High-resolution FTIR measurement and analysis of the ν3 band of C2H3D

The high-resolution FTIR spectrum of the ν6 band of C2H3D

“…The rotational structure of the a-type transitions in the spectrum of m 6 band was similar to those of m 12 [9] and m 3 [10]. In the P and R branches, for low J values, clusters of lines of same J values were well separated and this made the initial assignments of the quantum numbers to the a-type transitions easy.…”

“…Since ground-state and upper-state (m 6 = 1) rovibrational constants up to five fourth-order centrifugal distortion constants were accurately known from previous studies [8][9][10] and the band center of m 6 could be located from the spectrum, the a-type transitions of low J values could be simulated and accurately assigned. The assignments were straightforward as the band is relatively free from local perturbations.…”

“…The ground-state constants were further refined as more assigned transitions were gradually included in the fitting procedure to expand the set of data. The same nonlinear leastsquares program for fitting asymmetric rotor spectra employed in the analyses of the m 12 and m 3 bands of C 2 H 3 D [9,10] was used for fitting the assigned transitions of the m 6 band. The program uses the Watson's Hamiltonian [14] with an I r representation in Areduction.…”

“…In the past few decades, infrared studies on the ethylene-d or C 2 H 3 D molecule were conducted with low to medium resolution [1][2][3][4][5] and with high resolution [6][7][8][9][10]. Furthermore, Hirota et al [11] used microwave spectroscopy to measure 21 transitions and their analysis of the rotational spectra of C 2 H 3 D yielded accurate ground-state rotational and centrifugal distortion constants.…”

“…The m 10 band in the 730-780 cm À1 region, and m 7 and m 8 bands in the 830-890 cm À1 regions of C 2 H 3 D were investigated separately [6,7] using a tunable diode laser spectrometer with a wavenumber accuracy better than 0.001 cm À1 . More recently, Tan et al [9] and Lebron and Tan [10] collected the FTIR spectra of m 12 and m 3 bands of C 2 H 3 D with a resolution of 0.004 and 0.0063 cm À1 , respectively in the 1240-1470 cm À1 region. From their work, accurate upperstate (m 12 = 1 and m 3 = 1) rovibrational constants of C 2 H 3 D were obtained and ground-state constants were further improved.…”