FOURIER-TRANSFORM INFRARED AND TUNABLE DIODE-LASER SPECTER OF THE (CCH6)-C-13-C-12 NU(12) TORSION-VIBRATIAN-ROTATION BAND - FREQUENCIES, INTENSITIES, AND BARRIERS TO INTERNAL-ROTATION

High resolution spectra in the 12,2 mu m region of the upsilon(12) fun damental of the minor isotopomer (CCH6)-C-13-C-12 have been recorded. Torsional coriolis interaction of the excited upsilon(12)=1 state with the close lying excited torsional upsilon(6)=3 State leads to observe d splittings of up to several tenths of cm(-1) in upsilon(12) near the crossing region at K Delta K=-18. Torsional splittings measured with a high resolution tunable diode spectrometer (TDL) and more than 2200 lines measured with a Fourier transform spectrometer (FTS) have been a nalyzed in a global nonlinear least squares fit to a symmetric top Ham iltonian. The standard deviation of the overall fit is 5.5X10(-4) cm(- 1). From 17 intensity measurements of individual lines, a square dipol e moment of R(upsilon)(2)=7.45(29)X10(-4) D-2 has been derived for the upsilon(12) fundamental.