Microwave spectra of eight isotopic modifications of 1-chloro-1-fluoroethylene

Study of the Vibrational Spectra and Absorption Cross Sections of 1-Chloro-1-fluoroethene by a Joint Experimental and Ab Initio Approach

“…Table 9 reports the results (rotational ground-state constants, quartic and sextic centrifugal distortion terms) obtained by using the CCSD(T)/CVTZ-ACVTZ(F) level of theory. Here the computed ground-state rotational and quartic centrifugal distortion constants are compared with the recent experimental data yielded by Leung et al, 54 while the calculated sextic distortion terms are compared with the values reported by Alonso et al 51 Concerning the ground-state rotational constants, the predicted values differ less than 0.7% with respect to the microwave data, 54 with a mean accuracy of 0.6% for both the chlorine isotopologues. Moving to the centrifugal distortion terms, the quartic ones (for both the 35 Cl and 37 Cl isotopologues) are computed with a mean deviation of 1.8% with respect to the most recent values.…”

Microwave spectrum and molecular structure of the 1-chloro-1-fluoroethylene-hydrogen fluoride complex

“…We restrict the different configurations of the complex to be planar, as observed spectroscopically for those of fluoroethylenecontaining complexes [1,[3][4][5][6][7][8][9][10][11][12] and for 1-chloro-1-fluoroethylene-HCCH [2]. The monomer geometries are held at their average values in the ground vibrational states [14,15].…”

“…The uncertainty for each coordinate given is the Costain error, which is rðrÞ ¼ 0:0015 Å 2 =jrj [20], although an argument has been made that this should be doubled for H/D substitutions [21]. The relative signs of the coordinates can then be assigned by using the known geometry of the 1-chloro-1-fluoroethylene monomer [14] and requiring that H in HF is placed at a reasonable orientation from its partner. The imaginary value of the a coordinate for C-2 indicates that this atom lies almost on the b inertial axis.…”

Accuracy Meets Interpretability for Computational Spectroscopy by Means of Hybrid and Double-Hybrid Functionals

“…We will consider, in particular, equilibrium geometries, ground state rotational constants and quartic centrifugal distortion constants, harmonic and anharmonic vibrational wavenumbers and IR intensities. The benchmark study is carried out on a set of ten molecules of atmospheric and astrochemical relevance, reported in Figure 1, which includes: difluoromethane (CH 2 F 2 ) (Carlotti et al, 1988;Tasinato et al, 2012b;Piccardo et al, 2015b), chlorofluoromethane (CH 2 ClF) (Blanco et al, 1995;Pietropolli Charmet et al, 2013), cis-1-chloro-2-fluoroethene (cis-ClHC=CHF) (Craig et al, 1970;Alonso et al, 1993;Gambi et al, 2002;Piccardo et al, 2015b), 1-chloro-1-fluoroethene (ClFC=CH 2 ) (Leung et al, 2009;Pietropolli Charmet et al, 2016;Gambi et al, 2019), chlorotrifluoroethene (F 2 C=CFCl) (Hillig et al, 1988;Tasinato et al, 2012a), oxirane (cyc-C 2 H 4 O) (Russell and Wesendrup, 2003;Flaud et al, 2012;Medcraft et al, 2012;Lafferty et al, 2013;Puzzarini et al, 2014a;Piccardo et al, 2015b), glycolaldehyde (HOCH 2 CHO) (Carroll et al, 2010;Johnson et al, 2013;Piccardo et al, 2015b;Boussessi et al, 2020a), E-ethanimine (CH 3 CHNH) (Melli et al, 2018), sulfur dioxide (SO 2 ) (Flaud et al, 1993;Mller and Brnken, 2005;Tasinato et al, 2010;Boussessi et al, 2020a), and the gauche conformer of ethyl mercaptan (CH 3 CH 2 SH) (Smith et al, 1968;Wolff and Szydlowski, 1985;Miller et al, 2009;…”