15min:

MICHAELEEN R. MUNROW, S. RANGANATHAN, STEWART E. NOVICK, Department of Chemistry, Wesleyan University, Middletown, CT 06459; DEAN ANTIC, JOSEF MICHL, Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309.

Nitrogen matrix IR spectroscopy and ab ~initio calculations of three distinct conformations of perfluoro-n-butane, n-C₄F₁₀, have recently been reported. We have measured the Fourier Transform microwave spectrum of the gauche conformer of perfluoro-n-butane and determined the C-C-C-C dihedral angle to be ~ 51^\circ. This is in good agreement with the ab ~initio calculations of Albinsson and Michl that predicted dihedral angles of 54^\circ, 95^\circ, and 165^\circ, for the gauche, ortho, and anti conformations, respectively. The search for the other conformations continues. In addition, the spectrum of the symmetric top isomer, perfluoroisobutane, has been observed.