O,O′-Dialkyldithiophosphato and O-alkyldithiophosphato nickel(II) complexes with bidentate P-donor ligands

The following complexes, having the general formula [Ni(S2P{O}OR)(P-P)] {R = Et (1), i-Pr (2), P-P = dppe; R = Et (3), PP = 1,4-bis(diphenylphosphino)butane (dppb)}, [Ni(S2P{OR}(2))(P-P)]X {R = i-Pr (4), Et (5), P-P = 1,2-bis(diphenylphosphino)ethane (dppe); R =. Et, P-P = 1,1-bis(diphenylphosphino)methane (dppm) (6); X = ClO4-} and [Ni(S2P{OR}(2))(dppe)X] {R = i-Pr, X = NCS- (7); R = Et, X = Br- (8)}, have been synthesized. All the compounds have been characterized by elemental analyses, IR, UV-Vis, and P-31{H} NMR spectral studies, magnetic and conductivity measurements. Single crystal X-ray analysis revealed the molecular structures of [Ni(S2P{O}OEt)(dppe)] (1), [Ni(S2P{O}OEt)(dppE)](EtOH)-Et-. (3) and [Ni(S2P{OEt}(2))(dppe)]ClO4 (5), and confirmed a square-planar geometry around the nickel atoms. We have reason to believe that the coordination geometry in [Ni(S2P{OEt}(2))(dppe)Br](H2O)-H-. (8) is probably tetrahedral with monodentate coordinated (S2P{OEt}(2)) monoanion. (C) 2003 Elsevier Science Ltd. All rights reserved.