright}, N{\textquoteright}-dmapm) disproportionates to PtCl2(P,P{\textquoteright}-dmapm) and Pd metal, although at low temperature intermediate carbonyl species are detected in the CO reaction. The reactions with thiols in the presence of triflic acid (HOTf) generate rac-[MPdCl2(mu-SR)(mu-N,P:P{\textquoteright},N{\textquoteright}-dmapm)][OTf] and H-2 for both M = Pt and Pd. In CH2Cl2, PdX2(dmapm) species (X = halide or CN) exist as equilibrium mixtures of P,P{\textquoteright} and P,N-ligated forms. For X = Cl, the P,P{\textquoteright}-PN equilibrium is governed by DeltaHdegrees = -5.5 +/- 0.5 kJ mol(-1) and DeltaSdegrees = 10 +/- 1 J mol(-1) K-1, and the ring-strain energy within the P,P{\textquoteright}-isomer is similar to32 kJ mol(-1); the equilibrium increasingly favors the P,N-form with X = CN much greater than I > Br > Cl. The solid-state structures of rac-[PtPdCl2(mu-SEt)(mu-NP:P{\textquoteright},N{\textquoteright}-dmapm)][OTf] and PdCl2(P,N-dmapm) are presented; the latter contains both bound and free N- and P-atoms of identical types in the same molecule and permits an assessment of sigma- and pi-bonding between these atoms and Pd.}, keywords = {A-FRAME COMPLEXES, BINUCLEAR COMPLEXES, COORDINATION CHEMISTRY, MOLECULAR-STRUCTURES, OXIDATIVE CARBONYLATION, PD DINUCLEAR COMPLEX, PLATINUM COMPLEXES, RING STRAIN ENERGIES, STRUCTURAL SYSTEMATICS, TERTIARY PHOSPHINE-LIGANDS}, isbn = {0020-1669}, url = {://000222165700043}, author = {Jones, N. D. and Foo, S. J. L. and Patrick, B. O. and James, Brian R.} } @article {615, title = {Activation and functionalization of molecular nitrogen by metal complexes}, journal = {Chemical Record}, volume = {3}, number = {1}, year = {2003}, note = {ISI Document Delivery No.: 669WPTimes Cited: 48Cited Reference Count: 52}, pages = {2-11}, type = {Article}, abstract = {Molecular nitrogen is intrinsically unreactive, so much so that it has confounded chemists for decades in attempts to functionalize this abundant diatomic molecule. While biological systems and industrial processes can fix nitrogen to form ammonia, the challenge is to discover a process that involves a homogeneous catalyst that can utilize N-2 as a feedstock to generate higher value organonitrogen materials. In this review, the activation of molecular nitrogen by transition metal complexes is reviewed with the view to present new kinds of transformations for coordinated dinitrogen. Moreover, some reaction types that are as yet unknown are outlined to try and stimulate further research in this area. (C) 2003 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.}, keywords = {BRIDGING N-2 UNIT, CHEMISTRY, COORDINATED, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, DINITROGEN, DINITROGEN COMPLEXES, END-ON, FIXATION, nitrogen fixation, nitrogenase, REDUCTION, SIDE-ON, transition metal complexes, ZIRCONIUM}, isbn = {1527-8999}, url = {://000182373700001}, author = {Fryzuk,Michael D.