Abstract
The high resolution technique of Stark quantum beat spectroscopy is used to examine the electric dipole moment function for the first excited singlet state (à 1A2) of formaldehyde-h2 and formaldehyde-d2. The high precision of these measurements (i.e., better than 5 parts in 104) enables detailed determination of a-axis dipole moment components (μa) for individual J = 2 rovibronic levels in the ν4 out-of-plane bending mode. In the case of 2 1,1 rotational levels, we find μa (40) = 1.4784(7) D and μa (41) = 1.4678(4) D for H 2CO. For D2CO the measured 21,1 dipole moments are μa (40) = 1.4698(6) D,μa(4 1) = 1.4693(3) D, and μae(43) = 1.4786(7) D. The state-specific variations in μa revealed by this study reflect the structural influences exerted by the pervasive S1∼ S0 nonadiabatic interactions and the pyramidally distorted equilibrium configuration which characterize the à state of formaldehyde. The origin and experimental manifestation of the out-of-plane dipole moment component (μc) in nonrigid à 1A2 formaldehyde is also discussed.
Original language | English (US) |
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Pages (from-to) | 4150-4167 |
Number of pages | 18 |
Journal | The Journal of chemical physics |
Volume | 90 |
Issue number | 8 |
DOIs | |
State | Published - 1989 |
Externally published | Yes |
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry