The interacting B 4Σ− and d 2Π states of CrN: A laser induced and dispersed fluorescence study

Chromium mononitride molecules have been produced in a laser vaporization molecular beam source using Cr metal and ammonia. The complex CrN LIF spectra between 430 and 490 nm have been examined in detail and representative bands in three new electronic subsystems, labeled ${\mathrm{B\hspace{0.17em}}}^4{\Sigma }^{-}{\mathrm{\leftarrow X\hspace{0.17em}}}^4{\Sigma }^{-},$ ${\mathrm{d\hspace{0.17em}}}^2{\Pi }_{\text{3/2}}{\mathrm{\leftarrow X\hspace{0.17em}}}^4{\Sigma }^{-},$ and ${\mathrm{d\hspace{0.17em}}}^2{\Pi }_{\text{1/2}}{\mathrm{\leftarrow X\hspace{0.17em}}}^4{\Sigma }^{-},$ have been rotationally analyzed. Perturbations between the ${\mathrm{B\hspace{0.17em}}}^4{\Sigma }^{-}$ and ${\mathrm{d\hspace{0.17em}}}^2\Pi$ states and their dependence on vibrational quantum numbers have been examined. Dispersed fluorescence (DF) spectra have been recorded which provided a measure of the state mixing. The DF spectra also reveal the presence of an electronic state of CrN with $\text{T∼6000\hspace{0.17em}}{\mathrm{cm}}^{\mathrm{-1}},$ identified as the ${\mathrm{a\hspace{0.17em}}}^2{\Sigma }^{-}$ state. Molecular parameters in the ${\mathrm{B\hspace{0.17em}}}^4{\Sigma }^{-},$ ${\mathrm{d\hspace{0.17em}}}^2\mathrm{\Pi ,}$ and ${\mathrm{a\hspace{0.17em}}}^2{\Sigma }^{-}$ states have been established.