81097-98-5Relevant academic research and scientific papers
Cobalt(II) and Nickel(II) Trithiocarbonate Complexes as Nucleophilic Reagents. Reactivity and X-Ray Structure of the Trithiocarbonate Complex *1.5thf
Bianchini, Claudio,Mealli, Carlo,Meli, Andrea,Scapacci, Gian Carlo
, p. 799 - 804 (1982)
The trithiocarbonate complexes and are highly activated toward electrophilic reagents.The unco-ordinated sulphur atom is found to displace the halide ion from alkyl halides or weakly bound ligands from other organometallic derivatives to give sulphur alkylated cations or CS3-bridged binuclear complexes respectively.The crystal and molecular structure of the trithiocarbonate complex *1.5 thf has been determined by standard X-ray methods.The compound is monoclinic, space group C2/c, Z=8, a=42.420(7), b=10.221(4), c=35.449(7) Angstroem, β=124.93(8) deg.The complex cation is five-co-ordinated by the three phosphorus of the tppme ligand and two sulphur atoms of the trithiocarbonate anion.The latter group can be considered planar, the methyl carbon atom almost lying in the CS3 plane.The bonding between the Co(tppme) and S2CS fragments is analysed in terms of qualitative molecular orbital arguments.This trithiocarbonate complex udergoes lidand nucleophilic substitution with diethylamine to form the dithiocarbamate complex *0.5CH2Cl2.
Spectroelectrochemistry of nickel complexes. Voltammetric and ESR studies of the redox reactions of phosphine-dithiolate and phosphine-catecholate complexes of nickel
Bowmaker,Boyd,Campbell
, p. 2403 - 2412 (2008/10/08)
The redox properties of nickel(II) complexes of the type [Ni(PPh3)2L]n+ (L = dithiolate (n = 0) or dithiocarbamate (n = 1)) and Ni(dpe)L (dpe = bis(diphenylphosphino)ethane, L = dithiolate or catecholate) have been studied by cyclic voltammetry at a platinum electrode, and the products of the redox reactions have been identified by electron spin resonance spectroscopy. All of these complexes show reversible or quasi-reversible one-electron reduction processes, and the reduction potentials for the PPh3 complexes are about 0.5 V higher than those of the corresponding dpe complexes. In the case of triphenylphosphine complexes such as Ni(PPh3)2((CN)2C2S2), the voltammetry shows evidence of a dissociation equilibrium involving loss of triphenylphosphine from the nickel species present after the electron-transfer process. The frozen-solution ESR spectra of the reduction products show large, anisotropic hyperfine coupling to two equivalent 31P nuclei and anisotropic g values characteristic of d9 nickel(I) species. The PPh3 complexes have smaller 31P hyperfine coupling constants than the corresponding dpe complexes. The 31P hyperfine coupling parameters have been analyzed for some representative complexes, and the amount of spin density transferred from the metal to the phosphine ligands has been estimated. In addition to the reduction process, the catecholate complexes undergo a reversible one-electron oxidation. The ESR spectra of the products of such oxidations show only a small 31P hyperfine coupling, hyperfine coupling to nuclei in the catecholate ligand, and almost isotropic g values. These species are therefore formulated as nickel(II) complexes containing coordinated semiquinone radical anions.
