ESR/DFT study of bis-iminophosphorane cation radicals.

Bis-iminophosphoranes containing various types of linkers between two R3P==N moieties were electrochemically oxidized at controlled potential in situ in the electron spin resonance (ESR) cavity. For linkers constituted of phenylenes, conjugated phenylenes or merely a dicyanoethylenic bond, this oxidation led to well-resolved ESR spectra which were characterized by their g values and by their 1H, 14N and 31P isotropic hyperfine constants. These coupling constants agree with those calculated by DFT for the corresponding cation radicals.

Highly efficient P-N nickel(II) complexes for the dimerisation of ethylene.

New P-N ligands featuring a phosphino group and an iminophosphorane moiety were successfully employed in the nickel-catalysed dimerisation of ethylene.