Rotational analysis of the 7000 Å (A 3Φ→X 3#7B-Oe) electronic emission system of diatomic vanadium mononitride (VN)

The (0,0) band of the electronic emission system of the diatomic molecule VN at ∼7000 Å has been generated and rotationally analyzed. The system is 3 Φr →3 Δr and is the vanadium analog of the niobium nitride system centered ∼6029 Å. The constants for the upper and lower (almost certainly the ground) states have been determined, including estimates of the spin–orbit coupling constants, despite the absence of satellite bands. The subband origins are somewhat asymmetrically located, probably due to the interaction of the 3 Δ2 and the higher lying (by ∼3000 cm−1 ) 1 Δ2 state. There is no evidence of localized perturbations in any of the subbands. VN has the shortest bond length (r0 =1.566 Å ) observed for any diatomic molecule containing a transition metal (apart from some hydrides). The (1,1) sequence bands have also been observed but have not been rotationally analyzed at this time.