@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 {2690, title = {A triple-stranded helicate and mesocate from the same metal and ligand}, journal = {Chemical Communications}, number = {45}, year = {2009}, note = {ISI Document Delivery No.: 517VNTimes Cited: 4Cited Reference Count: 37Zhang, Zhan Dolphin, David}, pages = {6931-6933}, type = {Article}, abstract = {A pair of triple-stranded helicates and mesocates were, for the first time, isolated from the same reaction of a novel alpha-free bis(dipyrromethene)ligand with either Co3+ or Fe3+.}, keywords = {CHEMISTRY, cobalt(II), COMPLEXES, dipyrrins, DIPYRROMETHENE LIGANDS, INVERSION, iron, MECHANISM, STRUCTURAL-CHARACTERIZATION, TWIST}, isbn = {1359-7345}, url = {://000271647200007}, author = {Zhang, Z. and Dolphin, D.} } @article {2024, title = {99m-Technetium carbohydrate conjugates as potential agents in molecular imaging}, journal = {Chemical Communications}, number = {41}, year = {2008}, note = {ISI Document Delivery No.: 365LHTimes Cited: 19Cited Reference Count: 97Bowen, Meryn L. Orvig, Chris}, pages = {5077-5091}, type = {Article}, abstract = {This feature article covers recent reports of work towards the development of Tc-99m-carbohydrate based agents for use in SPECT imaging, particularly of cancerous tissue. An outline of some of the key biological functions and coordination chemistry of carbohydrates is given, along with an introduction to bioconjugation and molecular imaging. Technetium coordination chemistry and the subset of this involving bioconjugates are discussed before moving into the focus of the article: glycoconjugates of Tc-99m(v) and the more recently developed [Tc-99m(I)(CO)(3)](+). Significant work in the last decade has featured the very attractive [Tc-99m(CO)(3)](+) core, and the ligand sets designed for this core are discussed in detail.}, keywords = {ANTITUMOR-ACTIVITY, BIFUNCTIONAL CHELATORS, BIOLOGICAL EVALUATION, D-GLUCOSE, IN-VITRO, ISOSTRUCTURAL RE, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TC-99M COMPLEXES, TRICARBONYL COMPLEXES}, isbn = {1359-7345}, url = {://000260407400002}, author = {Bowen, M. L. and Orvig, Chris} } @article {1390, title = {Carbohydrate-appended 3-hydroxy-4-pyridinone complexes of the [M(CO)(3)](+) core (M) Re, Tc-99m, Re-186)}, journal = {Bioconjugate Chemistry}, volume = {17}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 085LXTimes Cited: 21Cited Reference Count: 69Ferreira, Cara L. Bayly, Simon R. Green, David E. Storr, Tim Barta, Cheri A. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Sep}, pages = {1321-1329}, type = {Article}, abstract = {This work describes the use of 3-hydroxy-4-pyridinone ligands for binding the [M(CO)(3)](+) core ( M) Re, Tc) in the context of preparing novel Tc( I) and Re( I) glucose conjugates. Five pyridinone ligands bearing pendent carbohydrate moieties, HL1-5, were coordinated to the [M(CO)(3)](+0) core on the macroscopic scale ( M) Re) and on the tracer scale (M) = Tc-99m, Re-186). On the macroscopic scale the complexes, ReL1-5(CO)(3)(H{\O}-2), were thoroughly characterized by mass spectrometry, IR spectroscopy, UV-visible spectroscopy, elemental analysis, and 1D/2D NMR spectroscopy. Characterization confirmed the bidentate coordination of the pyridinone and the pendent nature of the carbohydrate and suggests the presence of a water molecule in the sixth coordination site. In preliminary biological evaluation, both the ligands and complexes were assessed as potential substrates or inhibitors of hexokinase, but showed no activity. Labeling via the [Tc-99m(CO)(3)(H2O)(3)](+) precursor gave the tracer species (TcL1-5)-Tc-99m(CO)(3)(H2O) in high radiochemical yields. Similar high radiochemical yields when labeling with Re-186 were facilitated by in situ preparation of the [Re-186( CO)(3)(H2O)(3)](+) species in the presence of HL1-5 to give (ReL1-5)-Re-186(CO)(3)(H2O). Stability challenges, incubating (TcL1-5)-Tc-99m(CO)(3)(H2O) in the presence of excess cysteine and histidine, confirmed complex stability up to 24 h.