Disproportionation of aquachromyl(IV) ion by hydrogen abstraction from coordinated water

被引:23
作者
Nemes, A [1 ]
Bakac, A [1 ]
机构
[1] Iowa State Univ, Ames Lab, Ames, IA 50011 USA
关键词
D O I
10.1021/ic0013577
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
In aqueous solutions, the aquachromyl(IV) ion, CraqO2+, disproportionates to Cr-aq(3+) and HCrO4-. The reaction exhibits second-order kinetics with an inverse [H+] dependence, -d[CraqO2+]/dt = 38.8[CraqO2+](2)[H+](-1) at 25 degreesC. The combination of the rate law and substantial kinetic isotope effect, k(H)/k(D) = 6.9, suggests a mechanism whereby a hydrogen atom is abstracted from a coordinated molecule of water or hydroxo group within a singly deprotonated transition state. The buildup of chromate is more complicated and somewhat slower than the loss of chromyl, suggesting the involvement of intermediates.
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收藏
页码:2720 / 2724
页数:5
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