UV SPECTROSCOPY OF THE B2A′B^{2}A' AND C2A′C^{2}A' STATES OF FCO.

(1). M. M. Maricq and J. J. Szente, Yi Su and J.S. Franeisco, J. Chem. Phys. Submitted.Author Institution: Reserch laboratory, Ford Motor Company; Lab 20, Department of Chemistry, Wayne Stale UniversityGas phase UV spectra of $FC^{16}O$ and $FC^{18}O$, produced by laser photolysis of $F_{2}$ in the presence of CO, are obtained in the region between 29000$cm^{-1}$ and $43000 cm^{-1}$(1). The three prominent progressions are assigned to the $B^{2}A^{\prime}$ and $C^{2}A^{\prime}$ states of FCO and a fourth, weaker progression may be belong to the second excited $^{2}A^{\prime}$ state. For the $B^{2}A^{\prime}$ sate, we obtained vibrational frequencies of $v_{1}=1120 \pm 40 cm^{-1}$ and $\nu_{2}=780 \pm 30 cm^{-1}$ and a zero point energy in the range $24000 < T_{0} < 27000 cm^{-1}$. The spectrum of the $C^{2}A^{\prime\prime}$ state yields $\nu_{1}=1458 \pm 6 cm^{-1}$ and $\nu_{2}=651 \pm 2 cm^{-1}$ and a zero point energy of $T_{0}=28500 \pm 25 cm^{-1}$. The electronic energies and frequencies are compared to recent {ab initio} calculations

EMISSION FROM THE PRODUCTS OF THE MULTIPHOTON DISSOCIATION OF KETENE AND ACETYL BROMIDE

Author Institution: Jet Propulsion Laboratory; Department of Chemistry, Wayne State university; Research Laboratory, Ford Motor CompanyMultiphoton excitation of ketene, $CH_{2}CO$, with 193 nm radiation produces intense fluorescence form the $A \rightarrow X$ and $B \rightarrow X$ transitions of CH radical. Weaker emission is observed with use of 308 nm radiation. Infrared multiphoton dissociation of acetylbromide, $CH_{3}C$(O)Br, produces luminescence very similar to that arising from ketene. These observations represent one of few cases of observation of ultraviolet emission following infrared multiphoton excitation of a ground state species, and supports a previous suggestion of a ketene intermediate in acetylbromide dissociation