Structure, Equilibrium and Ribonuclease Activity of Copper(II) and Zinc(II) Complexes Formed with a Dinucleating Bis-Imidazole Ligand

Highly Efficient Phosphodiester Hydrolysis Promoted by a Dinuclear Copper(II) Complex

“…Because of the constraints caused by the fused five-membered chelate rings of the ligand backbone, both the Cu−Cu distances and Cu−O−Cu angles in the alkoxo-bridged units are higher (3.627(2)−3.782(3) Å and 136−138.7°, respectively). These values are within the range observed for similar μ-dihydroxo-bridged and μ-alkoxo-bridged dinuclear copper(II) complexes. The Cu−Cu separations between the nonbridged metal ions are 5.455(3)−5.712(3) Å.…”

Highly Efficient Phosphodiester Hydrolysis Promoted by a Dinuclear Copper(II) Complex

“…Because of the constraints caused by the fused five-membered chelate rings of the ligand backbone, both the Cu−Cu distances and Cu−O−Cu angles in the alkoxo-bridged units are higher (3.627(2)−3.782(3) Å and 136−138.7°, respectively). These values are within the range observed for similar μ-dihydroxo-bridged and μ-alkoxo-bridged dinuclear copper(II) complexes. The Cu−Cu separations between the nonbridged metal ions are 5.455(3)−5.712(3) Å.…”

Nucleophilic reaction by carbonic anhydrase model zinc compound: characterization of intermediates for CO2 hydration and phosphoester hydrolysis

“…The observed sigmoidal pH dependence of k 2 was similar to a number of phosphoester hydrolyses promoted by many different zinc model compounds [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]; the inflection point (pH 8.6) of a sigmoidal curve was close to the determined pK a ¼ 8:4 by pH titration method.…”

La3+-Catalyzed Methanolysis of Hydroxypropyl-p-nitrophenyl Phosphate as a Model for the RNA Transesterification Reaction

“…At a 1:1 ratio, where there are only two prominent 31 P NMR signals at δ −8.9 and −15.5, we suggest that the 1:1 and 2:2 complexes dominate. While at this time we are not sure which complex is assigned to a given chemical shift, the approximate 6.5 ppm separation for the 31 P signals is consistent with the known chemical shift differences of bridging phosphates relative to monodentate-coordinated phosphates in related Co III complexes. 11g, At room temperature, all species are in dynamic equilibrium on the NMR time scale.…”

Highly Efficient Phosphodiester Hydrolysis Promoted by a Dinuclear Copper(II) Complex

“…Because of the constraints caused by the fused five-membered chelate rings of the ligand backbone, both the Cu−Cu distances and Cu−O−Cu angles in the alkoxo-bridged units are higher (3.627(2)−3.782(3) Å and 136−138.7°, respectively). These values are within the range observed for similar μ-dihydroxo-bridged and μ-alkoxo-bridged dinuclear copper(II) complexes. The Cu−Cu separations between the nonbridged metal ions are 5.455(3)−5.712(3) Å.…”

Nucleophilic reaction by carbonic anhydrase model zinc compound: characterization of intermediates for CO2 hydration and phosphoester hydrolysis

“…The observed sigmoidal pH dependence of k 2 was similar to a number of phosphoester hydrolyses promoted by many different zinc model compounds [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]; the inflection point (pH 8.6) of a sigmoidal curve was close to the determined pK a ¼ 8:4 by pH titration method.…”

La3+-Catalyzed Methanolysis of Hydroxypropyl-p-nitrophenyl Phosphate as a Model for the RNA Transesterification Reaction

“…At a 1:1 ratio, where there are only two prominent 31 P NMR signals at δ −8.9 and −15.5, we suggest that the 1:1 and 2:2 complexes dominate. While at this time we are not sure which complex is assigned to a given chemical shift, the approximate 6.5 ppm separation for the 31 P signals is consistent with the known chemical shift differences of bridging phosphates relative to monodentate-coordinated phosphates in related Co III complexes. 11g, At room temperature, all species are in dynamic equilibrium on the NMR time scale.…”

Highly Efficient Phosphodiester Hydrolysis Promoted by a Dinuclear Copper(II) Complex

“…Because of the constraints caused by the fused five-membered chelate rings of the ligand backbone, both the Cu−Cu distances and Cu−O−Cu angles in the alkoxo-bridged units are higher (3.627(2)−3.782(3) Å and 136−138.7°, respectively). These values are within the range observed for similar μ-dihydroxo-bridged and μ-alkoxo-bridged dinuclear copper(II) complexes. The Cu−Cu separations between the nonbridged metal ions are 5.455(3)−5.712(3) Å.…”

Nucleophilic reaction by carbonic anhydrase model zinc compound: characterization of intermediates for CO2 hydration and phosphoester hydrolysis

“…The observed sigmoidal pH dependence of k 2 was similar to a number of phosphoester hydrolyses promoted by many different zinc model compounds [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]; the inflection point (pH 8.6) of a sigmoidal curve was close to the determined pK a ¼ 8:4 by pH titration method.…”

La3+-Catalyzed Methanolysis of Hydroxypropyl-p-nitrophenyl Phosphate as a Model for the RNA Transesterification Reaction

“…At a 1:1 ratio, where there are only two prominent 31 P NMR signals at δ −8.9 and −15.5, we suggest that the 1:1 and 2:2 complexes dominate. While at this time we are not sure which complex is assigned to a given chemical shift, the approximate 6.5 ppm separation for the 31 P signals is consistent with the known chemical shift differences of bridging phosphates relative to monodentate-coordinated phosphates in related Co III complexes. 11g, At room temperature, all species are in dynamic equilibrium on the NMR time scale.…”