Knowledge Bank

Complexes consisting of a rare gas atom bound to a neutral free-radical provide prototype systems for the study of weak bonding interactions. In particular, when the radical possesses a permanent dipole moment, the relative importance of electrostatic interaction (dispersion forces) and chemical bonding (significant orbital overlap) can be qualitatively assessed. Spectroscopic data $(0,1cm-1$ resolution) for the vinoxy -Ar $(C2H3O-Ar)$ complex has been partially analyzed to obtain structural information. The Ar is quite tightly bound, but the geometry is consistent with the dominance of electrostatic interactions. Studies of this complex at higher resolution, and attempts to observe the $C2H3O-Ne$ complex are currently in progress. We are also examining the possibility of obtaining information about the weak bonding interaction by observing their effects on the spin-orbit coupling in triatomic adducts. The van der Waals complexes of SH and OH are useful model systems for this purpose, and we are searching for the electronic spectra of these adducts. A summary of the progress achieved in these studies will be presented.