A COMPLETE STRUCTURE FOR CIS, TRANS-1,4-DIFLUOROBUTADIENE FROM MICROWAVE SPECTROSCOPY
Loading...
Date
2001
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Microwave spectra have been observed for cis, trans-1,4-difluorobutadiene, for the four $^{13}C$ isotopomers in natural abundance, and for five deuterium isotopomers in a mixture prepared by partial exchange in $NaOD/D_{2}O$. Watson-type Hamiltonians have been fitted to the a-type and b-type transitions observed for each species. For the normal species, which is a near prolate top, $A = 12988.3327(11)$, $B = 1467.8791(3)$, and $C = 1318.5845(3)$ MHz. From Stark effect measurements, the dipole moment components are $\mu_{a} = 0.660(4) D$ and $\mu_{b}=2.213(5)$ D. A Kraitchman substitution analysis succeeds for the carbon atom backbone and for the hydrogen atoms on the end carbon atoms but does not for the interior hydrogen atoms. Most notably, $I_{b}^{\prime}$ for the $2-d_{1}$ species is smaller than $I_{b}$ for the normal species. To obtain a complete structure, results of DFT calculations with the adiabatic connection method were used for the bond lengths and bond angles of the interior C-H bonds. Otherwise the agreement of experiment and theory is good.
Description
Author Institution: Oberlin College; Department of Chemistry, Oberlin College; Department of Chemistry, Kent State University; Department of Chemistry, Kent State University; Department of Chemistry, The Lubrizol Corporation