Knowledge Bank

Gas phase UV spectra of $FC16O$ and $FC18O$, produced by laser photolysis of $F2$ in the presence of CO, are obtained in the region between 29000$cm-1$ and $43000cm-1$(1). The three prominent progressions are assigned to the $B2A\prime$ and $C2A\prime$ states of FCO and a fourth, weaker progression may be belong to the second excited $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}A\prime$ state. For the $B2A\prime$ sate, we obtained vibrational frequencies of $v1=1120\pm 40cm-1$ and $\nu 2=780\pm 30cm-1$ and a zero point energy in the range . The spectrum of the $C2A\prime \prime$ state yields $\nu 1=1458\pm 6cm-1$ and $\nu 2=651\pm 2cm-1$ and a zero point energy of $T0=28500\pm 25cm-1$. The electronic energies and frequencies are compared to recent {ab initio} calculations.