Fourier transform infrared isotopic study of linear MnC3: Identification of the ν1(σ) fundamental

Linear MnC3 has been detected in the products from the dual laser ablation of carbon and manganese rods trapped in solid Ar at ∼12 K. The ν1(σ) vibrational fundamental, an asymmetric carbon stretching mode, has been identified at 1846.9 cm−1. Fourier transform infrared measurements of 13C isotopic shift are in good agreement with the predictions of density functional theory calculations using the mPW1PW91 functional with 6–311+G(3df) basis set. This is the first optical detection of the linear isomer of MnC3 for which previous photoelectron spectroscopy studies have reported evidence of a cyclic isomer.