} } @article {616, title = {Reduction of hafnium(IV) complexes in the presence of molecular nitrogen: Attempts to form dinitrogen complexes of the heaviest group 4 element}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {81}, number = {11}, year = {2003}, note = {ISI Document Delivery No.: 746YXTimes Cited: 10Cited Reference Count: 28}, month = {Nov}, pages = {1376-1387}, type = {Article}, abstract = {The reaction of [P2N2]Li-2(dioxane)(2) with HfCl4(THF)(2) (where [P2N2] = PhP(CH2SiMe2NSiMe2CH2)(2)PPh) results in the formation of the hafnium dichloride complex [P2N2]HfCl2 (1). The behaviour of 1 as a potential precursor in the generation of a dinitrogen coordination complex is described. Reduction of 1 with potassium-graphite (C8K), under dinitrogen, under a variety of conditions led to a number of products, one of which is the dinuclear derivative with bridging P-phenyl groups that has the general formula {[P2N2]Hf}(2) (2). Reduction of the hafnium diiodide [P2N2]HfI2 (3) - prepared via the reaction of 1 with excess Me3SiI - with C8K results in the formation of ([P2N2]Hf)(2)(mu-eta(2):eta(2)-N-2) (4) as the major product of the reaction, while {[P2N2]Hf}(2) (2) and [P2N2]Hf(C7H8) (5) appear to be minor products. Reaction of 1 with 2 equiv of MeMgCl gives [P2N2]HfMe2 (6), which, upon exposure to an atmosphere of H-2, gives the hafnium tetrahydride {[P2N2]Hf}(2)(m-H)(4) (7).}, keywords = {COORDINATION CHEMISTRY, DERIVATIVES, DINITROGEN, donor ligands, FLUXIONAL BEHAVIOR, hafnium, hydride, macrocycle, mixed, {ALKYL}, isbn = {0008-4042}, url = {://000186777600031}, author = {Fryzuk,Michael D. and Corkin, J. R. and Patrick, B. O.} } @article {734, title = {Vanadium and niobium diamidophosphine complexes and their reactivity}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {81}, number = {12}, year = {2003}, note = {ISI Document Delivery No.: 751CNTimes Cited: 7Cited Reference Count: 27}, month = {Dec}, pages = {1431-1437}, type = {Article}, abstract = {The tridentate ligand precursors R{\textquoteright}P(CH2SiMe2NR")(2) ((R{\textquoteright}R{\textquoteright}{\textquoteright})[NPN]: R{\textquoteright} = Cy, Ph; R" = Ph, Mes, Me) were prepared from metathesis reactions of a lithiated amine, chloro(chloromethyl)dimethylsilane, the appropriate 1degrees phosphine, and n-butyl lithium and were isolated as solvent adducts. Metathesis between (CyPh)[NPN]Li-2(OEt2), 2, and VCl3(THF)(3) afforded ((CyPh)[NPN]VCl)(2), 7, whose solid-state structure was established by X-ray crystallography. Reduction attempts of the ((R{\textquoteright}R{\textquoteright}{\textquoteright})[NPN]VCl)(2) species with KC8 incorporated molecular nitrogen but were complicated by imide formation and ligand decomposition. Metathesis of 2 with NbCl2Me3 afforded the highly unstable complex (CyPh)[NPN]NbMe3, 15. Attempts to hydrogenate this species were unsuccessful.}, keywords = {3-COORDINATE MOLYBDENUM(III), BRIDGING N-2 UNIT, COORDINATION, COORDINATION CHEMISTRY, DINITROGEN COMPLEX, END-ON, FUNCTIONALIZATION, HYDROGENATION, LIGAND, METATHESIS, NIOBIUM, REDUCTION, REDUCTIVE CLEAVAGE, SIDE-ON, TANTALUM COMPLEX, VANADIUM}, isbn = {0008-4042}, url = {://000187035400001}, author = {Shaver, M. P. and Thomson, R. K. and Patrick, B. O. and Fryzuk,Michael D.