A mixed valence µ-oxo iron(III)–iron(II) complex: a polynuclear iron–sodium–oxo aggregate from the chemical reduction of a µ-oxo di-iron(III) complex

Abstract

Reduction of {[Fe(acacen)]₂O}{acacen =[MeC(O^–)CHCMeNCH₂]₂}[Fe–O, 1.77(1)Å Fe–O–Fe, 150.7(13)°] with sodium metal to give an iron–sodium–oxo aggregate {[Fe(acacen)]₂ONa}₂, containing the monoanionic µ-oxo iron(II)–iron(III) moiety, [Fe–O–Fe]^– occurs with a significant lengthening of the Fe–O bonds, and contraction of the Fe–O–Fe angle [Fe–O, 1.999(6) and 2.069(6)Å Fe–O–Fe, 134.9(4)°], as shown by a crystal structure determination.