Syntheses and structural studies on some new dithiophosphinato complexes of nickel(II), cobalt(II) and mixed pyridino complexes thereof

Abstract

Four different, alkyl(4-methoxyphenyl)dithiophosphinic acid metal complexes, namely, trans-bis-[iso-propyl (4-methoxyphenyl)dithiophosphinato]nickel(II), 1; bis-{[iso-propyl (4-methoxyphenyl)-dithiophosphinato]}cobalt(II), 2; bis-{[sec-butyl (4-methoxyphenyl)-dithiophosphinato]}cobalt(II), 3 and bis-{[iso-amyl (4-methoxyphenyl)-dithiophosphinato]}cobalt(II), 4 were prepared. As 1 and 2 were synthesized for the first time, their structures were also elucidated. Starting with these four-coordinated complexes, novel, mixed (pyridino) dithiophosphinic acid complexes of Ni(II) and Co(II) were also prepared. These complexes were characterized by elemental analysis and NMR (1H-, 13C-, 31P-); MS; FTIR; and Raman spectroscopies. TGA and DTA data were also made use of to support the structures revealed by spectroscopy. The magnetic susceptibilities of the complexes were measured to confirm the hybridization patterns and the geometries. The crystal structures of the cobalt pyridino-DTPA complexes were analyzed. X-ray analyses show that the P–S bonds in the complexes are essentially of the same order; that is, electron delocalization prevails.