Reinvestigation of Decarboxylation Kinetics from the Hydrogencarbonatocobalt(III) Intermediate
作者:Yoichi Kitamura、Leona Yano、Kazuya Fujimori、Ryuji Mizuki、Masayuki Hayashi、Akira Shibata
DOI:10.1246/bcsj.73.2025
日期:2000.9
Acid-catalysed hydrolysis has been studied by a stopped-flow method at 25 °C, ionic strength of 2.0 (NaClO4) and oxonium ion concentration of 0.02—1.0 M for monodentate carbonato complexes ( [Co(CO3)(NH3)5]+, [Rh(CO3)(NH3)5]+, and [Ir(CO3)(NH3)5]+) and for didentate carbonato complexes ( [Co(CO3)(NH3)4 ]+, [Co(CO3)(en)2]+, α, β-[Co(CO3)(trien)]+, [Co(CO3)(tren) ]+ and [Co(CO3)(nta)]2- (M = mol dm-3, en = ethylenediamine
在 25 °C、离子强度为 2.0 (NaClO4) 和氧鎓离子浓度为 0.02-1.0 M 的单齿碳酸根络合物 ([Co(CO3)(NH3)5]+ , [Rh(CO3)(NH3)5]+, 和 [Ir(CO3)(NH3)5]+) 和双齿碳酸根络合物 ([Co(CO3)(NH3)4 ]+, [Co(CO3)( en)2]+, α, β-[Co(CO3)(trien)]+, [Co(CO3)(tren) ]+ 和 [Co(CO3)(nta)]2- (M = mol dm-3 ,en = 乙二胺,trien = 1,8-二氨基-3,6-二氮杂辛烷,tren = 三(2-氨基乙基)胺,并且 H3nta = 次氮基三乙酸))。从单齿碳酸氢中间体脱羧的实验一级速率常数取决于溶液的酸度,我们将其归因于其两性特性。去质子化常数关键取决于与碳酸氢根配体顺式的水配体:0.004-0.6 M,而没有它大约 10-6