Gallium(III) complexes based on N,N′-bis(salicylidene)propane-1,3-diamine and its derivatives

Abstract

The reactions of N,N′-bis(salicylidene)propane-1,3-diamine (salpropH2) and its substituted derivatives with Ga(acac)3 afforded the complexes [Ga(acac)(salprop)]·0.5H2O (1), [Ga(acac)(5Clsalprop)] (2), [Ga(acac)(5Brsalprop)] (3), [Ga(acac)(5NO2salprop)] (4) and [Ga(acac)(5Mesalprop)] (5), in high yields. The crystal structures of all complexes have been determined by single-crystal X-ray crystallography. All complexes are mononuclear with the Ga(III) atoms being in octahedral environments surrounded by one tetradentate chelate 5Rsalprop2− ligand and one bidentate chelate acac− ligand. The free ligands exhibit photoluminescence which was found to be increased upon complex formation. The substituted derivatives of the salpropH2 ligand bearing either electron-donating methyl groups or electron-withdrawing groups, such as Cl, Br and NO2 at the fifth position of both salicylidene rings were found to modify the emission maximum of the free ligands and the complexes.