}, keywords = {5-HT1A RECEPTOR, BIFUNCTIONAL LIGAND, BIOMOLECULES, GLUCOSE, IMAGING AGENTS, IN-VITRO, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRICARBONYL COMPLEXES, TRIDENTATE LIGANDS}, isbn = {1043-1802}, url = {://000240606700027}, author = {Ferreira, C. L. and Bayly, S. R. and Green, D. E. and Storr, T. and Barta, C. A. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @article {1390, title = {Carbohydrate-appended 3-hydroxy-4-pyridinone complexes of the [M(CO)(3)](+) core (M) Re, Tc-99m, Re-186)}, journal = {Bioconjugate Chemistry}, volume = {17}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 085LXTimes Cited: 21Cited Reference Count: 69Ferreira, Cara L. Bayly, Simon R. Green, David E. Storr, Tim Barta, Cheri A. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Sep}, pages = {1321-1329}, type = {Article}, abstract = {This work describes the use of 3-hydroxy-4-pyridinone ligands for binding the [M(CO)(3)](+) core ( M) Re, Tc) in the context of preparing novel Tc( I) and Re( I) glucose conjugates. Five pyridinone ligands bearing pendent carbohydrate moieties, HL1-5, were coordinated to the [M(CO)(3)](+0) core on the macroscopic scale ( M) Re) and on the tracer scale (M) = Tc-99m, Re-186). On the macroscopic scale the complexes, ReL1-5(CO)(3)(H{\O}-2), were thoroughly characterized by mass spectrometry, IR spectroscopy, UV-visible spectroscopy, elemental analysis, and 1D/2D NMR spectroscopy. Characterization confirmed the bidentate coordination of the pyridinone and the pendent nature of the carbohydrate and suggests the presence of a water molecule in the sixth coordination site. In preliminary biological evaluation, both the ligands and complexes were assessed as potential substrates or inhibitors of hexokinase, but showed no activity. Labeling via the [Tc-99m(CO)(3)(H2O)(3)](+) precursor gave the tracer species (TcL1-5)-Tc-99m(CO)(3)(H2O) in high radiochemical yields. Similar high radiochemical yields when labeling with Re-186 were facilitated by in situ preparation of the [Re-186( CO)(3)(H2O)(3)](+) species in the presence of HL1-5 to give (ReL1-5)-Re-186(CO)(3)(H2O). Stability challenges, incubating (TcL1-5)-Tc-99m(CO)(3)(H2O) in the presence of excess cysteine and histidine, confirmed complex stability up to 24 h.}, keywords = {5-HT1A RECEPTOR, BIFUNCTIONAL LIGAND, BIOMOLECULES, GLUCOSE, IMAGING AGENTS, IN-VITRO, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRICARBONYL COMPLEXES, TRIDENTATE LIGANDS}, isbn = {1043-1802}, url = {://000240606700027}, author = {Ferreira, C. L. and Bayly, S. R. and Green, D. E. and Storr, T. and Barta, C. A. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @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 {1267, title = {Carbohydrate-appended 2,2 {\textquoteright}-dipicolylamine metal complexes as potential imaging agents}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 44Cited Reference Count: 58}, month = {Apr}, pages = {2698-2705}, type = {Article}, abstract = {Three discrete carbohydrate-appended 2,2{\textquoteright}-dipicolylamine ligands were complexed to the {M(CO)3}(+) (M = Tc-99m/ Re) core: 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-D-glucopyranoside (L-1), 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-Dxylopyranoside (L-2), and 2-(bis(2-pyridinylmethyl)amino)ethyl-alpha-D-mannopyranoside (L-3). An ethylene spacer is used to separate the carbohydrate moiety and the dipicolylamine (DPA) function in all three ligands. The Re complexes [Re(L1-3)(CO)(3)]Br were characterized by H-1 and C-13 1D/2D NMR spectroscopies, which confirmed the pendant nature of the carbohydrate moieties in solution. NMR measurements also established the long-range asymmetric effect of the carbohydrate functions on the chelating portion of the ligand. One analogue, [Re(L-1)(CO)(3)]Cl, was characterized in the solid state by X-ray crystallography. Further characterization was provided by IR spectroscopy, elemental analysis, conductivity, and mass spectrometry. Radiolabeling of L-1-L-3 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded high yield compounds of identical character to the Re analogues. The radiolabeled compounds were found to be stable toward ligand exchange in the presence of a large excess of either cysteine or histidine over a 24-h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, BOMBESIN ANALOG, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, LIGANDS, PALLADIUM(II) COMPLEXES, RHENIUM CARBONYL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRIDENTATE}, isbn = {0020-1669}, url = {://000228374400020}, author = {Storr, T. and Sugai, Y. and Barta, C. A. and Mikata, Y. