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Daniela Gerlach - One of the best experts on this subject based on the ideXlab platform.
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uranyl and transition metal Chelates of tenoxicam crystal structures of trans trans co ii hten 2 dmso 2 trans trans zn ii hten 2 dmso 2 and cis cis uo2 vi hten 2 h2o 2c2h5oh
Journal of Coordination Chemistry, 2008Co-Authors: Nadia E A Elgamel, Daniela GerlachAbstract:The synthesis and characterization of ternary Fe(III)- (1), Co(II)- (2), Ni(II)- (3), Cu(II)- (4), Zn(II)- (5) and UO2(VI)- (6) Chelates with the potent anti-inflammatory drug tenoxicam (H2ten) and (dl-alanine, Hala) are reported. All complexes are octahedral except Cu(II) and Zn(II) Chelates, which are tetrahedral, and U-atoms in the uranyl Chelates have a pentagonal-bipyramidal coordination sphere. The ternary Co(II) and Zn(II) complexes dissociate in dmso where orange and yellow crystals of trans,trans-[Co(II)(Hten)2(dmso)2] (8) and trans,trans-[Zn(II)(Hten)2(dmso)2] (9), respectively, were obtained. Crystallization of the binary uranyl Chelate (7) from ethanol afforded the ethanol solvate cis,cis-[UO2(VI)(Hten)2(H2O)] · 2C2H5OH (7a). trans,trans-[Co(II)(Hten)2(dmso)2] (8) and trans,trans-[Zn(II)(Hten)2(dmso)2] (9) crystallize in the monoclinic space group P21/n while 7a crystallizes in the triclinic space group . The kinetics of the thermal decompositions for 1, 3, 4, 6 and 7 were studied and the ther...
Nadia E A Elgamel - One of the best experts on this subject based on the ideXlab platform.
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uranyl and transition metal Chelates of tenoxicam crystal structures of trans trans co ii hten 2 dmso 2 trans trans zn ii hten 2 dmso 2 and cis cis uo2 vi hten 2 h2o 2c2h5oh
Journal of Coordination Chemistry, 2008Co-Authors: Nadia E A Elgamel, Daniela GerlachAbstract:The synthesis and characterization of ternary Fe(III)- (1), Co(II)- (2), Ni(II)- (3), Cu(II)- (4), Zn(II)- (5) and UO2(VI)- (6) Chelates with the potent anti-inflammatory drug tenoxicam (H2ten) and (dl-alanine, Hala) are reported. All complexes are octahedral except Cu(II) and Zn(II) Chelates, which are tetrahedral, and U-atoms in the uranyl Chelates have a pentagonal-bipyramidal coordination sphere. The ternary Co(II) and Zn(II) complexes dissociate in dmso where orange and yellow crystals of trans,trans-[Co(II)(Hten)2(dmso)2] (8) and trans,trans-[Zn(II)(Hten)2(dmso)2] (9), respectively, were obtained. Crystallization of the binary uranyl Chelate (7) from ethanol afforded the ethanol solvate cis,cis-[UO2(VI)(Hten)2(H2O)] · 2C2H5OH (7a). trans,trans-[Co(II)(Hten)2(dmso)2] (8) and trans,trans-[Zn(II)(Hten)2(dmso)2] (9) crystallize in the monoclinic space group P21/n while 7a crystallizes in the triclinic space group . The kinetics of the thermal decompositions for 1, 3, 4, 6 and 7 were studied and the ther...
Pamela M. Guy - One of the best experts on this subject based on the ideXlab platform.
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Bioconjugation with stable luminescent lanthanide(III) Chelates comprising pyridine subunits
Bioconjugate Chemistry, 2009Co-Authors: Jari Hovinen, Pamela M. GuyAbstract:The use of long-lifetime emitting lanthanide(III) Chelate labels or probes together with time-resolved fluorometry in detection provides a method to generate sensitive bioaffinity assays. However, the use of stable Chelates demands very complicated optimization of the Chelate structure. A great number of Chelates have been synthesized, but usually, only the most prominent structures were then converted to corresponding biomolecule labeling reactants. This review covers the syntheses of luminescent lanthanide Chelates comprising a pyridine subunit that allow solution and solid-phase bioconjugation.
Maurice Brookhart - One of the best experts on this subject based on the ideXlab platform.
