Please use this identifier to cite or link to this item:
http://nopr.niscpr.res.in/handle/123456789/18062| Title: | Coenzyme B12 model studies: Equilibria and kinetics of axial ligation of alkyl(aquo)cobaloximes by N donor ligands |
| Authors: | Reddy, D Sudarshan Rao, B Krishna Pallavi, P Navaneetha, N Satyanarayana, S |
| Issue Date: | Apr-2005 |
| Publisher: | NISCAIR-CSIR, India |
| IPC Code: | Int Cl.7 C07F 15/06 |
| Abstract: | Equilibria and kinetics of the reaction of trifluoroethyl(aquo)cobaloxime and iodomethyl(aquo)cobaloxime with histamine, histidine, glycine and ethyl glycine ester have been studied as a function of pH at 25°C, 1.0M KCI ionic strength by spectrophotometry technique. Comparison of equilibrium constants and rate constants indicates that the order is KHisn>KHiamn> KGly>KGiyest· The rate of substitution of H2O varies with the pKa of the incoming ligand establishing the existence of nucleophilic participation of the ligand in the transition state. The rate constants and equilibrium constants are correlated to the hardness and softness of the ligands and Co(III) of cobaloxime. Triflouroethyl(aquo)cobaloxime forms more stable complexes than iodomethyl(aquo)cobaloxime. |
| Page(s): | 678-686 |
| ISSN: | 0975-0975(Online); 0376-4710(Print) |
| Appears in Collections: | IJC-A Vol.44A(04) [April 2005] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJCA 44A(4) 678-686.pdf | 1.69 MB | Adobe PDF | View/Open |
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