Optisch aktive Uebergangsmetall-Komplexe. CV. Faciale und meridionale Chromcarbonylphosphin-Komplexe

Article abstract of DOI:10.1016/0022-328X(93)86065-P

The optically active, facial complex Cr(CO)3(PP'P'') (1) with the tridentate ligand PP'P''=(R)-(+)-1,2,4-tris(diphenylphosphino)butane has been synthesized and characterized.The complex Cr(CO)3(PP')P'' (PP'=(R)-(+)-prophos, P''=PMe2Ph) forms two pairs of diastereomers, facial (3, 4) and meridional (5, 6), respectively, that can be separated by preparative column chromatography.Surprisingly, the CD spectra of Cr(CO)3(PP'P'') (1) and the facial distereomer of Cr(CO)3(PP')P'' (3), which have the same configuration at the Cr atom, are dissimilar.The meridional configuration of the two isomers 5 and 6 of Cr(CO)3(PP')PMe2Ph is supported by the 31P and 1H NMR spectra of the optically inactive complex Cr(CO)3(PP')P'' (PP'=1--2-(diphenylphosphino)ethane P''=PMePh2), which forms the meridional isomers 9 and 10.