Transition-metal dithiolene complexes. Part XIII. Nitric oxide adducts of iron bis(diaryl-1,2-dithiolenes)

Abstract

A series of mononitrosyl iron bis(diaryl-1-2-dithiolene)-complexes, [Fe(NO)(S₂C₂Ar₂)₂]⁰[Ar = 4-Me·C₆H₄, 2-, 3-, or 4-MeO·C₆H₄, 3,4-CH₂O₂C₆H₃or 2,5-(MeO)₂C₆H₃] have been prepared. The voltammetry and polarography of these complexes has been investigated, and it is shown that the compounds are part of a four-, and possibly five membered electron transfer series, [Fe(NO)(S₂C₂Ar₂)₂]^z[z=–2, –1,0, +1, (or + 2)]. The values of the half-wave potentials for the couple [Fe(NO)(S₂C₂Ar₂)₂]^z e^–⇌[Fe(No)(S₂C₂Ar)₂]^{z – 1} depend on the substituents, Ar, but the latter have very little effect on the nitrosyl group stretching frequency. The e.s.r. and electronic spectra of the complexes are reported.