Rotational Raman excitation profiles of symmetric tops: Subpicosecond rotation dependent lifetimes in the à state of ammonia
- 15 February 1987
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 86 (4), 1703-1714
- https://doi.org/10.1063/1.452169
Abstract
The analysis of Raman excitation profiles of rotational scattering transitions is shown to be a sensitive measure of rotationally specific intramolecular dynamics in the subpicosecond time regime. O, P, Q, R, and S Raman REPs of ammonia are reported and theoretically treated using previously derived resonance rotational scattering intensity expressions. Resonance rovibrational Raman spectra are obtained with UV Raman excitation continuously resonant with the v’2 =2 vibronic band (207–210 nm) of the NH3 X̃ → à absorption spectrum. The resulting REP analysis reveals that the rates of photodissociation on the à state surface have a significant rotational quantum dependence in the 22 band. Rovibronic lifetimes decrease from 140 to 70 fs as J increases from 2 to 8 in this resonant à state vibrational level. These lifetime effects are largely ascribed to centrifugal effects.Keywords
This publication has 24 references indexed in Scilit:
- Vibronic origin of 1141 and the Coriolis effect on the excited-state lifetimes of the rotational levels of 51 in ~A 1A2 formaldehydeThe Journal of Physical Chemistry, 1986
- Ion dip spectroscopy as a means of probing fast predissociating species: NH3 Ã1A''2 stateChemical Physics Letters, 1986
- Predissociation dynamics of Ã-state ammonia probed by two-photon excitation spectroscopyChemical Physics, 1985
- The direct ultraviolet absorption spectrum of the A'~A2" .rarw. ~X'A1 transition of jet-cooled ammoniaThe Journal of Physical Chemistry, 1984
- Homogeneous linewidths of single rotational lines in the ‘‘channel three’’ region of C6H6The Journal of Chemical Physics, 1984
- Coriolis interactions and intramolecular vibrational redistribution in jet-cooled pyrimidineChemical Physics Letters, 1983
- Resonance Raman Scattering: The Multimode Problem and Transform MethodsAnnual Review of Physical Chemistry, 1982
- Dynamics of the unimolecular dissociation of hydroperoxo. Phase space coupling, microcanonical rate coefficients, and rotational effectsThe Journal of Physical Chemistry, 1982
- A study of the rotational state dependence of predissociation of a polyatomic molecule: The case of ClO2The Journal of Chemical Physics, 1981
- The 2491 Å band system of NO2. Rotational structure and evidence for predissociation in the zero-point levelCanadian Journal of Physics, 1976