Knowledge Bank

Emission spectra have been obtained during the gas-phase reaction of $F2$ with $CS2$ on substitution with carbon-13 and sulfur-34 in effort to identify the emission which lies between 550 and 880 nm. Absence of any measurable shift in the vibronic bends on substitution with carbon-13 suggests that carbon is not present in the emitting molecule and that the previous assignment to FCS should be discarded. The measured vibrational frequencies and their shifts on isotopic substitution with sulfur-34 are nearly identical to those that have been reported previously by other workers for the ground electronic state of $SF2$. Another distinct band system has been identified in this reaction system under different reaction conditions. The new bands extend from 700 nm to beyond 880 nm a show and spacing of approximately $310cm-1$. Spectra obtained in the reactions of $F2$ with OCS. $CS2/32O2$ and $CS2/36O2$ will also be presented.