Mild template synthesis in the Cu(II)-dithiomalonamide-formaldehyde ternary system

Abstract

Complex formation in the ternary system Cu(II)-dithiomalonamide H 2NC(=S)CH2C(=S)NH2-formaldehyde in aqueous ethanol containing copper(II) chloride, dithiomalonamide and formaldehyde, as well as in thin-layer gelatin-immobilized copper(II) hexacyanoferrate(II) matrix implants contacting with alkaline (pH > 10) aqueous solutions containing the same organic compounds was studied. In the first case, a Cu(II) bischelate complex with singly deprotonated dithiomalonamide is formed exclusively, whereas in the second case template synthesis occurs to form a macrocyclic CuL chelate (L is 1,11-diamino-1,11-disulfanyl-4,8-diaza-6-oxaundeca-1,10-diene-3,9- dithione). In the latter case, dithiomalonamide and formaldehyde function as ligsons. The above-mentioned chelate is not formed on direct contact of the reagents in aqueus ethanol both in the presence and in the absence of Cu(II). A scheme of chemical reactions that occur in the system under consideration was proposed. © 2008 MAIK Nauka.