HIGH-RESOLUTION GAS-PHASE CORE-LEVEL X-RAY PHOTOELECTRON-SPECTROSCOPY OF PH3 AND H2S WITH A SYNCHROTRON SOURCE - OBSERVATIONS OF VIBRATIONAL STRUCTURE ON RESOLVED SPIN ORBIT CORE (2P) LINES

High-resolution core-level photoelectron spectroscopy of PH3 and H2S gave well-resolved spin-orbit components (DELTA(s.o.) PH3 860 meV, H2S, 1210 meV). The nu' = 1 vibrational components of PH3 were clearly discernable (299 meV, 2411 cm-1). The vibrationally excited component on the core (2p) photoelectron lines of PH3 is weaker than that for SiH4. For PH3 the nu' = 1 band is 19% of the nu' = 0 fundamental in the 2p photoelectron spectrum. For H2S the vibrational component was so weak it could not be reliably extracted. An approximate spectral moment analysis of PH3 indicated a bond shortening of 0.08 angstrom (versus an estimate of 0.17 angstrom shortening for SiH4, which showed a much stronger vibrationally excited profile, by the same method). The lesser bond shortening on core ionization accounts for the reduced vibrational excitation in the spectrum of PH3.