MICROWAVE SPECTRUM, STRUCTURE, AND BARRIER TO INTERNAL ROTATION OF METHYLDIFLUOROARSINE.
Loading...
Date
1961
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The spectrum of $CH_{3}AsF_{2}$ was investigated over the range 10-33 kMc/sec. Three Q-branches $(K=5\rightarrow 4, 6 \rightarrow 5, 7 \rightarrow 6)$ and two R transitions $(J=2\rightarrow 3, K=2\rightarrow 3; J=3\rightarrow 4, K=3\rightarrow 4)$ were fitted by a Hamiltonian which included terms for overall rotation, internal rotation, nuclear quadrupole coupling, and centrifugal distortion. The reciprocal moments of inertia are $A=5414.49\pm 0.04$ Mc/sec, $B=5381.28\pm 0.03$ Mc/sec, and $C=3871.88\pm 0.03$ Mc/sec. The b-axis is perpendicular to the plane of symmetry. The height of the internal rotation barrier (assumed to be sinusoidal) is $466\pm 10$ $cm^{-1}$. With the bond length $\lambda_{CH}=1.095$ {\AA} assumed, the spectral date yield $\Lambda_{AsC}=1.930\pm 0.010$, {\AA}, $\Lambda_{AsF}=1.734\pm 0.005${\AA}, $<HCH=109^\circ 9^{\prime} \pm 1^\circ$, $<CAsF=95^\circ 40^{\prime} \pm 14^{\prime}$, $<FAsF=96^\circ 18^{\prime} \pm 16^{\prime}$. The quadrupole coupling constants for $As^{75}$ are $eQq_{ee}=-220 \pm 4$ Mc/sec and $\eta_{o}=(q_{bb}-q_{aa})/q_{00}=-1.20\pm 0.05$.
Description
$^{*}$Du Pont Summer Fellow, 1956; Union Carbide and Carbon Fellow, 1957--58; National Research Council National Bureau of Standards Research Associate, 1958--59.
Author Institution: National Bureau of Standards; University of Wisconsin
Author Institution: National Bureau of Standards; University of Wisconsin