A pulsed field ionization study of the dissociative photoionization reaction CD4+hν→CD3 ++D+e−

We have examined the titled dissociation reaction near its 0 K threshold using the pulsed field ionization-photoelectron (PFI-PE) and PFI-PE-photoion coincidence methods. This study yields a value of 14.4184±0.0010 eV for the 0 K threshold. The PFI-PE spectrum for CD4 exhibits a sharp step at the 0 K threshold, indicating that the dissociation of excited CD4 in high-n (n⩾100) Rydberg states at energies above the dissociation threshold occurs in ⩽10−7 s. The energetic data for CD3/CD3 + and CD4/CD4 + are found to be in excellent agreement with those for CH3/CH3 + and CH4/CH4 + after taking into account the zero-point-vibrational-energy corrections.