Journal of Chemical Physics, Vol.105, No.19, 8515-8522, 1996
The Infrared-Spectroscopy and Dynamics of Oco-HCl and Sco-HCl - An Example of Mode-Specific Intermolecular Energy-Transfer
Optothermal near infrared laser spectroscopy has been used to study the OCO-HCl and SCO-HCl complexes by exciting the H-Cl stretch using an F-center laser. In both cases, the two isotopic forms associated with (HCl)-Cl-35 and (HCl)-Cl-37 have been observed. All of the observed spectra are consistent with and analyzed in terms of a linear structure. Vibrational predissociation is observed to be abnormally fast in the OCO-HCl complex, considering the rather weak coupling between the intermolecular degrees of freedom and the H-Cl stretch suggested by the small vibrational frequency shift associated with complex formation. Comparisons are made between the two systems studied here that indicate that this anomalous rate is due to a near resonance between the energy available to the fragments after the photodissociation of the complex and the asymmetric stretch of the CO2 fragment.
Keywords:LASER-ABSORPTION-SPECTROSCOPY;TO-STATE PHOTODISSOCIATION;VIBRATIONAL PREDISSOCIATION;HIGH-RESOLUTION;VANDERWAALS MOLECULES;HF COMPLEXES;DIMER;SPECTRA;DISTRIBUTIONS;STRETCH