THE COMPARATIVE ACTIVITY CHARACTERISTICS OF HOMOGENEOUS CATALYSTS FORHYDROLYSIS OF DICYAN TO OXAMIDE

Kinetics of dicyan (DC) hydrolysis to oxamide (OA) [GRAPHICS] in the p resence of homogeneous catalysts based on 9.26 - 11.4 M solutions of h ydrochloric acid and 0.01 M solutions of Cu(NO3)2 . 3H2O in 6.98 - 15. 98 M acetic acid (AA) is investigated. The kinetic data are in good ag reement with the suggestion that mineral acids are active catalysts du e to their ability to provide protons for the N-H bond formation with a nitrogen atom of DC. In this case, activation of a nitrile group of DC is likely to proceed with the participation of a complex H2O . 2HCl for the system HCl-H2O (I), and dimeric structures [GRAPHICS] for the systems Cu(II)-AA-H2O (II). The equilibrium constants are presented f or the formation of copper acetate complexes in the presence of compet itive ligands, which may be used as a criterion of the ability of ion ligands to compete for the coordination sites of Cu(II) complexes in c oncentrated solutions of AA.