MICROWAVE FOURIER-TRANSFORM SPECTROSCOPY OF PERCHLORYL FLUORIDE - (FCLO3)-F-19-CL-35 37-O-16 AND (FCLO2O)-F-19-CL-35/37-O-16-O-18/

O-18-enriched, monolabeled perchloryl fluoride, (FClO2O)-F-19-Cl-35/37 -O-16-O-18, has been synthesized. Its rotational spectrum has been stu died in the 4-22 GHz region. In addition, the spectra of the symmetric isotopomers (FClO3)-F-19-Cl-35/37-O-16 have been reinvestigated. Rota tional and centrifugal distortion constants, as well as chlorine nucle ar quadrupole and chlorine and fluorine spin-rotation and spin-spin co upling constants, have been determined for the ground vibrational stat e. The ground state rotational data have been used to evaluate geometr ical parameters. The harmonic force field has been refined. The result s are compared with data of related molecules. (C) 1996 Academic Press . Inc.