Mild Template Synthesis of (2,8-Dithio-3,7-diaza-4,6-dimethyl-5-oxanonanedithioamido-1,9)copper(II) in Cu2[Fe(CN)6] Gelatin-Immobilized Matrices

Complexation process in Cu₂(Fe(CN)₆] gelatin-immobilized matrices in contact with aqueous solutions of dithiooxamide H₂N–C(S)–C(S)–NH₂ and ethanal H₃C–CHO at pH > 10 were studied. The template synthesis was shown to occur under these specific conditions to yield the Cu(II) chelate with tetradentate (N,N,S,S)-ligand (2,8-dithio-3,7-diaza-4,6-dimethyl-5-oxanonanedithioamide-1,9) with a metal : ligand ratio of 1 : 1. Dithiooxamide and ethanal therein act as ligand syntones. The reaction scheme was suggested. It was established that this tetradentate ligand is not formed in the absence of Cu(II) in a solution in contact with the matrix. Moreover, the attempts made to obtain the title compound through the reactions of known copper(II) dithiooxamide complexes with ethanal failed.