The spectra of the ZnC2H5 radical and its cation have been recorded by two
photoionization techniques, resonantly enhanced multiphoton ionization and
zero electron kinetic energy spectroscopy, respectively. The ionization pot
ential of the radical has been determined along with a number of vibrationa
l frequencies in the ground state of the cation and the excited state of th
e neutral. Based upon the spectroscopic data, models for the metal-carbon b
onding in metal alkyl radicals are proposed that predict relative bond stre
ngths for a number of species.