Solvent exchange, solvent interchange, aquation and isomerisation reactions of cis- and trans-[Co(tmen)2(NCMe)2]3+ in water, Me2SO and MeCN: kinetics and stereochemistry
作者:W.Gregory Jackson、A.F.M.Mokhlesur Rahman、M.Anthony Wong
DOI:10.1016/j.ica.2003.05.010
日期:2004.2
product; cis reactant – 99% cis product. Aquation rates for cis- and trans-[Co(tmen)2(NCCH3)2](ClO4)3 have also been determined spectrophotometrically and by NMR; kcis=1.3 × 10−4 and ktrans=2.7 × 10−5 s−1. In both cases the steric course for the primary aquation step is indeterminate because the subsequent steps are faster. Where data are available, the [Co(tmen)2X2]n+ complexes are found to be consistently
描述了顺式和反式-[Co(tmen)2(NCCH 3)2 ](ClO 4)3的合成和表征。已通过1 H NMR光谱和UV-Vis分光光度法在298.2 K的二甲基亚砜中测量了溶剂分解速率。顺式异构体通过连续的一级反应经历了溶剂分解,k 1 = 5.61×10 -4和k 2 = 5.35×10 -4 s -1,每个都具有空间保留。反式的测得的溶剂分解速率(单步反应)异构体为k= 1.54×10 -5 s -1。溶剂交换速率已通过1 H NMR光谱在CD 3 CN中以298.2 K进行了测量:k ex(顺式)= k ct + k cc = 2.0×10 -5,并且k ex(trans)= k tc + k tt = 4.56×10 -6 s -1。根据这些数据,测得的顺式-反式异构化速率为(1.71×10 -6 s-1)和CH 3 CN中的平衡位置(17%反式),确定了交换过程中取代的空间过程:反式反应物–