} } @article {358, title = {Formation of ruthenium(II)-bis(phosphine) monoxide complexes from the bis(phosphine) precursors: BINAP-monoxide (BINAPO) as a six-electron (P,O,eta(2)-naphthyl) donor}, journal = {Organometallics}, volume = {21}, number = {22}, year = {2002}, note = {ISI Document Delivery No.: 607EFTimes Cited: 31Cited Reference Count: 105}, month = {Oct}, pages = {4672-4679}, type = {Review}, abstract = {{Aerobic oxidation of one P atom in cis-RuCl2(P-P)(L-2) complexes (P-P = (R)-BINAP (2,2{\textquoteright}-bis(diphenylphosphino)-1,1{\textquoteright}-binaphthyl) or dppb (1,4-bis(diphenylphosphino)butane)}, keywords = {ASYMMETRIC HYDROGENATION, CATALYTIC ENANTIOSELECTIVE, CHIRAL RUTHENIUM(II) CATALYSTS, COORDINATION CHEMISTRY, DIELS-ALDER REACTIONS, HYDROGENATION, MEO-BIPHEP, P-C BOND, PHOSPHINE OXIDE LIGANDS, STEREOSELECTIVE, X-RAY}, isbn = {0276-7333}, url = {://000178778100015}, author = {Cyr, P. W. and Rettig, S. J. and Patrick, B. O. and James, Brian R.} } @article {495, title = {Magnetic and structural studies on 1,3-diazolate complexes of cobalt(II) - The characterization of three new cobalt(II) molecule-based magnets}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {80}, number = {2}, year = {2002}, note = {ISI Document Delivery No.: 531ZZTimes Cited: 10Cited Reference Count: 35}, month = {Feb}, pages = {133-140}, type = {Article}, abstract = {{The cobalt(II) compounds ([Co(imid)(2)](x) (1), [Co(2-meimid)(2)](x) (2), [Co(4-meimid)(2)](x) (3), [Co(benzimid)(2)](x) (4), and [Co-3(imid)(6)(imidH)(2)](x) (5) (imid = imidazolate}, keywords = {1, 3, 3-diazolates, 5-DIMETHYLPYRAZOLATE, BR, canted spins, CH3, cobalt(II), COMPLEXES, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, LIGANDS, LOW-TEMPERATURES, METAL PYRAZOLATE POLYMERS, METALLOCENES, molecule-based magnets, SYSTEMS}, isbn = {0008-4042}, url = {://000174448300002}, author = {Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {495, title = {Magnetic and structural studies on 1,3-diazolate complexes of cobalt(II) - The characterization of three new cobalt(II) molecule-based magnets}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {80}, number = {2}, year = {2002}, note = {ISI Document Delivery No.: 531ZZTimes Cited: 10Cited Reference Count: 35}, month = {Feb}, pages = {133-140}, type = {Article}, abstract = {{The cobalt(II) compounds ([Co(imid)(2)](x) (1), [Co(2-meimid)(2)](x) (2), [Co(4-meimid)(2)](x) (3), [Co(benzimid)(2)](x) (4), and [Co-3(imid)(6)(imidH)(2)](x) (5) (imid = imidazolate}, keywords = {1, 3, 3-diazolates, 5-DIMETHYLPYRAZOLATE, BR, canted spins, CH3, cobalt(II), COMPLEXES, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, LIGANDS, LOW-TEMPERATURES, METAL PYRAZOLATE POLYMERS, METALLOCENES, molecule-based magnets, SYSTEMS}, isbn = {0008-4042}, url = {://000174448300002}, author = {Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {5148, title = {Insulin-enhancing vanadium(III) complexes}, journal = {Inorganic Chemistry}, volume = {40}, number = {18}, year = {2001}, note = {ISI Document Delivery No.: 466JNTimes Cited: 67Cited Reference Count: 54}, month = {Aug}, pages = {4686-4690}, type = {Article}, abstract = {Simple, high-yield, large-scale syntheses of the V(III) complexes tris(maltolato)vanadium(III), V(ma)(3), tris-(ethyhmaltolato)vanadium(HI), V(ema)(3), tris(kojato)vanadium(III) monchydrate, V(koj)(3).H2O, and tris(1,2-dimethyl-3-hydroxy-4-pyridinonato)vanadium(III) dodecahydrate, V(dpp)(3). 12H(2)O, are described; the characterization of these complexes by various methods and, in the case of V(dpp)(3). 12H(2)O, by an X-ray crystal structure determination, is reported. The ability of these complexes to normalize glucose levels in the STZ-diabetic rat model has been examined and compared with that of the benchmark compound BMOV (bis(maltolato)oxovanadium(IV)), an established insulin-enhancing agent.