Ab Initio Anharmonic Force Field and Rotational Analyses of Infrared Bands of Perchloryl Fluoride

Perchloryl fluoride, FClO3, has been studied both experimentally and theoretically, using high-resolution Fourier transform spectroscopy and high-level ab initio methods. The geometry, dipole moment, and anharmonic force field of the molecule have been calculated ab initio, using the coupled-cluster with single, double, and perturbative triple excitations [CCSD(T)] level of theory. The infrared spectra of monoisotopic species have been recorded. The ν1 + ν2 bands of F35Cl16O3, F37Cl16O3, F35Cl18O3, and F37Cl18O3, the ν2 + ν3 and ν2 + ν3 − ν3 bands of F35Cl16O3 and F37Cl16O3, and the 2ν3 − ν3 band of F37Cl16O3 have been analyzed. The spectroscopic parameters obtained from these and from previous analyses have been compared with the theoretical results.