THE 3-PI-0U[- X 3-DELTA-1G BAND SYSTEM OF JET-COOLED TI2

A band of jet-cooled Ti-48(2) has been located in the near infrared by resonant two-photon ionization spectroscopy. Rotational analysis has shown the band to be an OMEGA' = 0+/- <-- OMEGA" = 1 transition, which is consistent with the 3DELTA(g) ground state proposed by Bauschlicher et al. [J. Chem. Phys. 95, 1057 (1991)]. The band is assigned as a 3PI0u <-- X3DELTA1g transition, and lower and upper state bond lengths have been determined as r0(X3DELTA(g)) = 1.9422 +/- 0.0008 angstrom and r0(3PI(u)) = 1.997 +/- 0.009 angstrom (1sigma 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 3PI(u) state.