Fourier transform infrared isotopic study of ZnC3: Identification of the ν1(a) mode

An isomer of ZnC3 with bent structure in its 1A′ electronic state has been detected in the products from the dual laser ablation of carbon and zinc rods that were trapped in solid Ar at ∼12 K. Measurements of 13C isotopic shifts have enabled the identification of the ν1(a′) asymmetric carbon stretching fundamental at 1858.9 cm−1. The experimental results are in good agreement with the predictions of DFT-B3LYP/6-311G(d) calculations that indicate a singlet bent isomer ground state structure with triplet linear and singlet cyclic isomers lying slightly higher in energy. This is the first optical detection of any isomer of ZnC3.