Production ofPb+ions following 5dcore photoionization of tetramethyl lead as revealed by a coincidence experiment

Ionic fragmentation following Pb 5d core-level ionization in tetramethyl lead (${\mathrm{PbMe}}_4$) has been studied with synchrotron radiation. In the wavelength range between 45 and 75 nm, photoionization of the Pb 5d core levels is observed in the threshold electron spectrum of ${\mathrm{PbMe}}_4$. The efficiency for the production of ${\mathrm{Pb}}^{+}$ ions increases dramatically in this region, while those of other fragment ions decrease. It is shown that the ${\mathrm{Pb}}^{+}$ ion is predominantly produced following 5d photoionization, by use of the threshold electron—photoion coincidence technique.