Spontaneous and base-catalyzed nitrito to nitro linkage isomerization of trans-[Co(NH3)4(NH2CH3)ONO]2+ complex

被引：4

作者：

Bozoglian, F ^{[1
]}

Queirolo, M ^{[1
]}

Sienra, B ^{[1
]}

机构：

[1] Fac Quim Montevideo, Montevideo, Uruguay

来源：

POLYHEDRON | 1998年 / 17卷 / 20期

关键词：

nitrito ion; nitro linkage isomerization; pentaamminecobalt(III) complexes;

D O I：

10.1016/S0277-5387(98)00148-X

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The nitrito ion trans-[Co(NH3)(4)(NH2CH3)ONO](2+) rearranges to its nitro form trans-[Co(NH3)(4) (NH2CH3)NO2](2+) in aqueous base according to the rate law k(obs) = k(s) + k(bc)[OH-]. At mu = 1.0 M, 25 degrees C k(s) = 1.01 x 10(-4) s(-1) Delta H-s* = 98 kJ mol(-1); Delta S-s* = 7 JK(-1); k(bc) = 3.3 x 10(-2) M(-1)s(-1); Delta H-bc* = 121 kJ mol(-1); Delta S-bc* = 132 JK(-1) mol(-1). The base-catalyzed isomerization proceeds enterely via an intramolecular conjugate-base mechanism. The reaction is fully retentive and trans-[Co(NH3)(4)(NH2CH3)NO2](2+) is the only species that could be detected by H-1 nmr after the reaction was completed. The results are discussed in the light of the reaction mechanisms proposed so far and in relation to the normal substitution chemistry of pentaammine-cobalt(III) complexes. (C) 1998 Elsevier Science Ltd. All rights reserved.

引用

页码：3551 / 3556

页数：6