Metal–ligand cooperativity across two sites of a square planar iron(ii) complex ligated by a tetradentate PNNP ligand

Abstract

An iron(II) complex with a square planar geometry and S = 1 ground state was synthesized using a rigid tetradentate bisphosphine-bisamide [PNNP]²⁻ ligand. This complex was shown to bind an equivalent of PMe₃ to produce a five-coordinate low spin complex, and to react with two equivalents of borane reagents via addition of two B–H bonds across the metal–amide bonds in a metal–ligand cooperative fashion.