THE HIGH-FREQUENCY ROTATIONAL SPECTRUM OF 1,1,1-TRICHLOROETHANE AND THE OBSERVATION OF K=3 SPLITTING

Measurements of the rotational spectrum of 1,1,1-trichloroethane, CH3C Cl3, were made up to 678 GHz, J '' = 143, and K = 75, and accurate val ues for sextic-level spectroscopic constants were determined. Lamb-dip millimeter-wave spectra and sideband FIR-laser spectra were used to o bserve the K = 3 splitting characterized by the splitting constant h(3 ) = 1.54(15) X 10(-11) MHz. The present determination and several othe r recent determinations of h(3) for axially substituted pyramidal mole cules allow further empirical rules to be derived regarding the magnit ude of h(3) splitting constants in symmetric top molecules. (C) 1995 A cademic Press, Inc.