Knowledge Bank

Methine and methylene, produced by UV photolysis of organic precursors in a supersonic expansion, are detected by REMPI. Rotational analysis of the E + X system of CH allows positive identification of the previously unassigned upper state as v=2 of the D $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}(\Pi i)$ state. A complex, rotationally resolved band is tentatively assigned to a previously unobserved Rydberg transition originating in the $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}A1$ state of methylene. Mechanisms for formation of these radicals are discussed.