}, keywords = {AGENT, aluminum, BIS(MALTOLATO)OXOVANADIUM(IV), CHELATE COMPLEXES, COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, DIABETIC RATS, gallium, GLUCOSE, LIGANDS, MIMETIC}, isbn = {0020-1669}, url = {://000170642600028}, author = {Melchior, M. and Rettig, S. J. and Liboiron, B. D. and Thompson, K. H. and Yuen, V. G. and McNeill, J. H. and Orvig, Chris} } @article {5160, title = {Polybis(pyrazolato)iron(II) and poly-2,2 {\textquoteright} bipyridinetetrakis(imidazolato)-diiron(II) and -dicobalt(II): from short-range magnetic interactions in the pyrazolate to long-range ferromagnetic ordering in the imidazolates}, journal = {Polyhedron}, volume = {20}, number = {11-14}, year = {2001}, note = {ISI Document Delivery No.: 451LWTimes Cited: 11Cited Reference Count: 307th International Conference on Molecule-Base Magnets (ICMM 2000)SEP 16-21, 2000SAN ANTONIO, TEXAS}, month = {May}, pages = {1577-1585}, type = {Proceedings Paper}, abstract = {Polybis(pyrazolato)iron(II), [Fe(pz)(2)](x) (1) has an extended chain ID structure in which iron ions are doubly bridged by pyrazolate ligands. The compound exhibits weak antiferromagnetic interactions. The magnetic susceptibility data were fit to a Heisenberg model for chains of antiferromagnetically coupled S= 2 metal centers, yielding the magnetic parameters -J= 0.59 cm(-1) and g = 2.01. Poly-2,2{\textquoteright}-bipyridinetetrakis(imidazolato)diiron(II), [Fe-2(imid)(3)(bipy)](x) (2) and the isomorphous cobalt compound, 3, have 2D extended structures in which double layered sheets of alternating tetrahedrally and octahedrally coordinated metal ions are linked by single bridging imidazolates. The octahedral metal centers are additionally coordinated by 2,2{\textquoteright}-bipyridine ligands, which occupy positions between the sheets, isolating the sheets from each other. The presence of the two different iron centers in 2 is confirmed by ambient temperature Mossbauer studies. The magnetic properties of these materials reveal a transition to long-range ferromagnetic order below 11 K for 2 and below 13 K for 3. Both materials reveal magnetic hysteresis at 4.8 K. Analysis of the data yield, for 2 and 3, respectively, coercive fields of 15 and 125 G and remanent magnetizations of 200 and 1900 cm(3) G mol(-1). (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {antiferromagenetism, COMPLEXES, COORDINATION CHEMISTRY, crystal structures, ferromagnetic ordering, iron(II) and cobalt(II) imidazolates, iron(II) pyrazolate, LIGANDS, LOW-TEMPERATURES, METALLOCENES, MOSSBAUER, POLYMERS, SERIES, SYSTEMS}, isbn = {0277-5387}, url = {://000169804400076}, author = {Patrick, B. O. and Reiff, W. M. and Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {5160, title = {Polybis(pyrazolato)iron(II) and poly-2,2 {\textquoteright} bipyridinetetrakis(imidazolato)-diiron(II) and -dicobalt(II): from short-range magnetic interactions in the pyrazolate to long-range ferromagnetic ordering in the imidazolates}, journal = {Polyhedron}, volume = {20}, number = {11-14}, year = {2001}, note = {ISI Document Delivery No.: 451LWTimes Cited: 11Cited Reference Count: 307th International Conference on Molecule-Base Magnets (ICMM 2000)SEP 16-21, 2000SAN