15min:

HOLGER S. P. MÜLLER, I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77,
D-50937 Köln, Germany; AND EDWARD A. COHEN, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099.

FClO has been proposed as an intermediate in reactions involving ClF, Cl₂O, and ClF₃O, and it has been suggested as a molecule of atmospheric interest. It has been prepared in situ by the hydrolysis of ClF₃. The pure rotational spectrum of FClO has been studied by conventional millimeter wave techniques and by microwave Fourier transform spectroscopy. Selected transitions were searched for using predictions based on an analysis of the ₁ band. Low field Stark measurements have been performed in the millimeter region. FClO is an asymmetric prolate top, = --0.8950 for F³⁵ClO, with a rather small dipole component of 0.093~(4)~D along the a-axis and a larger one of 1.93~(5)~D along the b-axis. Transitions with 0 \leq J \leq 54 and 0 \leq K_a \leq 18 were observed. Cl hyperfine splitting was generally observable throughout the spectrum with ¹⁹F spin-rotation splitting observable as well in the microwave region. Structural parameters, harmonic force constants, and nuclear magnetic shielding parameters were derived and will be compared with data of related molecules, such as ClF₃, ClF, FClO₂, and FClO₃. High resolution infrared spectra were taken in the regions of the FCl stretching mode and bending mode around 600 and 310 cm^-1, respectively. A preliminary analysis indicates that the FCl stretch, near 596.86 cm^-1 for F³⁵ClO, is in resonance with the dark overtone of near 617 cm^-1. A brief progress report will be given.