The thermochemistry of some acetonitrile and benzonitrile complexes of transition-metal halides

Abstract

The heats of decomposition of acetonitrile and benzonitrile complexes of the type ML_nX_m(M = Mn, Co, Ni, Rh, Pd, Ir, and Pt; X = halide or thiocyanate) were measured by differential scanning calorimetry and indicate that some π-bonding may occur. Steric effects were found to be operative in the cis-complexes of acetonitrile and benzonitrile with palladium and platinum, and mer-Rh(MeCN)₃Cl₃ was more stable than the fac-isomer by 16·5 kJ mol^–1.