The 3ν1 + ν3 vibrational overtone spectrum of 13CH4 Original Research Article

The 3 ν1 + ν3 vibrational overtone spectrum of 13CH4 is recorded under Doppler-limited resolution conditions using a titanium sapphire laser-based photoacoustic spectrometer. Data at two temperatures, 100 and 293 K, are presented. The observed spectral congestion is qualitatively similar to that observed for 12CH4, but the detailed ro-vibrational structure of the two isotope variants is completely different. The data reflect the complicating influences of tetrahedral fine structure and vibrational state mixing.