From cadmium(II)-aroylhydrazone complexes to metallopolymers with enhanced photoluminescence. A structural and DFT study

Reaction of cadmium(II) acetate and donor-acceptor conjugated O,N,O ligands led to complexes with coordinated pyridine and to polymeric materials by grafting onto poly(4-vinylpyridine). All the synthesized compounds exhibited luminescent properties. Two ligands series with and without a bulky end group produced molecular structures with a dinuclear arrangement. Structural and photophysical properties were systematically explored and compared to previously reported zinc complexes. Benzothiazole containing ligands revealed a new coordination mode with respect to zinc. Quantitative emission measurements were performed on solid samples of complexes and polymers. Differences of photoluminescence quantum yields in molecular complexes and grafted polymers were revealed. Experimental absorption and emission data were explained by theoretical calculations on crystalline and insulated models.