DIODE-LASER SPECTRUM AND ROVIBRATIONAL ANALYSIS OF THE NU-2+NU-5 BAND OF CF3CL

The vibration-rotation spectrum of the ν2 + ν5 band of CF3Cl, with natural isotopic abundance, has been investigated in the range 1332-1360 cm-1 with a resolution of about 0.002 cm-1 using a tunable diode laser spectrometer. The measurements have been performed by keeping the sample at low temperature ({reversed tilde equals}240 K) to reduce the interferences arising from hot bands. Both J and K structures have been resolved and analyzed in the P,R(P, Q, R) subbranches, and many individual transitions covering the ranges -28 ≤ KΔK ≤ 24 up to J = 68, and -18 ≤ KΔK ≤ 24 up to J = 58, have been identified for CF335Cl and CF337Cl, respectively. The perturbation effect due to the Δ1 = Δk = ±2 resonance has been found significant even in other transitions with low K values and not only for the kl = 1 level. Excited state parameters up to the quartic terms have been determined for the ν2 + ν5 band of both isotopic varieties from a fit of 1140 (35Cl) and 187 (37Cl) lines with standard deviations of 5.8 and 6.7 × 10-4 cm-1, respectively. © 1992.