Vibration—rotational Raman spectra of acetylene, 12C 2H 2

Abstract

The vibration—rotational Raman spectra of the ν 1 (Σ + g ), ν 2(Σ + g ) and ν 4(Π g ) bands of acetylene, 12C 2H 2, have been analysed and vibration—rotation constants ν o , α and q have been calculated with a precision similar to, and often better than, the best Raman and i.r. values available. Analyses of the resolved vibrational—rotational hot bands (ν 1 + ν 1 4 - ν 1 4), (ν 1 + ν 1 5 - ν 1 5) have also been carried out. Using the best Raman and i.r. values of the rotational and vibration—rotational constants for the 12C 2H 2 and 12C 2D 2 species the bond lengths r e (CC) and e (CH) have been calculated.