Abstract
The rotational spectrum of pentafluorobenzene has been measured by 480 MHz bandwidth chirped-pulse Fourier-transform microwave (CP-FTMW) spectroscopy. Measurement of many new transitions of the normal isotopologue (including Q-branch transitions up to J = 11 and R-branch transitions up to J = 12) has allowed the first experimental determination of Watson A-reduction centrifugal distortion constants for this species. In addition, Balle-Flygare FTMW measurements of the four unique C-13 substituted isotopologues have allowed a determination of the ring and partial fluorine atom structure of the molecule. Spectroscopic constants for the normal isotopologue are: A = 1480.86496(45) MHz, B = 1030.06911(14) MHz, C = 607.50261(9) MHz, Delta(J) = 9.0(7) Hz, Delta(K) = 65(2) Hz, and delta(J) = 2.5(4) Hz. (C) 2012 Elsevier B.V. All rights reserved.