ANTONIO, TEXAS}, month = {May}, pages = {1577-1585}, type = {Proceedings Paper}, abstract = {Polybis(pyrazolato)iron(II), [Fe(pz)(2)](x) (1) has an extended chain ID structure in which iron ions are doubly bridged by pyrazolate ligands. The compound exhibits weak antiferromagnetic interactions. The magnetic susceptibility data were fit to a Heisenberg model for chains of antiferromagnetically coupled S= 2 metal centers, yielding the magnetic parameters -J= 0.59 cm(-1) and g = 2.01. Poly-2,2{\textquoteright}-bipyridinetetrakis(imidazolato)diiron(II), [Fe-2(imid)(3)(bipy)](x) (2) and the isomorphous cobalt compound, 3, have 2D extended structures in which double layered sheets of alternating tetrahedrally and octahedrally coordinated metal ions are linked by single bridging imidazolates. The octahedral metal centers are additionally coordinated by 2,2{\textquoteright}-bipyridine ligands, which occupy positions between the sheets, isolating the sheets from each other. The presence of the two different iron centers in 2 is confirmed by ambient temperature Mossbauer studies. The magnetic properties of these materials reveal a transition to long-range ferromagnetic order below 11 K for 2 and below 13 K for 3. Both materials reveal magnetic hysteresis at 4.8 K. Analysis of the data yield, for 2 and 3, respectively, coercive fields of 15 and 125 G and remanent magnetizations of 200 and 1900 cm(3) G mol(-1). (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {antiferromagenetism, COMPLEXES, COORDINATION CHEMISTRY, crystal structures, ferromagnetic ordering, iron(II) and cobalt(II) imidazolates, iron(II) pyrazolate, LIGANDS, LOW-TEMPERATURES, METALLOCENES, MOSSBAUER, POLYMERS, SERIES, SYSTEMS}, isbn = {0277-5387}, url = {://000169804400076}, author = {Patrick, B. O. and Reiff, W. M. and Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {4694, title = {An iron-based molecular redox switch as a model for iron release from enterobactin via the salicylate binding mode}, journal = {Inorganic Chemistry}, volume = {38}, number = {22}, year = {1999}, note = {ISI Document Delivery No.: 255LLTimes Cited: 18Cited Reference Count: 51}, month = {Nov}, pages = {5007-5017}, type = {Article}, abstract = {The iron release mechanism from protonated ferric enterobactin [Fe-III(enterobactinH(3))] via the salicylate binding mode was probed. For this purpose, a tripodal dodecadentate Ligand incorporating three salicylamide (OO) and three bipyridine (NN) binding sites was synthesized as well as iron complexes thereof. It was shown that a ferric ion coordinates selectively to the hard salicylamides and a ferrous ion binds to the softer bipyridines. Upon reduction or oxidation, the iron translocates reversibly and intramolecularly from one site to the other, thus displaying switchlike properties. Both states were characterized by cyclic voltammetry and visible and Mossbauer spectroscopy. The Mossbauer spectrum for the ferric complex is fully consistent with that obtained by Pecoraro et al. upon lowering the pH of [Fe-III(enterobactin)](3-) solutions (Pecoraro, V. L., et al. J. Am. Chern. Sec. 1983, 105, 4617), thus supporting the alternative iron release mechanism from enterobactin via the salicylate binding mode.