Synthesis, spectral, cyclic voltammetric studies, and single crystal X-ray structure determination of the planar NiS2P2, NiS2PN, and NiS2PC chromophores

Synthesis, spectral and cyclic voltammetric characterization of [Ni(dedtc)(4-MP)(2)](ClO4) (1), [Ni(dedtc)(4-MP)(NCS)](2), [Ni(dedtc)(PPh3)(NCS)] (3) and [Ni(dedtc)(PPh3)(CN)] (4) (dedtc = diethyldithiocarbamate, 4-MP = tri(4-iriethylphenyl)phosphine, PPh3 = triphenylphophine) are reported. IR spectra of complexes 1-4 show the characteristic thioureide (C-N) bands at higher wave numbers compared to that of the parent dithiocarbamate complex [Ni(dedtc)2]. The d-d transitions are observed in the region 452-482 nm. The CV studies clearly show the presence of reduced electron density oil the nickel ions in mixed ligand complexes 14 compared to the parent dithiocarbamate. Single crystal X-ray, structure studies show all the complexes to containplanar NiS2P2, NiS2PN, and NiS2PC chromophores in keeping with the observed diamagnetism. In all the complexes the Ni-S distances are asymmetric. The thioureide C-N distance of the complexes 1-4 are less than the C-N distance observed in the parent [Ni(dedtc)(2)].