Synthesis, structure and reactions of a series of 1,2-dicyanoethylenedithiolate coordinated dimeric Mo(V) complexes

摘要

[Bu4N](2) [(Mo2O4)-O-V (mnt)(2)] (where mnt = 1,2-dicyanoethylenedithiolate) (1), reacts with HX (X = SPh, Cl, Br) to form a series of complexes, [Bu4N](2)[(Mo2O3)-O-v(mnt)(2)(L)(2)] (L = SPh (2a), Cl (2b), Br (2c)). In acidic-alcoholic medium 1 with thiophenol yields another series of compounds, [Bu4N] [(Mo2O2)-O-V(mnt)(2)(mu-SPh)(2)(mu-OY)] (Y = Me (3a), Et (3b), Pr-i (3c)). Under similar conditions tertiary-butanol does not coordinate where a complex can only be isolated in the presence of bromide as [Bu4N](2)[(Mo2O2)-O-V(mnt)(2)(mu-O)(mu-SPh) (mu-Br)] (4). The use of excess of methanesulfonic acid in the presence of HSPh or HSEt facilitates methanesulfonate coordination in complexes, [Bu4N](2)[(Mo2O2)-O-V(mnt)(2)(mu-O)(mu-SZ)(mu-CH3SO3)] (Z =Ph (5), Et (6)). All these complexes are structurally characterized by single crystal X-ray study. These complexes show pH dependent hydrolytic reaction leading to quantitative reversal to the starting complex, 1. Complexes 2a-c respond to hydrolysis in CH2Cl2 with the intermediate formation of EPR active molybdenum(V) species. (c) 2007 Elsevier B.V. All rights reserved.