Rotational Raman spectroscopy of ethylene using a femtosecond time-resolved pump-probe technique.
Femtosecond Raman-induced polarization spectroscopy (RIPS) was conducted at low pressure (250 mb at 295 K and 400 mb at 373 K) in ethylene. The temporal signal, resulting from the beating between pure rotational coherences, was measured with a heterodyne detection. The temporal traces were converted to the frequency domain using a Fourier transformation and then analyzed thanks to the D2hTDS software (http://www.u-bourgogne.fr/LPUB/shTDS.html) dedicated to X2Y4 molecules with D2h symmetry. The effective Hamiltonian was expanded up to order 2, allowing the determination of five parameters with an rms of 0.017 cm(-1). Special care was taken in the precise modeling of intensities, taking into account all instrumental effects. Relative intensities were fitted (with an rms of 7.2%) and two polarizability operators were determined.
Rouzée
A
A
Laboratoire de Physique de l'Université de Bourgogne, CNRS UMR 5027, 9 Avenue A. Savary, BP 47870, F-21078 Dijon Cedex, France.
Boudon
V
V
Lavorel
B
B
Faucher
O
O
Raballand
W
W