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1267, title = {Carbohydrate-appended 2,2 {\textquoteright}-dipicolylamine metal complexes as potential imaging agents}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 44Cited Reference Count: 58}, month = {Apr}, pages = {2698-2705}, type = {Article}, abstract = {Three discrete carbohydrate-appended 2,2{\textquoteright}-dipicolylamine ligands were complexed to the {M(CO)3}(+) (M = Tc-99m/ Re) core: 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-D-glucopyranoside (L-1), 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-Dxylopyranoside (L-2), and 2-(bis(2-pyridinylmethyl)amino)ethyl-alpha-D-mannopyranoside (L-3). An ethylene spacer is used to separate the carbohydrate moiety and the dipicolylamine (DPA) function in all three ligands. The Re complexes [Re(L1-3)(CO)(3)]Br were characterized by H-1 and C-13 1D/2D NMR spectroscopies, which confirmed the pendant nature of the carbohydrate moieties in solution. NMR measurements also established the long-range asymmetric effect of the carbohydrate functions on the chelating portion of the ligand. One analogue, [Re(L-1)(CO)(3)]Cl, was characterized in the solid state by X-ray crystallography. Further characterization was provided by IR spectroscopy, elemental analysis, conductivity, and mass spectrometry. Radiolabeling of L-1-L-3 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded high yield compounds of identical character to the Re analogues. The radiolabeled compounds were found to be stable toward ligand exchange in the presence of a large excess of either cysteine or histidine over a 24-h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, BOMBESIN ANALOG, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, LIGANDS, PALLADIUM(II) COMPLEXES, RHENIUM CARBONYL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRIDENTATE}, isbn = {0020-1669}, url = {://000228374400020}, author = {Storr, T. and Sugai, Y. and Barta, C. A. and Mikata, Y. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1266, title = {Novel carbohydrate-appended metal complexes for potential use in molecular imaging}, journal = {Chemistry-a European Journal}, volume = {11}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 887BZTimes Cited: 27Cited Reference Count: 60}, month = {Dec}, pages = {195-203}, type = {Article}, abstract = {Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) (Tc-99m/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L-1), 1,3-diamino-2-propyl beta-D-xylopyranoside (L-2), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L-3), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L-4), 1,3diamino-2-propyl beta-D-galactopyranoside (L-5), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyrano- side) (L-6), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L-7). The Re complexes [Re((LL7)-L-1)(Br)(CO)(3)] were characterized by H-1 and C-13 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L-2)(CO)(3)Br] and [Re(L-3)(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L-1-L-7)- (H2O)(CO)(3)]Br in aqueous conditions. Radiolabelling of V-L 7 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, carbohydrates, CRYSTAL-STRUCTURES, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, molecular imaging, PALLADIUM(II) COMPLEXES, RADIOPHARMACEUTICALS, rhenium, STRUCTURAL-CHARACTERIZATION, SUGAR-PENDANT, TC-99M, technetium}, isbn = {0947-6539}, url = {://000226278700018}, author = {Storr, T. and Obata, M. and Fisher, C. L. and Bayly, S. R. and Green, D. E. and Brudzinska, I. and Mikata, Y. and Patrick, B. O. