Knowledge Bank

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 $v1band.a$ Low field Stark measurements have been performed in the millimeter region. FClO is an asymmetric prolate top, $\kappa =-0.8950$ 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 $0\le J\le 54$ and $0\le Ka\le 18$ were observed. Cl hyperfine splitting was generally observable throughout the spectrum with $\mathrm{<mrow\; data-mjx-texclass="ORD">19</mrow>}F$ 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 $310cm-1$, respectively. A preliminary analysis indicates that the FCl stretch, near $596.86cm-1$ for $F35ClO$, is in resonance with the dark overtone of $\delta$ near $617cm-1$. A brief progress report will be given.