The two highly flexible ligands 1,1′-bis(4-phospholanobutyl)ferrocene (5a) and 1,1′-bis(5-phospholanopentyl)ferrocene (5b) reacted with [PtCl2(cod)] (cod = 1,5-cyclooctadiene), [AuCl(tht)] (tht = tetrahydrothiophene) and [{RhCl(CO)2}2] to give the respective chelate complexes cis-[PtCl2(5a,b-κ2P,P′)] (7a,b), [AuCl(5a,b-κ2P,P′)] (8a,b) and trans-[RhCl(CO)(5b-κ2P,P′)] (9b). Treatment of 5a,b with selenium gave the corresponding selenides 6a,b. All compounds have been fully characterised by NMR (1H, 13C, 31P) and IR spectroscopy and mass spectrometry. In addition, crystal structures of 6a, 7b, 8a,b and 9b were determined by X-ray crystallography. Furthermore, the rhodium-catalysed hydroformylation of 1-octene has been studied with ligand 5b.