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1266, title = {Novel carbohydrate-appended metal complexes for potential use in molecular imaging}, journal = {Chemistry-a European Journal}, volume = {11}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 887BZTimes Cited: 27Cited Reference Count: 60}, month = {Dec}, pages = {195-203}, type = {Article}, abstract = {Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) (Tc-99m/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L-1), 1,3-diamino-2-propyl beta-D-xylopyranoside (L-2), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L-3), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L-4), 1,3diamino-2-propyl beta-D-galactopyranoside (L-5), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyrano- side) (L-6), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L-7). The Re complexes [Re((LL7)-L-1)(Br)(CO)(3)] were characterized by H-1 and C-13 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L-2)(CO)(3)Br] and [Re(L-3)(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L-1-L-7)- (H2O)(CO)(3)]Br in aqueous conditions. Radiolabelling of V-L 7 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, carbohydrates, CRYSTAL-STRUCTURES, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, molecular imaging, PALLADIUM(II) COMPLEXES, RADIOPHARMACEUTICALS, rhenium, STRUCTURAL-CHARACTERIZATION, SUGAR-PENDANT, TC-99M, technetium}, isbn = {0947-6539}, url = {://000226278700018}, author = {Storr, T. and Obata, M. and Fisher, C. L. and Bayly, S. R. and Green, D. E. and Brudzinska, I. and Mikata, Y. and Patrick, B. O. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1263, title = {Synthesis and reactivity of zirconium and hafnium complexes incorporating chelating diamido-N-heterocyclic-carbene ligands}, journal = {Journal of Organometallic Chemistry}, volume = {690}, number = {24-25}, year = {2005}, note = {ISI Document Delivery No.: 994VFTimes Cited: 36Cited Reference Count: 51}, month = {Dec}, pages = {5788-5803}, type = {Article}, abstract = {Early transition metal complexes employing a diamido N-heterocyclic carbene (NHC) ligand set (denoted [NCN]) render the centrally disposed NHC moiety stable to dissociation. Aminolysis reactions with the mesityl-substituted ligand precursor ((Mes)[NCN]H-2) and M(NMe2)(4) (M = Zr, Hf) provide bis(amido)-NHC-metal complexes that can be further converted to chloro and alkyl derivatives. Activation of (Mes)[NCN]M(CH3)(2) with [Ph3C][B(C6F5)(4)] yields {(Mes)[NCN]MCH3} {B(C6F5)(4)}, which is surprisingly inactive for the polymerization of 1-hexene. The zirconium cation did, however, show moderate ability to catalytically polymerize ethylene. The hafnium dialkyls are thermally stable with the exception of the diethyl complex, (Mes)[NCN]Hf(CH2CH3)(2), which undergoes P-hydrogen transfer and subsequent C-H bond activation with an ortho-methyl substituent on the mesityl group. The hafnium dialkyl complexes also insert carbon monoxide and substituted isocyanides to yield eta(2)-acyls and eta(2)-iminoacyls, respectively. In some circumstances, further C-C bond coupling occurs to yield enediolates and eneamidolate metallocycles. The molecular structures of (Mes)[NCN]Hf(CH2CHMe2)(2), (Mes)[NCN]Hf(eta(2)-(2,6-Me2C6H3NCCH3)(CH3), (Mes)[NCN]Hf(eta(2)-(2,6-Me2C6H3NCCH3)(2), (Mes)[NCN]Hf(OC(CH3)=C(CH3)NXy), and [(Mes)[NCN]Hf(OC(Bu-i)=C(Bu-i)O)](2) are included. (c) 2005 Elsevier B.V. All rights reserved.}, keywords = {AMIDO, CARBON-MONOXIDE, CHEMISTRY, DONORS, ETA-2-IMINOACYL, hafnium, LIVING POLYMERIZATION, MIGRATORY INSERTION, N-heterocyclic carbene, OLEFIN, POLYMERIZATION, PROPERTIES, SPECTROSCOPIC, STABLE CARBENES, STRUCTURAL-CHARACTERIZATION, tridentate ligand, ZIRCONIUM, ZIRCONOCENE COMPLEXES}, isbn = {0022-328X}, url = {://000234058600046}, author = {Spencer, L. P. and Fryzuk,Michael D.