Knowledge Bank

The vibrational spectra of $Si2$ $C2$ isomers have been observed for the first time in a Fourier transform infrared study of the products of the vaporization of carbon/silicon mixtures trapped in Ar at 13 K. Concurrently, linear and cyclic isomers have been studied using Hartree-Fock and second order many-body perturbation $theory.2$ Two vibrational fundamentals, $v3(b1u)=982.9$ and $v4(b2u)=382.2cm-1$, of the ground state structure, which is rhombic, have been identified. The observed frequencies, intensities, and isotopic shifts are in good agreement with the predictions of the ab initio $study.2$ Spectra for the linear ($D\omega h$) and rhomboidal $Cg$ isomers are also discussed.