Rotational analysis of the red electronic emission spectrum of molybdenum nitride (MoN)

A system of emission bands in the red region of the optical spectrum has been identified as due to the species MoN. The system was generated by the microwave (2450 MHz) excitation of a flowing mixture of MoCl₅ and molecular nitrogen in a stream of helium but is also observed in a DC arc in air between molybdenum electrodes. One of the Q-form branches has previously been assumed to be an atomic line of Mo I. The system has been assigned as the 0, 0 band of a ⁴Π(a) → X⁴Σ⁻(a) transition, with a large zero-field splitting of the ground ⁴Σ⁻ term (86 cm⁻¹). A preliminary search has been made to detect the presence of MoN in M-type stars.