SPECTROSCOPY OF MNF - ROTATIONAL ANALYSIS OF THE A(7)PI[-X(7)SIGMA(+) (0, 0) AND (1, 0) BANDS IN THE NEAR-ULTRAVIOLET REGION

Jet-cooled fluorescence excitation spectra of the (0, 0) and (1, 0) bands of the A7∏ ← X7∑+ system of MnF have been recorded and rotationally analyzed. The MnF molecules were generated by chemical reaction in a plasma produced by laser vaporization, and rotationally cooled to about 20 K by supersonic expansion. The majority of the 106 assigned branches and features are shown to belong to satellite transitions. Most of the total intensity arises from transitions involving the lowest spin components (F1, F2, and F3) of the X7∑+ state, particularly the F1 component. A set of molecular parameters has been derived for the states involved, using appropriate effective Hamiltonian matrix representations. Third- and fourth-order spin-orbit parameters η and θ are found to be necessary in the description of the A7∏ state. Results are discussed in terms of the leading configurations of the X7∑+ and A7∏ states. The possibility that the A7∏ state is not the lowest lying excited state in the septet manifold is raised. © 1993 Academic Press, Inc.