Absorption spectra of diatomic molybdenum nitride (MoN), molybdenum oxide (MoO), and molybdenum dimer (Mo 2) molecules isolated in Ar, Ne, and Kr matrices

MoN and MoO molecules produced in a hollow cathode discharge have been trapped in Ne, Ar, and Kr matrices at 4.2 and 13 K and investigated by optical spectroscopy. Bands attributed to MoN were identified in the red and blue spectral regions and assigned by comparison with gas phase results to the A⁴π → X⁴Σ ^- ( a) and B⁴Σ → X⁴Σ ^- ( a) transitions, respectively. The ground state of Mo ¹⁴N has been identified as ⁴Σ ^- with ω_e = 1040 cm ^-1 in an Ar matrix. Absorptions assigned to MoO in the red spectral region form the (0-0) and (1-0) bands of at least one electronic transition, but could not definitely be correlated with the gas phase results. The ground state vibrational frequency for Mo ¹⁶O in an Ar matrix is 893.5 cm ^-1. Additionally, Mo ₂ absorptions centered at 19 305 cm ^-1 were shown to be part of a vibrational progression with an average spacing of 181 cm ^-1.