Fourier transform infrared isotopic study of the ν4 and ν5 stretching modes of linear C6 in Ar at 10 K

The vibrational spectrum of the linear C6 cluster produced by trapping the products of the high temperature evaporation of graphite in Ar at ∼10 K has yielded a complete set of measurements of the ν4(σu) and ν5(σu) stretching modes for all possible 13C-substituted isotopomers. The observed isotopomer frequencies are in excellent agreement with the predictions of recent second-order, Mo/ller–Plesset, ab initio calculations.