}, keywords = {COORDINATION CHEMISTRY, ESCHERICHIA-COLI, FERRIC ENTEROBACTIN, IRON(III) COORDINATION, LIGAND, METAL-COMPLEXES, SEQUESTERING AGENTS, SYNTHETIC ANALOGS, TRANSLOCATION, TRANSPORT COMPOUNDS}, isbn = {0020-1669}, url = {://000083670200015}, author = {Ward, T. R. and Lutz, A. and Parel, S. P. and Ensling, J. and Gutlich, P. and Buglyo, P. and Orvig, Chris} } @article {4705, title = {Kinetic and mechanistic aspects of sulfur recovery from Pd2I2(mu-S)(mu-dpm)(2) using I-2 and structures of Pd(II) complexes with the chelated monosulfide of dpm}, journal = {Inorganic Chemistry}, volume = {38}, number = {9}, year = {1999}, note = {ISI Document Delivery No.: 194LGTimes Cited: 21Cited Reference Count: 46}, month = {May}, pages = {2143-2149}, type = {Article}, abstract = {The Pd2X2(mu-S)(dpm)(2) complexes (2) (X = I, Br) react with halogens to yield PdX2(dpm) (3) and elemental sulfur. Kinetic and mechanistic studies on the X = I system in CHCl3 reveal that the reaction proceeds via addition of I-2 to give Pd2I4(dpm)(2) (4c), which then undergoes unimolecular decomposition to generate PdI2(dpm) (3c); the liberated sulfur concatenates to form elemental Ss The addition reaction is in the stopped-flow time regime and is first-order in both 2c and I-2, with Delta H-double dagger = 32 +/- 1 kJ mol-l and Delta S-double dagger = -91 +/- 3 J K-1 mol(-1). The slower decomposition reaction of 4c is first order in 4c, with Delta H-double dagger. = 80 +/- kJ mol(-1) and Delta S-double dagger = -26 +/- 3 J K-1 mol(-1). Byproduct PdX2(dpm(S)) (5) [dpm(S) = Ph2PCH2P(S)Ph-2] also forms under some conditions via reaction of 3 with an S, species (n < 8). Complexes 5 (X = Cl (a), Br (b), I(c)) were also synthesized directly, and the structure of the 5c species, as well as of [Pd(dpm(S))(2)]Cl-2, were determined by X-ray analyses that reveal the envelope configuration of the five-membered Pd-PPh2CH2P(S)Ph-2 chelate ring.}, keywords = {bis(diphenylphosphino)methane, CONVERSION, COORDINATION CHEMISTRY, HYDROGEN-SULFIDE, LIGANDS, MAGNETIC-RESONANCE, MOLECULAR-STRUCTURES, palladium, RAY CRYSTAL-STRUCTURE, SE}, isbn = {0020-1669}, url = {://000080194500029}, author = {Wong, T. Y. H. and Rettig, S. J. and James, Brian R.} } @article {4263, title = {One-electron transformations of paramagnetic cobalt complexes. Synthesis and structure of cobalt(II) amidodiphosphine halide and alkyl complexes and their reaction with alkyl halides}, journal = {Journal of the American Chemical Society}, volume = {120}, number = {39}, year = {1998}, note = {ISI Document Delivery No.: 127ZPTimes Cited: 33Cited Reference Count: 106}, month = {Oct}, pages = {10126-10135}, type = {Review}, abstract = {Complexes of the type CoX[N(SiMe2CH2PPh2)(2)], where X = Cl, Br, or I, can be prepared via reaction of CoX2 with LiN(SiMe2CH2PPh2)(2); these derivatives are tetrahedral high-spin d(7) systems. Reaction of these halide complexes with organolithium, sodium, or potassium reagents generates square-planar, low-spin hydrocarbyl complexes of the formula CoR[N(SiMe2CH2PPh2)(2)] (R = Me, CH2Ph, CH2SiMe3, C5H5). One-electron oxidations have been carried out; only the product of halide abstraction is observed. For example, addition of PhCH2X to the halide derivatives CoX[N(SiMe2CH2PPh2)(2)] generates trivalent, paramagnetic complexes, CoX2[N(SiMe2CH2PPh2)(2)]; these derivatives show variable-temperature magnetic susceptibility data