Studies on nickel(II) complexes. VII. a nuclear resonance investigation of mixed ligand complexes

Abstract

Equilibration of solutions of differently substituted bis(salicylaldimine)-Ni(II) complexes which are involved in a planar tetrahedral conformational equilibrium results in rapid and nearly statistical ligand exchange The mixed ligand complexes thus produced have been unambiguously identified by their proton resonance spectra which, like these of the pure complexes, exhibit characteristic isotropic proton hyperfine contact interactions. Spin densities in the mixed complexes have been measured, and comparison with the pure complexes shows that an asymmetric redistribution of spin has occurred A recent model for the production of asymmetric spin density distributions is applied to the mixed salicyladimine complexes A Probable Mechanism for the ligand-exchange process is discussed.