Chelate structures of 5-(H/Br)-2-hydroxybenzaldehyde-4-allyl-thiosemicarbazones (H2L): Synthesis and structural characterizations of [Ni(L)(PPh3)] and [Ru(HL)(2)(PPh3)(2)]

Abstract

The reactions of 5-R-2-hydroxybenzaldehyde-4-allyl-thiosemicarbazone [R: H (L-1); Br (L-2)] with {M-II(PPh3)nCl(2)] (M = Ni, n = 2 and M = Ru, n = 3) in a 1:1 molar ratio have given stable solid complexes corresponding to the general formula [Ni(L)(PPh3)] and [Ru(HL)(2)(PPh3)(2)]. While the 1:1 nickel complexes are formed from an ONS donor set of the thiosemicarbazone and the P atom of triphenylphosphine in a square planar structure, the 1:2 ruthenium complexes consist of a couple from each of N. S and P donor atoms in a distorted octahedral geometry. These mixed-ligand complexes have been characterized by elemental analysis, IR, UV-Vis, APCI-MS, H-1 and P-31 NMR spectroscopies. The structures of [Ni(L-2)(PPh3)] (II) and [Ru((LH)-H-1)(2)(PPh3)(2)] (III) were determined by single crystal X-ray diffraction. (C) 2008 Elsevier Ltd. All rights reserved.