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

• Dithiophosphinic acid complexes were synthesized.
• Spectroscopic characterizations of the complexes were done.
• TGA/DTA of complexes were carried out.
• X-ray analyses of cobalt-pyridino complexes were performed.

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.

Four different, four-coordinated alkyl(4-methoxyphenyl)dithiophosphinic acid metal complexes were prepared. As trans-bis-[iso-propyl (4-methoxyphenyl)dithiophosphinato]nickel(II), 1 and bis-{[iso-propyl (4-methoxyphenyl)-dithiophosphinato]}cobalt(II), 2 were synthesized for the first time, these compounds were also characterized spectroscopically. Starting with these four-coordinated complexes, novel, mixed (pyridino) DTPA complexes of Ni(II) and Co(II) cations were prepared (5, 6, 7, 8 and 9). The crystal structures of the four cobalt pyridino-DTPA complexes (5, 7, 8 and 9) were analyzed.Figure optionsDownload as PowerPoint slide