Heteronuclear coordination compounds of copper and cobalt in urethane-yielding reactions

Heteronuclear coordination compounds capable of catalyzing the low-temperature dissociation of urethane groups were synthesized on the basis of copper and cobalt chlorides. The study was performed with an urethane prepolymer produced from oligoester diol and 2,4-toluylene diisocyanate. It was found that the dissociation of urethane groups in the prepolymer is accompanied by formation of carbodiimides and release of 2,4-toluylene diisocyanate. As a result of the subsequent redox interaction, Cu(II) ions are mostly converted to Cu(I), and the involvement of isocyanate groups in the para-position into the reaction processes leads to formation of azoaromatic derivatives. It is shown that their coordination binding by Co(II) ions strongly affects both the supramolecular organization of polyurethanes and a set of their physicomechanical properties.