Complexes of cobalt, nickel, zinc and cadmium with riboflavin in acetonitrile

Using the methods of solubility, electron and IR spectroscopy, the composition, stability and structure of cobalt, nickel, zinc and cadmium complexes with riboflavin (RF) in acetonitrile at the background of 1 mol/l LiClO4x3H2O are determined. It is shown, that the metals studied form low-stable complexes with RF (K1 approximately 10-20), in with metal is bound with RF molecule via oxygen atom. It is detected, that cadmium and, to a lower degree zinc, cobalt and nickel, have a tendency for the formation of more complex compounds with RF. Totality of the experimental data obtained suggests the formation of (MRF)sub(2)sup(4+) associates