15min:

NORMAN C. CRAIG, CHRISTOPHER F. NEESE AND DEACON J. NEMCHICK, Department of Chemistry and Biochemistry, Oberlin College, Oberlin, OH 44074; MICHAEL LOCK, Physikalish-Chemisches Institut der Justus Liebig Universität, Heinrich-Buff Ring 58, D-35392, Giessen, Germany.

A mixture of deuterium isotopomers of trans,trans -1,4-difluorobutadiene (ttDFBD) was prepared by partial exchange with NaOD/D₂O. A prominent component of the mixture was the 1- d ₁ species. The rotational structure in a C-type band of this species centered at 920.5 cm^-1 was analyzed in the high-resolution (0.002 cm^-1) infrared spectrum. The analysis of this band was compromised by large contributions from a C-type band at 893 cm^-1 in the spectrum of ttDFBD-1,4- d ₂. Provisional ground state rotational constants for ttDFBD-1- d ₁ are reported. We have recently shown that 1-fluoroethylene can be exchanged with NaOD/D₂O to give 1-fluoroethylene-1- d ₁, which can be used in known chemistry to make pure DFBD-1- d ₁. An improved high-resolution infrared spectrum of ttDFBD-1- d ₁ will be obtained. This method will also yield cis,cis -DFBD-1- d ₁ for investigation. Rotational constants for ttDFBD-1- d ₁ and ccDFBD-1- d ₁ are needed for determining the semi-experimental equilibrium structures of the two nonpolar isomers of DFBD.