ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
High resolution Stark quantum beat spectroscopy is demonstrated to be a powerful method to determine magnitude and orientation of excited state dipole moments in asymmetric polyatomic molecules. We measured the dipole moments μ of the vibrationless S1 state of planar propynal and αD-propynal in a pulsed supersonic jet and determined both components of the μ vector in the molecular plane: μ'a=0.874(10)D, μb=1.06(2)D, ||μ'||=1.374(22) D for HC≡CCHO; μ'a=0.863(10)D, μb=1.04(1) D ||μ'||=1.351(14) D for HC≡CCDO. The results are related with recently reported microwave data of the ground state dipole moment μ(S0) and are interpreted in terms of electron delocalization from the carbonyl group to the ethinyl moiety. The dipole moments of S0 and S1 propynal are oriented essentially along the CO bond. The applicability of the Stark quantum beat technique to polyatomic molecules is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.454198
