The structures of the (a) vinyl fluoride- and (b) 1,1,2-trifluoroethylene- complexes (, HCl, HCCH).
The geometrical parameters used in constructing the one-dimensional relaxed potential scan for trans-CHFCHF–HF. is the distance between the center of the bond and the H atom of HF. The angle between and the bond is , and is the angle between the HF molecular axis and .
A one-dimensional relaxed potential scan for trans-CHFCHF–HF in which and are optimized while is varied in 10° steps from 0° to 180° (see Fig. 2). Two additional calculations are done to locate the two minima apparent in the figure. The points are joined by a cubic spline curve.
(a) The transition for the trans-CHFCHF–HF isotopomer. Four Doppler doublets are observed, and they are due to HF nuclear spin-spin interactions (one Doppler component, the strongest line in the spectrum, is common to two hyperfine components); (b) The transition for the trans-CHFCHF–DF isotopomer. The three Doppler doublets represent hyperfine components due to deuterium nuclear quadrupole coupling interactions.
A comparison among the complexes between fluorine substituted ethylenes and HF: These figures are taken from, respectively, Refs. 1 and 9, this work, and Ref. 6.
Electrostatic potential mapped onto electron density for (a) 1,1-difluoroethylene and (b) trans-1,2-difluoroethylene. The red areas of the surfaces represent negative electrostatic potential and the blue areas positive electrostatic potential.
Structural parameters and rotational constants of two trans-1,2-difluoroethylene-HF isomers obtained from ab initio calculations.
Spectroscopic constants (in megahertz, except as otherwise noted) for six isotopomers of trans-1,2-difluoroethylene-HF. standard deviations in the parameters are given in parentheses.
Coordinates for the two C atoms in the CHFCHF subunit and the H and F atoms in the HF subunit of trans-1,2-difluoroethylene-HF.
The values of determined using HF nuclear spin-spin coupling constants and deuterium quadrupole coupling constants. standard deviations in the parameters are given in parentheses.
The values of the structural parameters of trans-1,2-difluoroethylene-HF determined by fits to the values of and of the HF- and DF-containing isotopomers. standard deviations in the parameters are given in parentheses. (These standard deviations reflect only the statistical uncertainty in the least squares fit to the geometry and do not include the effects of model errors or zero-point averaging.)
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