Knowledge Bank

A new absorption spectrum, at $3327\backslash AA$, has been discovered in the flash photolysis of cyanogen azide, $NCN3$. Rotational analysis of the bands identified them as belonging to a $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Pi u\leftarrow 1\Delta g$ transition of NCN. The known $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi u\leftarrow 3\Sigma g-$ transition is also observed and its proximity, at $3290\backslash AA$, facilitates the study of the relative rates of production and disappearance of the $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Delta g-$ states. This comparison offers good evidence that the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma g-$ state is the ground state of NCN and that the main primary process under the conditions used in this study is: $NCN3\to h\nu NCN(1\Delta )+N2$