The 3Π<i>u</i> ← <i>X</i> 3Δ1<i>g</i> band system of jet-cooled Ti2

Abstract

A band of jet-cooled 48Ti2 has been located in the near infrared by resonant two-photon ionization spectroscopy. Rotational analysis has shown the band to be an Ω′=0±←Ω″=1 transition, which is consistent with the 3Δg ground state proposed by Bauschlicher et al. [J. Chem. Phys. 95, 1057 (1991)]. The band is assigned as a 3Π0u ← X 3Δ1g transition, and lower and upper state bond lengths have been determined as r0(X 3Δg)=1.9422±0.0008 Å and r0(3Πu)=1.997±0.009 Å (1σ error limits, corrected for spin–uncoupling effects). Comparisons are made to the TiV and V2 molecules, a rationale for the unusual filling order of the 3d-based molecular orbitals is provided, and molecular orbital assignments are considered for the excited 3Πu state.