Study on the Photoluminescent and Thermal Properties of Zinc Complexes with a N(6)O(4) Macrocyclic Ligand

Reactions between a N(6)O(4) macrocyclic ligand (L(1)) and several Zn(II) salts (trifluoromethane sulfonate, p-toluenesulfonate, acetate, benzoate, o-, m- or p-hydroxybenzoate) led to the formation of seven complexes, [Zn(2)L(1) (DMSO)(4)](OSO(2)CF(3))(4) (1), [Zn(2)(p-OSO(2)PhCH(3))(4)L(1)] (2), [Zn(2)(OCOCH(3))(4)L(1)] (3), [Zn(2)(OCOPh)(4)L(1)] (4), [Zn(2)(o-OCOPhOH)(4)L(1)] (5), [Zn(2)(m-OCOPhOH)(4) L(1)] (6) and [Zn(2)(p-OCOPhOH)(4) L(1)] (7), which were characterized by elemental analysis, (1)H-NMR, (13)C-NMR, IR, fluorescence spectroscopies and single crystal X-ray diffraction. In 1, the Zn atom is pentacoordinated with a N(3)O(2) irregular trigonal bipyramidal coordination environment, like the geometries in compounds 3–7, whereas in structure 2 the metal atom is envisaged as possessing a distorted N(3)O(3) octahedronal environment. All the compounds show interesting photoluminescent properties in solid states and solutions in DMF and DMSO, which are reported along with their TG-DTA thermal decomposition processes, UV-vis absorption spectroscopy and fluorescence quantum yields in DMF and DMSO.