Investigation of the fine structure in overtone absorption bands of 12C2H4

A Fourier transform interferometer was used to record the slit-jet cooled overtone absorption spectrum of (C2H4)-C-12 between 3900 and 7900 cm(-1), at a spectral resolution of 0.02 cm(-1) and a rotational temperature of 53K. Some 17 bands were observed and rotationally analysed, leading to effective vibration-rotation constants for all upper states. Coriolis perturbations were identified and refined vibration-rotation constants were produced for seven upper states as well as for 12 Coriolis interacting dark states. Symmetry conventions different from those of the previous literature are selected in the present work.