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nickel catalyzed copolymerization of ethylene and vinyltrialkoxysilanes catalytic production of cross linkable polyethylene and elucidation of the chain growth mechanism
Journal of the American Chemical Society, 2017Co-Authors: Zhou Chen, Mark D Leatherman, Olafs Daugulis, Maurice BrookhartAbstract:Copolymerizations of ethylene with vinyltrialkoxysilanes using cationic (α-diimine)Ni(Me)(CH3CN)+ complexes 4a,b/B(C6F5)3 yield high molecular weight copolymers exhibiting highly branched to nearly linear backbones depending on reaction conditions and catalyst choice. Polymerizations are first-order in ethylene pressure and inverse-order in silane concentration. Microstructural analysis of the copolymers reveals both in-chain and chain-end incorporation of −Si(OR)3 groups whose ratios depend on temperature and ethylene pressure. Detailed low-temperature NMR spectroscopic investigations show that well-defined complex 3b (α-diimine)Ni(Me)(OEt2)+ reacts rapidly at −60 °C with vinyltrialkoxysilanes via both 2,1 and 1,2 insertion pathways to yield 4- and 5-membered Chelates, respectively. Such Chelates are the major catalyst resting states but are in rapid equilibrium with ethylene-opened Chelates, (α-diimine)Ni(R)(C2H4)+ complexes, the species responsible for chain growth. Chelate rearrangement via β-silyl el...
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reactions of vinyl acetate and vinyl trifluoroacetate with cationic diimine pd ii and ni ii alkyl complexes identification of problems connected with copolymerizations of these monomers with ethylene
Journal of the American Chemical Society, 2005Co-Authors: Scott B Williams, Mark D Leatherman, Peter S White, Maurice BrookhartAbstract:Vinyl acetate (VA) and vinyl trifluoroacetate (VAf) react with [(N∧N)Pd(Me)(L)][X] (M = Pd, Ni, (N∧N) = N,N‘-1,2-acenaphthylenediylidene bis(2,6-dimethyl aniline), Arf = 3,5-trifluoromethyl phenyl, L = ArfCN, Et2O; X = B(Arf)4-, SbF6-) to form π-adducts 3 and 5 at −40 °C. Binding affinities relative to ethylene have been determined. Migratory insertion occurs in a 2,1 fashion (ΔG⧧ = 19.4 kcal/mol, 0 °C for VA, and 17.4 kcal/mol, −40 °C for VAf) to yield five-membered Chelate complexes [(N∧N)Pd(κ2-CH(Et)(OC(O)CH3))]+, 4, and [(N∧N)Pd(κ2-CH(Et)(OC(O)CF3))]+, 6. When VA is added to [(N∧N)Ni(CH3)]+, an equilibrium mixture of an η2 olefin complex, 8c, and a κ-oxygen complex, 8o, results. Insertion occurs from the η2 olefin complex, 8c (ΔG⧧ = 15.5 kcal/mol, −51 °C), in both a 2,1 and a 1,2 fashion to generate a mixture of five- and six-membered Chelates, 92,1 and 91,2. VAf inserts into the Ni−CH3 bond (−80 °C) to form a five-membered Chelate with no detectable intermediate. Thermolysis of the Pd Chelates result...
Mingqian Tan - One of the best experts on this subject based on the ideXlab platform.
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synthesis and evaluation of nanoglobular macrocyclic mn ii Chelate conjugates as non gadolinium iii mri contrast agents
Bioconjugate Chemistry, 2011Co-Authors: Mingqian Tan, Eun Kee Jeong, Dennis L ParkerAbstract:Because of the recent observation of the toxic side effects of Gd(III) based MRI contrast agents in patients with impaired renal function, there is strong interest on developing alternative contrast agents for MRI. In this study, macrocyclic Mn(II) Chelates were conjugated to nanoglobular carriers, lysine dendrimers with a silsesquioxane core, to synthesize non-Gd(III) based MRI contrast agents. A generation 3 nanoglobular conjugate of Mn(II)-1,4,7-triaazacyclononane-1,4,7-triacetate-GA amide (G3-NOTA-Mn) was also synthesized and evaluated. The per ion T1 and T2 relaxivities of G2, G3, G4 nanoglobular Mn(II)-DOTA monoamide conjugates decreased with increasing generation of the carriers. The T1 relaxivities of G2, G3, and G4 nanoglobular Mn(II)-DOTA conjugates were 3.3, 2.8, and 2.4 mM–1 s–1 per Mn(II) Chelate at 3 T, respectively. The T1 relaxivity of G3-NOTA-Mn was 3.80 mM–1 s–1 per Mn(II) Chelate at 3 T. The nanoglobular macrocyclic Mn(II) Chelate conjugates showed good in vivo stability and were readil...