Synthesis, spectral and structural studies of zinc(II) complexes of salicylaldehyde N(4)-phenylthiosemicarbazone

Five Zn(II) complexes of salicylaidehyde N(4)-phenylthiosemicarbazone (H2L) have been synthesized and physicochemically characterized. Out of the five Zn(II) complexes, one is binuclear {[(ZnL)(2)]center dot 3C(2)H(5)OH (1)} and the other four are mononuclear {[Zn(HL)(2)]center dot C2H5OH (2), [ZnLbipy]center dot 1/2H(2)O (3), [ZnLphen]center dot H2O (4) and [ZnLdmbipy] (5)} in nature. In complex 2, IR band due to v(Zn-O) is absent and also the -OH signal due to the phenolic -OH group appears at delta = 11.38 ppm obtained from the H-1 NMR spectrum supports the existence of free -OH group. Complexes 3-5 are heterocyclic base adducts and their IR spectra display bands characteristic of coordinated heterocyclic bases. The molecular structure of one of the complex 3 is resolved by single crystal X-ray diffraction studies. The complex 3 is orthorhombic with a space group P2(1)cn. The Zn(II) in 3 is five coordinated and is having an approximately trigonal bipyramidal geometry with distortion from square based pyramid (TBDSBP). (c) 2007 Elsevier B.V. All rights reserved.