Half-sandwich complexes of ruthenium, rhodium and iridium with a chiral bisphosphine monoselenide

Monoselenation of the chiral bisphosphine (S)-(+)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyldi-t-butylphosphine gives the first enantiomerically pure chiral bisphosphine monoselenide prepared from a commercially available chiral bisphosphine. This bisphosphine monoselenide ligand is an effective chelating ligand that utilizes a [P,Se] donor set when forming chelates with half-sandwich complexes of ruthenium(II), rhodium(III) and iridium(III). These complexes have been characterised spectroscopically and, in some cases, crystallographically. The chirality of the ligand influences and controls the metal-centred chirality yielding one of two possible chelate complexes with high diastereoselectivity.