Knowledge Bank

\maketitle Results will be presented of recently initiated studieson the structures and infrared spectra of transition metal-carbon clusters that may be of interest in circumstellar shells or other astrophysical environments. The FTIR (Fourier transform infrared) spectrum of TiC$3$ was observed by trapping the vapor produced during dual Nd:YAG laser ablation of Ti and C rods in solid Ar at $\sim$10 K. Measurements of frequencies and $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}$C isotopic shifts have enabled the identification of the fan-like (\textit{C}$\mathrm{<mrow\; data-mjx-texclass="ORD">2v</mrow>}$) isomer of TiC$3$ with vibrational fundamentals \textit{$\nu$}$\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}$(\textit{a}$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$) = 624.3 and \textit{$\nu$}$\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}$(\textit{b}$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$) = 1484.2 \wn. The results are in good agreement with the predictions of DFT calculations at the B3LYP/6-311G(3\textit{df}, 3\textit{pd}) level. The observed \textit{C}$\mathrm{<mrow\; data-mjx-texclass="ORD">2v</mrow>}$ structure is also consistent with the results from an earlier photoelectron spectroscopy study.} \underline{\textbf{101}}, 7699 (1997).}