Spin-flip laser spectra of ethylene in the 2000 cm-1region

With the use of a Q-switched spin-flip Raman laser rovibrational lines of ethylene in the 2000 cm-1 region have been measured with an accuracy of the order of 0·005 cm-1. On the basis of these data and previous conventional high resolution spectra an analysis of v 7 + v 8, v 4 + v 8 and v 10 + v 8 has been performed. The results permit calculation of the harmonic and anharmonic contributions to the rotational constants of v 7 and v 7 + v 8, and allow the v 8 rotational constants to be estimated.