High resolution photoelectron studies: Electric field gradient splittings of Cd and Sn 4d energy levels in organometallic compounds

High resolution photoelectron spectra of Me2Cd (Me = CH3) in the gas phase, and organotin compounds in the solid state show that the 4d9 final state produced in the photoelectron experiment splits in the presence of ligand fields. Only the C20 crystal field term (the term that transforms like the electric field gradient) contributes to the splitting. The 4d 3 2 splitting in Me2Cd and trans-Me2Sn(BzBz)2 (BzBz = anion of dibenzoylmethane) are 0.21 ± 0.01 eV and 0.35 ± 0.1 eV respectively. The observed 4d 5 2 linewidth for Ph4Sn (Ph = C6H5) of 0.67 eV indicates that very narrow linewidths can be obtained on molecular nonconducting solids. The constant spin-orbit splitting values, combined with nuclear field gradients from Mössbauer and NQR measurements, strongly indicate that a previously proposed explanation for the increase in apparent spin-orbit coupling in Cd metal is untenable. © 1976.