Asymmetric halogeno-bridged complexes of the late transition metals - A computational and experimental study

Abstract

Metathesis reactions of dinuclear halo-bridged complexes of the late transition metals have been studied by NMR. For selected combinations of 15 different complexes, it has been shown that asymmetric complexes are formed in a dynamic equilibrium. The equilibrium constants have been calculated and the trends therein are discussed. A theoretical analysis of halo-bridged complexes containing (C3H5)MX, (H3P)MX2, [(H3P)2MX]+, and (ppy)2RhCl fragments (M =Pd, Pt; X = Cl, Br, I; ppy = anion of 2-phenylpyridine) has been carried out to gain further insight into (i) the influence of the bridging halogen atoms on the equilibrium, (ii) the electron transfer, (iii) the thermodynamic stability and the dynamic equilibrium behaviour, and (iv) structural differences between symmetric and asymmetric halo-bridged complexes.