FTIR Argon Matrix and DFT Study of the Vibrational Spectrum of SiC$_{5}$

This is the first Fourier transform infrared (FTIR) study on SiC$_{5}$, which is a part of ongoing FTIR and density functional theory (DFT) research, investigating the structures and vibrations of silicon-carbon molecules. Vibrational spectra of SiC$_{5}$ were obtained by Nd:YAG laser ablation of a sintered rod, made of $^{13}$C-enriched graphite and silicon, and trapping the resulting vapor in solid Ar at $\sim $15 K. The \textit{$\nu $}$_{4}$(\textit{$\sigma $}$_{u})$ asymmetric stretching fundamental of SiC$_{5}$ has been observed at 936.9 $\pm $ 0.2 cm $^{-1}$. The measured isotopic shifts are in good agreement with the predictions of DFT calculations. This information will help in identifying SiC$_{5}$ in circumstellar and interstellar environments. Also, it has potential applications for optoelectronic and semi-conductor devices.