Transient vibrational spectroscopy by flash photolysis stimulated emission pumping: 3 nu 2 of singlet methylene
Abstract
A vibration-rotation spectroscopic method based on stimulated emission pumping has been developed for transient molecules generated by flash photolysis. This method may be generally applicable to radicals with electronic excited states accessible by visible or UV laser pulses. This first demonstration on the bending v2 =3 level of ã 1A1 CH2 generated a vibrational term value of 3950.45(7) cm-1 and the rotational constants A=25.665(40), B=11.470(7), and C=6.7140(61) cm-1. These constants indicate that the 3ν2 level is well below the bending-potential barrier. Perturbations of several rotational levels by the triplet state are identified. In addition, and most interestingly, abnormally intense ΔKa =3 transitions were observed in the ã←b∼ 2163 band.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- December 1988
- DOI:
- 10.1063/1.455331
- Bibcode:
- 1988JChPh..89.7033X
- Keywords:
-
- Laser Pumping;
- Methylene;
- Photolysis;
- Stimulated Emission;
- Vibrational Spectra;
- Fine Structure;
- Flash Lamps;
- Free Radicals;
- Molecular Energy Levels;
- Molecular Rotation;
- Atomic and Molecular Physics