} } @article {775, title = {Ruthenium(II) acetylacetonato-sulfoxide complexes}, journal = {Inorganic Chemistry Communications}, volume = {6}, number = {8}, year = {2003}, note = {ISI Document Delivery No.: 707PBTimes Cited: 9Cited Reference Count: 35}, month = {Aug}, pages = {996-1000}, type = {Article}, abstract = {The water-soluble Ru-II acetylacetonato-sulfoxide complexes, cis-Ru(acac)(2)(DMSO)(2) (1) and Ru(acac)(2)(meso-BESE) (2), were synthesized (BESE = 1,2-bis(ethylsulfinyl)ethane = EtS(O)(CH2)(2)S(O)Et). Both complexes were characterized by H-1 and C-13{H-1} NMR, UV-Vis, and IR spectroscopies, as well as MS, elemental analysis, solution conductivity, and cyclic voltammetry, while the molecular structure of 2 was determined also by X-ray crystallography. All sulfoxide ligands are S-bonded. The complexes were tested against human breast cancer cells (MDA-MB-435S) using an in vitro MTT assay, a colorimetric determination of cell viability; IC50 values of >2000 and 1500 +/- 100 muM were determined for 1 and 2, respectively, while cisplatin exhibits an IC50 value of 30 +/- 5 muM. (C) 2003 Elsevier Science B.V. All rights reserved.}, keywords = {2D NMR spectroscopy, acetylacetonato, ANTITUMOR-ACTIVITY, CANCER, CHEMISTRY, COLORIMETRIC ASSAY, COORDINATION, INVITRO, PRECURSOR, ruthenium, STRUCTURAL-CHARACTERIZATION, sulfoxides, TUMOR CELL-LINES}, isbn = {1387-7003}, url = {://000184518100004}, author = {Wu, A. and Kennedy, David C and Patrick, B. O. and James, Brian R.} } @article {4726, title = {Methanol-induced conformations of myoglobin at pH 4.0}, journal = {Biochemistry}, volume = {39}, number = {47}, year = {2000}, note = {ISI Document Delivery No.: 378UETimes Cited: 62Cited Reference Count: 78}, month = {Nov}, pages = {14702-14710}, type = {Article}, abstract = {The equilibrium methanol-induced conformation changes of holomyoglobin (hMb) at pH 4.0 have been studied by circular dichroism, tryptophan fluorescence, and Soret band absorption and by electrospray ionization mass spectrometry (ESI-MS). Optical spectra show the following: (1) In 35-40\% (v/v) methanol/water, the native-like secondary structure remains, the tertiary structure is lost, the heme protein interactions are decreased, and a folding intermediate is formed. (2) In 50\% methanol, heme is lost from the protein, and there is a small decrease in helicity together with a loss of tertiary structure. (3) At > 60\% methanol, the helicity increases and the apoprotein goes into a helical denatured state. The conformations are also probed by the charge states produced in ESI-MS and by hydrogen/deuterium (H/D) exchange with mass measurement by ESI-MS. At 0-30\% methanol, native hMb produces relatively low charge states (9(+)-13(+)) in ESI-MS and exchanges relatively few hydrogens. In 35-40\% methanol, at which an intermediate is formed, there is a bimodal distribution of hMb ions with both low (9(+)-13(+)) and high (14(+)-23(+)) charge states and also a high charge state distribution (12(+)-26(+)) of apomyoglobin (aMb) ions. Low and high charge states of hMb and a high charge state of aMb all show the same H/D exchange rate, indicating that an unfolded hMb intermediate interconverts between folded hMb and unfolded aMb. The charge state distribution for the unfolded hMb intermediate observed here is similar to that of the recently reported transient intermediate formed during the acid denaturation of hMb. At 50\% alcohol the protein produces predominantly high charge states of aMb ions and shows H/D exchange rates close to those of the acid-denatured protein. H/D exchange of the helical denatured protein at alcohol concentrations >60\%, at which high charge states of aMb are produced, shows that the protein structure is more protected than at similar to 50\% methanol.}, keywords = {AMIDE HYDROGEN-EXCHANGE, APOMYOGLOBIN, BETA-LACTOGLOBULIN, CYTOCHROME-C, ELECTROSPRAY-IONIZATION, FOLDING INTERMEDIATE, IONIZATION MASS-SPECTROMETRY, MOLTEN GLOBULE INTERMEDIATE, SPERM-WHALE, STRUCTURAL-CHARACTERIZATION, X-RAY-SCATTERING}, isbn = {0006-2960}, url = {://000165602400040}, author = {Babu, K. R. and Douglas, D. J.} }