Spectroscopic and ODMR investigations of the lowest ππ* and ligand-ligand charge-transfer excited states of zinc(II) mixed-ligand complexes

Abstract

Zero-field splittings of the emitting levels of the title compounds were measured by ODMR. For complexes of the type Zn(X-PhS)2(phen) resonances of the3ππ* phosphorescing levels were observed for X=F5, 4-Cl, 4-CH3. For X=4-Cl, resonances were detected for the3LLCT emitting manifold also. For X=4-CH3O, resonances were detected only for the3LLCT emitting states. A model invoking mixing between the two types of states is proposed that satisfactorily accounts for the dependences of the properties of the emitting manifolds on the donating ability of the X substituent.