INTRACAVITY LASER-ABSORPTION SPECTROSCOPY OF CHD3 FROM 10800 TO 18000CM(-1)

High resolution absorption spectroscopy of the CHD3 molecule has been completed by a systematic study between 10800 and 18000 cm-1. Due to t he very low intensity of the overtone bands in this energy range, the spectrum was recorded using the intracavity laser absorption spectrosc opy (ICLAS) technique. A new ICLAS spectrometer using a Ti:sapphire cr ystal as amplification medium has been developed to record the near in frared spectrum. Seven new bands have been rotationally resolved and a re reported for the first time. The vibrational analysis of the comple te set of data available up to now (36 bands) can be performed using a Dunham expansion or by taking into account explicitly the strong Ferm i resonance between the nu1(A1) CH stretching and the nu5(E) bending m ode. The CH stretching motion is also coupled with the CD stretching a nd the corresponding bands are well accounted by the standard local mo de model. Two other unexpected bands observed at 12235 and 14753 cm-1 have been assigned to combination bands involving the nu3(A1) mode.