THE SPECTROSCOPY OF THE CDCH3 RADICAL AND ITS POSITIVE-ION

Resonantly enhanced multiphoton ionization, REMPI (2 color, 1+1'), and zero electron kinetic energy-pulsed field ionization, ZEKE-PFI, spect ra are reported for the first organometallic radical, CdCH3. The combi ned REMPI and ZEKE-PFI data have necessitated a change of assignment f or one of the bands of the (A) over tilde(2)E<--(X) over tilde(2)A(1) ?A, electronic transition of the neutral radical. The new assignment a nd the revised molecular parameters are reported. The ZEKE-PFI spectru m yields the adiabatic ionization potential for the CdCH3 radical and four of the six possible vibrational frequencies of its cation. Clearl y resolved rotational (K level) structure is observed in some bands of the ZEKE-PFI spectrum, providing a unique experimental test for newly extended ZEKE-PFI rotational selection rules. (C) 1998 American Insti tute of Physics. [S0021-9606(98)00604-7].