Vibrational frequencies and structural determinations of tert-butylacetylene

The normal mode frequencies and corresponding vibrational assignments of tert-butylacetylene (TBA) are examined theoretically using the Gaussian 98 set of quantum chemistry codes. All normal modes were successfully assigned to one of the nine types of motion (C---C stretch, CC stretch, C---H stretch, C---C---C bend, CC---C bend, CC---H bend, H---C---H bend, CH₃ rock, and CH₃ twist) utilizing the C_3v symmetry of the molecule. Calculations were performed at the Hartree–Fock, B3LYP, and MP2 levels of theory using the standard 6-311G^** basis. Theoretical results were successfully compared against available experimental data.