Synthesis, characterization, photoluminescent and thermal properties of zinc(ii) 4′-phenyl-terpyridine compounds

Reactions between 4′-phenyl-terpyridine (L) and several Zn(II) salts (trifluoromethane sulfonate, p-toluenesulfonate, benzoate, p-hydroxybenzoate, o-hydroxybenzoate or m-hydroxybenzoate) led to the formation of the complexes [Zn(OSO2CF3)2L(H2O)] (1), [Zn(p-OSO2PhCH3)2L] (2), [Zn(OCOPh)2L] (3), [Zn(p-OCOPhOH)2L] (4), [Zn(o-OCOPhOH)2L] (5) and [Zn(m-OCOPhOH)2L] (6), which were characterized by elemental analysis, 1H NMR, 13C NMR, IR, single crystal X-ray diffraction and fluorescence spectroscopies. In 1, the Zn atom is hexacoordinated, with a N3O3 coordination environment, whereas in the remaining structures the metal atom is envisaged as possessing distorted N3O2 irregular trigonal bipyramidal coordination geometries. All the compounds show interesting photo-luminescent properties in solid and solution states in DMF, DMSO and methanol, which are reported along with their TG-DTA thermal decomposition processes.