that are consistent with zero-field splitting of the S = 1 state. Addition of methyl bromide or methyl iodide to low-spin CoMe[N(SiMe2CH2PPh2)(2)] results in the formation of the Co(II) halide derivatives CoX[N(SiMe2CH2PPh2)(2)] along with methane and bibenzyl. It is proposed that the Co(III) methyl halide complex CoMe(X) [N(SiMe2CH2PPh2)(2)] is unstable and loses methyl radical homolytically to generate the Co(II) halide derivative; the methyl subsequently reacts with the toluene solvent to produce methane and bibenzyl. Addition of excess benzyl halides has also been found to generate the Co(II) halide complexes initially, followed by a one-electron oxidation to the Co(II) dihalide derivatives. In much of the one-electron chemistry of the Co(II) derivatives incorporating the amidodiphosphine ligand, the decomposition of the putative but unstable Cs(III) alkyl halide derivative CoRX[N(SiMe2CH2PPh2)(2)] is proposed as a recurring event.}, keywords = {17-ELECTRON, BOND-DISSOCIATION ENERGIES, COORDINATION CHEMISTRY, D6 ML5 COMPLEXES, DERIVATIVES, HIGHER OXIDATION-STATES, KINETICS, LIGAND, ORGANIC HALIDES, RADICAL REACTIONS}, isbn = {0002-7863}, url = {://000076381000017}, author = {Fryzuk,Michael D. and Leznoff, D. B. and Thompson, R. C. and Rettig, S. J.} } @article {4290, title = {Tripodal trisamides based on nicotinic and picolinic acid derivatives}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {76}, number = {4}, year = {1998}, note = {ISI Document Delivery No.: 101TQTimes Cited: 6Cited Reference Count: 46}, month = {Apr}, pages = {414-425}, type = {Article}, abstract = {{A number of polydentate arylamide ligands have been prepared by coupling various acyclic tripodal or linear polyamines with derivatives of nicotinic and picolinic acids. Two synthetic procedures were utilized; tris {[(2-hydroxynicotinyl)carbonyl]-2-aminoethyl} (H3NICTREN) was prepared by Method A, the HOSu/DCC method, and the other arylamides in this study were prepared by Method B, the CDI method. Method A involved the reaction of N-hydroxysuccinimide with 2-hydroxynicotinic acid (in the presence of dicyclohexylcarbodiimide (DCC) as a dehydrative coupling reagent) to form the succinimide ester, followed by reaction with TREN to yield H3NICTREN. Method B involved reaction of a carboxylic acid (2-hydroxynicotinic, 3-hydroxypicolinic, nicotinic, or picolinic acids) with carbonyldiimidazole (CDI) to form the N-acylimidazolide, followed by reaction with the amine (TREN, TAME, spermidine, or TRPN) to yield the desired arylamide. The X-ray structure of 1,1,1-tris{[(3 -hydroxypicolinyl) carbonyl] -2-aminomethyl} ethane (H3PICTBME) was determined; crystals of H(3)PICTAME are monoclinic}, keywords = {aluminum, arylamide, CHELATE COMPLEXES, COORDINATION CHEMISTRY, DISTANCES, ENTEROBACTIN ANALOGS, FERRIC ENTEROBACTIN, gallium, hydrogen bonding, MICROBIAL IRON TRANSPORT, NEUTRAL WATER, preorganization, STABILITY}, isbn = {0008-4042}, url = {://000074884600007}, author = {Hoveyda, H. R. and Karunaratne, V. and Nichols, C. J. and Rettig, S. J. and Stephens, A. K. W. and Orvig, Chris} } @article {3815, title = {Bis(ligand) rhenium(V) and technetium(V) complexes of two naturally occurring binding moieties (oxazoline and thiazoline)}, journal = {Inorganic Chemistry}, volume = {35}, number = {2}, year = {1996}, note = {ISI Document Delivery No.: TR240Times Cited: 39Cited Reference Count: 19}, month = {Jan}, pages = {368-372}, type = {Article}, abstract = {{Attempts to prepare tris(ligand) metal complexes of technetium in intermediate oxidation states with potentially bidentate oxazoline- and thiazoline-containing ligands were unsuccessful; when pertechnetate was reduced in the presence of excess ligand, TcO2 . xH(2)O was produced. Instead, by reaction with preformed M . O cores, a series of oxotechnetium(V) and oxorhenium(V) complexes of the formula MOXL(2) (M = Re}, keywords = {COORDINATION CHEMISTRY, RADIOPHARMACEUTICALS, RAY CRYSTAL-STRUCTURE, SIDEROPHORE, TC-99M}, isbn = {0020-1669}, url = {://A1996TR24000018}, author = {Shuter, E. and Hoveyda, H. R. and Karunaratne, V. and Rettig, S. J. and Orvig, Chris} } @article {2864, title = {HEXADENTATE N3O3 AMINE PHENOL LIGANDS FOR GROUP-13 METAL-IONS - EVIDENCE FOR INTRASTRAND AND INTERSTRAND HYDROGEN-BONDS IN POLYDENTATE TRIPODAL AMINE PHENOLS}, journal = {Inorganic Chemistry}, volume = {32}, number = {20}, year = {1993}, note = {ISI Document Delivery No.: LZ815Times Cited: 37Cited Reference Count: 27}, month = {Sep}, pages = {4268-4276}, type = {Article}, abstract = {{Several N3O3 amine phenols (H-3L1 = 1,2,3-tris((2-hydrox benzyl)amino)propane; H-3L2 = 1,2,3-tris((5-chloro-2-hydroxybenzyl)amino)propane; H-3L3 = 1,2,3-tris((2-hydroxy-5-methoxybenzyl)amino)propane; H-3L4 = 1,2,3-tris((3,5-dichloro-2-hydroxybenzyl)amino)propane) were prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). The N3O3 amine phenols are KBH4 reduction products of the corresponding Schiff bases derived from the condensation reactions of tap (tap = 1,2,3-triaminopropane) with 3 equiv of either salicylaldehyde or ring-substituted salicylaldehydes. Neutral binary metal complexes, [M(L)] (M = Al}, keywords = {COMPLEXES, COORDINATION CHEMISTRY, MOLECULES, supramolecular chemistry}, isbn = {0020-1669}, url = {://A1993LZ81500019}, author = {Liu, S. and Wong, E. and Rettig, S. J. and Orvig, Chris} } @article {6969, title = {HEPTADENTATE LIGANDS FOR THE LANTHANIDES - THE 1ST STRUCTURALLY CHARACTERIZED EXAMPLE OF A LANTHANIDE HEPTADENTATE LIGAND COMPLEX - (TRIS(3-AZA-4-METHYL-6-OXOHEPT-4-EN-1-YL)AMINE)YTTERBIUM(III)}, journal = {Journal of the American Chemical Society}, volume = {113}, number = {7}, year = {1991}, note = {ISI Document Delivery No.: FD837Times Cited: 55Cited Reference Count: 29}, month = {Mar}, pages = {2528-2532}, type = {Article}, abstract = {{Several binary heptacoordinate-N4O3-ligand LnL complexes of the lanthanides have been prepared and characterized. The heptadentate ligands are the Schiff base condensation products of tris(2-aminoethyl)amine with 3 equiv of either acetylacetone (to form H-3trac) or a hydroxyacetophenone (to form H-3hatren or H-3datren). The complexes hydrolyze easily but most of the Ln(trac) complexes are stable enough to sublime. Crystals of Yb(trac) were isolated by sublimation, and its structure has been solved; it is the first structurally characterized example of a lanthanide heptadentate ligand complex. Crystals of Yb(trac) are monoclinic}, keywords = {AGENTS, COORDINATION CHEMISTRY, CRYSTAL, MOLECULAR-STRUCTURE}, isbn = {0002-7863}, url = {://A1991FD83700029}, author = {Berg, D. J. and Rettig, S. J. and Orvig, Chris} }