Rotational spectrum and structure of 1,2,3,4-tetrafluorobenzene

The rotational spectra of 1,2,3,4-tetrafluorobenzene and its three monosubstituted 13C-isotopic species were recorded in the frequency range from 2.8 to 14 GHz with a molecular beam Fourier-transform microwave (MB-FTMW) spectrometer. The centrifugal distortion analysis of the spectra yielded rotational and fourth-order centrifugal distortion constants. From the principal moments of inertia, partial rs and rm(1) structural parameters were derived. The experimental structures are compared with the results from ab initio calculations.