HIGH-RESOLUTION LASER SPECTROSCOPY OF THE C(TIDLE)2-DELTA-X(TIDLE)2-SIGMA+ TRANSITION OF CAOH AND CAOD - VIBRONIC COUPLING AND THE RENNER-TELLER EFFECT

The C (2)DELTA-X (2)SIGMA+ transition of CaOH and CaOD has been observed in the blue region of the spectrum. This electronically forbidden transition becomes allowed through vibronic coupling with the bending mode. The (010)-(000) band for CaOH and the (010)-(000), (020)-(010), (010)-(010), (000)-(010), and (010)-(02(0)0) bands for CaOD have been recorded and analyzed at high resolution. The C (2)DELTA(000) state of CaOD has a band origin at 21 907.128(1) cm-1, a rotational constant B of 0.293 536(7) cm-1, and a spin-orbit constant A of 11.4944(5) cm-1. A rotational analysis of the C (2)DELTA(020)-mu-SIGMA and the C (2)DELTA(020)kappa-SIGMA states of CaOD has also led to the first experimental determination of the Renner-Teller parameter g4 for a (2)DELTA state at g4 = -0.038 62(9) cm-1.