Nickel(II) Complexes of ONS and ONN Chelating Thiosemicarbazones With Triphenylphosphine Co-Ligands

Abstract

Reactions of 5-bromo-2-hydroxy-benzaldehyde-S-R-4-R1- thiosemicarbazones, [R, R1 = H,H (L1); CH<inf>3</inf>, H (L2); H, C<inf>6</inf>H<inf>5</inf> (L3); CH<inf>3</inf>, C<inf>6</inf>H<inf>5</inf> (L4)] with [Ni(PPh<inf>3</inf>) <inf>2</inf>Cl<inf>2</inf>] in 1:1 molar ratio yielded complexes of general formula [Ni(L)(PPh<inf>3</inf>)]. While the complexes of L1 and L3 involve the ONS donor set of the thiosemicarbazone, the L 2 complexes utilize the ONN set. The reaction of L4 and the nickel salt gave the L3 complex by loss of the CH<inf>3</inf> group from the sulphur. The complexes were characterized by physico-chemical and spectroscopic methods. The structures of the L1 and L2 complexes have been determined by single crystal X-ray diffraction and a new coordination mode (ONN) of salicylaldehyde thiosemicarbazones has been identified. © 2009 Springer Science+Business Media B.V.