New dithiocarbarnate and xanthate complexes of nickel(II) with iminophosphines

The synthesis of new cationic dithiocarbamate nickel(II) complexes with the mixed-donor bidentate ligands o-Ph2PC6H4-CH=NR is described. The derivatives of general formula [Ni(R-2'dtc)(o -Ph2PC6H4CH=NR)][ClO4][R' = Pr-i; R = Me (1), Et (2), Pr-i (3), Bu-t (4); R' = Bu-i; R = Me (5), Et (6), Pr-i (7), Bu-t (8)] have been obtained by direct reaction between Ni(ClO4)(2), the bis(dithiocarbamate) precursors [Ni(R-2'dtc)(2)] and the corresponding iminophosphine. Analogous reaction using [Ni(R'xan)(2)] as starting materials allowed the preparation of complexes [Ni(R'xan)(o-Ph2PC6H4CH=NR)][ClO4] [R' = Et; R = Me (9), Et (10), Pr-i (11), Bu-t (12); R' = Pr-i; R = Me (13), Et (14), Pr-i (15), Bu-t (16)]. The new complexes have been characterized by partial elemental analyses, conductivity measurements and spectroscopic methods (IR, H-1 and P-31{H-1} NMR). The X-ray structures of complexes (1), (5) and (13) are reported, revealing that the iminophosphine acts as chelating ligand with coordination around the nickel atom distorted from the square-planar geometry. (C) 2003 Elsevier B.V. All rights reserved.