DISPERSED FLUORESCENCE SPECTROSCOPY AND TRANSITION DIPOLE-MOMENT OF HCO (B)OVER-TILDE (2)A'-(X)OVER-TILDE (2)A'

Dispersed fluorescence spectra of (B) over tilde(2)A'-(X) over tilde(2 )A' transitions are measured on exciting HCO to the vibrational levels (0,0,0), (0,0,1), (0,1,0) and (1,0,0) of B (2)A' in a gas cell. Vibra tional energies of bound and resonant states are determined for energy up to 17 500 cm(-1) from the ground vibrational level of the X(2)A' s tate. Rotationally resolved spectra of the bands (B) over tilde(2)A'-( X) over tilde(2)A' 2(3)(0)3(1)(0), 2(4)(1) and 2(2)(0)3(2)(1) were rec orded and analyzed. Abnormal intensities in the P, Q and R branches ar e due to the mechanism of ''axis switching''. From the ratios of emiss ion intensity of a- and b-type transitions, without taking into accoun t the varied lifetimes of rotational states of the upper electronic st ate, the directions of transition dipole moments of these bands are de termined to be 39 - 43 degrees to the inertial a axis.