Diode Laser Jet Spectra and Analysis of the ν3 and ν8 Fundamentals of CHF2Cl

Abstract

High-resolution infrared spectra have been measured for mixtures of CHF 2 Cl in Ne, expanded in a supersonic planar jet. We present the analysis for the ν 3 and ν 8 fundamentals of CHF 2 35 Cl and CHF 2 37 Cl. C 2001 Academic Press

Torsional splittings in the diode laser slit-jet spectra of the ν6 fundamental of 1-chloro-1,1-difluoroethane (HCFC-142b)

“…The effect of asymmetry favors the formation of Wangtype eigenfunctions, consisting of combinations (sum over K q ) of basis functions shown in Eq. (9). All basis functions occurring in a given Wang-type eigenfunction have the same parity in K a and the same parity in K c , with K a = K q for a near prolate symmetric top, therefore the parities of K a and K c are defined in these eigenfunctions as well.…”

“…The presence of hot-bands and different chlorine isotopic species renders the analysis even more troublesome. We have previously demonstrated [6][7][8][9][10] that the diode laser slit-jet technique, which combines high resolution (0.001 cm À1 typically) with low rotational and vibrational temperatures, can simplify the spectra enormously, allowing for unambiguous assignments and successful analyses.…”

New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22)

“…Both isotopologues are asymmetric tops belonging to the C s point group, and each possess a single plane of symmetry (CHCl) containing the a and c principal axes. Chlorodifluoromethane has nine fundamental vibrational modes; six (ν 1 -ν 6 ) are symmetric (A ) with respect to the symmetry plane, appearing as a/c-type bands in the IR, and three (ν 7 -ν 9 ) are antisymmetric (A ) with respect to the symmetry plane, corresponding to b-type bands (Snels and D'Amico, 2001). The 730-1380 cm −1 spectral range covered in the present work contains a number of strong band systems: the fundamental ν 4 ∼ 804.5 cm −1 (CH 37 ClF 2 )/809.3 cm −1 (CH 35 ClF 2 ) (Ross et al, 1989) in Fermi resonance with the overtone 2ν 6 ∼ 820.9 (CH 37 ClF 2 )/829.1 (CH 35 ClF 2 ) (Ross et al, 1989), and Coriolis-coupled doublets ν 3 ∼ 1108.7 cm −1 and ν 8 ∼ 1127.1 cm −1 (CH 37 ClF 2 )/1127.3 cm −1 (CH 35 ClF 2 ) (Snels and D'Amico, 2001), and ν 2 ∼ 1312.9 cm −1 (CH 37 ClF 2 )/1313.1 (CH 35 ClF 2 ) and ν 7 ∼ 1351.7 cm −1 (Thompson et al, 2002).…”

Неэмпирический анализ изотопических сдвигов и резонансных эффектов в инфракрасном спектре высокого разрешения фреона-22 (CHF-=SUB=-2-=/SUB=-Cl), обогащенного -=SUP=-13-=/SUP=-C

“…В дальнейшем в основном измерялись ИК спектры CHF 2 Cl высокого разрешения (от 0.04 до 0.0007 cm −1 ), которые были получены в газовой фазе или в сверхзвуковых молекулярных пучках для различных фундаментальных колебательно-вращательных полос при разных температурах [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Колебательно-вращательный анализ полос всех фундаментальных колебательных переходов был завершен к 2002 г. с выходом исследования по ν 2 и ν 7 [36].…”

“…Определены коэффициенты полиадного квантового числа. Проведенный анализ позволил предварительно идентифицировать центры колебательно-вращательных полос изотопологов 13 CHF 2 35 Cl и 13 CHF 2 37 Cl в спектре смеси в рамках подготовки к индивидуальным анализам колебательно-вращательных структур отдельных колебательных переходов.…”