Redox Processes in the Systems Containing Square-planar Nickel(II) Bis(chelate) Compounds

Electronic spectroscopy was used to study the reaction of tetra-n-butylammonium bis(1-mercapto-2-hydroxynaphthyl)nickelate(II) {[n-Bu(4)N][Ni(Mhn)(2)]} with bis(dithiobenzyl)nickel [Ni(Dtb)(2)] in acetone, acetonitrile, dimethylformamide, methylene chloride, and chloroform solutions. The resulting complex spectrally differs from the initial compounds. It is established that the redox reaction between the initial nickel complexes proceeds only in polar solvents and in the presence of water. The spectroscopic data provide evidence that [Bu(4)N][Ni(Mhn)(2)] oxidizes in this reaction, while Ni(Dtb)(2) is reduced to form [Bu(4)N][Ni(Dtb)(2)] salt.