Optical Stark spectroscopy of the 206 (A)over-tilde1A - (X)over-tilde1A′ band of chloro-methylene, HCCl

The laser induced fluorescence spectra of the 2(0)(6)(A) over tilde (1)A '' - (X) over tilde (1)A' band of a rotationally cold (< 20 K) molecular beam sample of chloro-methylene, HCCl, has been recorded, field-free and in the presence of a static electric field. The field-free spectrum has been analyzed to produce an improved set of spectroscopic parameters for the (A) over tilde (1)A '' (060) vibronic state. The magnitude of the a-component of the permanent electric dipole moment, mu(a), for the (X) over tilde (1)A' (000) vibronic state has been determined to be 0.501(1) D from the analysis of the observed electric field induced shifts. Comparisons with theoretical predictions and flouro-methylene, HCF, are presented. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694245]