Fourier-transform infrared observation of SiCn chains. I. The ν4(σ) mode of linear SiC9 in Ar at 10 K

The linear SiC9 cluster has been detected for the first time in Fourier-transform infrared spectra observed when the products from the laser evaporation of Si/C rods were trapped in Ar at ∼10 K. Comparison of 13C isotopic shift measurements with the results of density functional theory calculations (DFT) confirms the identification of the ν4(σ) mode of SiC9 at 1935.8 cm−1.