Knowledge Bank

A band of jet-cooled $\mathrm{<mrow\; data-mjx-texclass="ORD">43</mrow>}Ti2$ has been located in the near infrared by resonant two-photon ionization $spectroscopy.1$ Rotational analysis has shown the band to be an $\Omega \prime =0\ast \leftarrow \Omega \prime \prime =1$ transition, which is consistent with the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta g$, ground state proposed by Bauschlicher $etal.2$ The band is assigned as a $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi \infty \leftarrow X3\Delta 1g$, transition, and lower and upper state bond lengths have been determined as $ru(X3\Delta g)=1.9422\pm 0.0008$ {\AA} and $ro(3\Pi u)=1.997\pm 0.009$ {\AA} ($1\Sigma$ error limits, corrected for spin-uncoupling effects). Comparisons are made to the TiV, $V2$ and $Ti2$ molecules, and a rationale for the unusual filling order of the 3d-based molecular orbitals is provided.