Rovibrational and rotational spectroscopy of the ν2=1, ν5=1, and ν3=2 levels of 13CH337Cl

Fourier-transform infrared (IR) spectra between 1235 and 1680 cm(-1) and millimeter wave spectra between 198 and 455 GHz of monoisotopic (CH337)-C-13 Cl have been recorded and analysed simultaneously, taking into account all Coriolis, alpha-resonance, and l-type interactions in the polyad of the nu(2)=1, nu(5)=1 and nu(3)=2 levels. Several alpha-resonances (Deltak=+/-2, Deltal=-/+1) generating perturbation-all owed transitions have been assigned both in the rovibrational and rotational spectra. I This enabled us to determine accurately and independently A(0)=5.2057128 (72) cm(-1), D-K(0)=8.3968 (105)x10(-5) cm(-1), and even H-K(0)=3.95 (38) x 10(-9) cm(-1). With 52 upper state parameters varied, more than 5300 IR wavenumbers and 162 rotational frequencies pertaining to the excited vibrational states were fitted within their experimental accuracy. The textbook example of a first-order Coriolis resonant crossing between the A and E fundamental vibrational levels (nu(2)=1 and nu(5)=1) is discussed in detail with implications for the structures of the corresponding parallel nu(2) and perpendicular nu(5) bands and their intensity perturbations.