New members of the {Fe(NO)2}10 dinitrosyliron complexes bound with [thiolate, thiolate] and [amide, amide] ligations

Abstract

The first dianionic {Fe(NO)(2)}(10) dinitrosyliron complexes (DNICs) [Fe(SC(7)H(4)SN)(2)(NO)(2)](2-) (1) and [Fe(OC(7)H(4)SN)(2)(NO)(2)](2-) (2), coordinated with thiolates and amides, were prepared by the reaction of Fe(TMEDA)(NO)(2) with 2 equiv of ligands [SC(7)H(4)SN](-) and [OC(7)H(4)SN](-), respectively. The reversible interconversion between the dianionic {Fe(NO)(2)}(10) DNICs 1/2 and the anionic {Fe(NO)(2)}(9)[Fe(SC(7)H(4)SN)(2)(NO)(2)](-) (3)/[Fe(OC(7)H(4)SN)(2)(NO)(2)](-) (4), respectively, was demonstrated. The transformation of DNICs 2 and 3 into the thermally stable DNICs 1 and 4, respectively, via the ligand-exchange reaction reveals that [OC(7)H(4)SN](-) shows a high binding affinity toward the {Fe(NO)(2)}(9) motif and [SC(7)H(4)SN](-) prefers the {Fe(NO)(2)}(10) motif. This result rationalizes that the intermolecular electron transfer from DNIC 2 to DNIC 3 occurs to lead to the formation of the more thermally stable DNICs 1 and 4 upon the reaction of DNICs 2 and 3 in tetrahydrofuran.