THE DIRECT L-TYPE RESONANCE-SPECTRUM OF (CF3CL)-CL-35 IN ITS VIBRATIONAL-STATE V(6)=1

Using the technique of Fourier transform microwave spectroscopy about 100 direct l-type resonance transitions for (CF3Cl)-Cl-35 in the first excited state of the doubly degenerate vibration nu(6) have been observed in the range of 2-18 GHz. These transitions are observable due to a mixing of states with Delta l = Delta k = +/-2 by the l-type (2,2) interaction. In addition to the (2,2) interaction it was necessary to include two further off-diagonal contributions to explain the spectrum: the (2,-4) interaction, which contributes to the splittings of the transitions with G = \k - l\ = 3, and either the (2,-1) or the (0,3) interaction corresponding to two different reductions of the effective Hamiltonian. The unitary equivalence of both sets of parameters has been demonstrated. The transitions show hyperfine splittings owing to quadrupole rotation-vibration interactions. In a simple approach the theory of Aliev and Hougen has been applied to explain the hyperfine structure patterns and to determine the (2, 2) quadrupole lk-type resonance parameter chi(6). Some features of direct I-type resonance spectra are discussed.