SUBSTITUTED METAL-CARBONYLS .16. X-RAY PHOTOELECTRON SPECTROSCOPIC DIFFERENTIATION OF CHEMICALLY DISTINCT PHOSPHORUS ENVIRONMENTS IN UNIDENTATE COMPLEXES OF 1,1'-BIS(DIPHENYLPHOSPHINO)FERROCENE

X-Ray photoelectron spectra of M(CO)n(eta-1-dppf) (n = 5, M = Cr, 1, Mo, 2, W, 3; n = 4, M = Fe, 4), (OC)4Fe(mu-dppf)Mo(CO)5, 5, (OC)5M(mu-dppf)M(CO)5 (M = Cr, 6, Mo, 7, W, 8) and 1,1'-bis(diphenylphosphino)ferrocene (dppf), 9, suggested that the technique can be diagnostic for pendant and coordinated phosphines, and, in heterometallic cases, be used to differentiate phosphines bound to different metals. The resolution of the P(2p) bands permits a measurement of the relative binding energies for chemically distinct phosphorus sites in the same complex thus eliminating complications in calibration as well as sample charging problems normally associated with X-ray photoelectron spectroscopy in comparative studies.