Syntheses, structures, photoluminescence, and theoretical studies of a novel class of d10 metal complexes of 1H-[1,10]phenanthrolin-2-one

A novel asymmetric monosubstituted 1,10-phenanthroline, Hophen.0.5H(2)O (1, Hophen = 1H-[1,10]phenanthrolin-2-one), was generated by a facile route, and a novel class of crystalline, d(10)-metal, monomeric or oligomeric complexes of this ligand, namely [Hg(ophen)(2)].4H(2)O.CH2Cl2 (2), [Cd3Cl(ophen)(5)].1.5H(2)O.2CH(2)Cl(2) (3), and [Zn4O(ophen)(4)(OAc)(2)]-4H(2)O. 2 CH2Cl2 (4), were obtained by means of liquid diffusion, and were characterized by X-ray crystallography and photoluminescence studies. Complex 1 exhibits a hydrogen-bonded dimeric structure, 2 is a neutral monomeric complex, 3 has a trinuclear structure with the ophen ligand acting as a bridge through the ketone groups, and 4 features a tetranuclear Zn4O core that is consolidated further by bridging ophen and acetate ligands. All the complexes display photoluminescent properties in the blue/ green region. The photoluminescent mechanisms were investigated by means of molecular orbital calculations, which showed that the photoluminescent properties are ligand-based and can be tuned upon ligation to different metal ions.