Crystal and molecular structures of four bis(diphosphine) complexes of iron(II): bis[1,2-bis(diethylphosphino)ethane]di-iodoiron(II), dichloro-bis[o-phenylenebis(diphenylphosphine)]iron(II), bis(acetonitrile)bis-[o-phenylenebis(diphenylphosphine)]iron(II) di-iodide, and iodobis-[o-phenylenebis(diphenylphosphine)]iron(II) iodide

Abstract

The crystal structures of [Fel₂(depe)₂](depe = Et₂PCH₂CH₂PEt₂), [FeCl₂(opdp)₂]·thf, [Fe(MeCN)₂-(opdp)₂]I₂, and [Fel(opdp)₂]I·1.85CH₂Cl₂[opdp =o-phenylenebis(diphenylphosphine), thf = tetrahydrofuran] are discussed, and it is demonstrated that increasing steric pressures give rise to progressive change from low-spin octahedral co-ordination to high-spin octahedral co-ordination and then to five-co-ordination. The diphosphine ligand complexes are compared to complexes of other diphosphine ligands already in the literature.