15min:

LISA M. GOSS, Department of Chemistry, Idaho State University, Campus Box 8023, Pocatello ID, 83209; THOMAS A. BLAKE AND ROBERT L. SAMS, Pacific Northwest National Laboratory, P. O. Box 999, Mail Stop K8-88, Richland, WA 99352.

The jet cooled spectrum of pentafluoroethane (C₂HF₅) has been recorded between 1100. and 1325. cm^-1 at a resolution of 0.0022 cm^-1. A rotational temperature of approximately 10 K was achieved by expanding 50 Torr of C₂HF₅ in 500 Torr of helium. Transitions belonging to five different vibrations have been assigned and fit to a Watson Hamiltonian: the ₃ at 1309.88 cm^-1, the ₄ at 1200.74 cm^-1, the ₅ at 1142.78 cm^-1, the ₁₃ at 1223.33 cm^-1, and the ₁₄ at 1147.39 cm^-1. The rms deviations of the fits of the ₄ band (0.0004 cm^-1) as well as the overlapping ₅ (0.0006 cm^-1) and ₁₄ (0.0004 cm^-1) bands are in satisfactory agreement with the experimental uncertainty. The perturbations observed by McNaughton et al\footnoteD.~McNaughton~et~al., Vib. Spec. , \underline\textbf36, 123 (2004); C.~D.~Thompson~et~al., J. Mol. Spec. , \underline\textbf230, 133 (2005). are still apparent in the ₃ and ₁₃ at the rotational temperature of this study but satisfactory fits have been achieved.