Transmetalation of targets (μ-Y)N 4Cu 2ICu 2IICl 4 and (μ-Y,/μ-O)N 4Cu 4Cl 4 (Y=3,4,5,6-tetrachlorocatecholate) with M(NS) 2 reagents

Abstract

The copper(I) molecule [NCuCl] 4 (N is monodentate N,N-diethylnicotinamide) reacts with one and two moles of 3,4,5,6-tetrachloro-l,2-benzoquinone, Cl 4BQ, in methylene chloride to give (μ -Y)N 4Cu 2 I(Cu 2 IICl 4 (C) and (μ-Y) 2N 4Cu 4Cl 4 ( E), respectively, where Y is 3,4,5,6-tetrachlorocatecholate. E is converted to (μ-Y)N 4Cu 2(Cu(OH)) 2Cl 4 ( F) by reaction with water. Target C reacts with O 2 to give (μ-Y,μ-O)N 4Cu 4Cl 4 ( D), which has distinct copper(II) sites. Reaction of C with equimolar S-methyl isopropylidenehydrazinecarbodithioate transmetalators M(NS) 2 (A(M), with M  Co, Ni and Zn in A(Co), A(Ni) and A(Zn), respectively) results in specific copper(I) transmetalation to give (μ-Y)N 4Cu 2 IICu IM(NS)Cl 4 that react with O 2 to give (μ-Y,μ-O)N 4Cu 3MCl 4 ( III). The same products III are obtained by transmetalation of 1D with equimolar A( M). Progressive transmetalation of D with 2, 3 and 4 moles of A(Ni) gives particular isomers of the heteropolymetallic family (μ-Y,μ-O)N 4Cu 4− x (Ni(H 2O)) x Cl 4, x=0–4, evidently due to the trans-directing influence of bridging Y and oxo target groups. Direct transmetalation and isomerization/transmetalation reaction sequences that would give these products are deduced from an ‘additive dimer’ spectral analysis.