Vibrational fundamental and overtone spectra of C2H4 in cryogenic liquid solutions

Abstract Vibrational Fundamental and overtone transitions of C2H4 around the Δυ = 1–3 in liquid Ar, Kr, Xe and N2 solutions have been obtained using a low temperature cryostat and a Fourier transform infrared spectrophotometer for wavenumbers between 800 and 10,000 cm−1. The visible C H spectra for Δυ = 6 of ethylene in cryogenic solutions of the same solvents and liquid ethane have been measured with a low temperature cell and the thermal lens technique. Spectra in solutions show great simplification of the bands with respect to gas phase absorption bands. Assignments have been made based on gas phase transitions. Peak positions (ν), wavenumber shifts (Δν), and full widths at half maximum (Δω1/2) are reported. Changes of C2H4 frequencies in liquid Ar, Kr, and Xe seem to correlate with an increase in molar volume, dielectric constant, temperature, and polarizability of the solvents. Influence of the solvent on some fundamental vibrational frequencies are explored using the Onsager model and the polarizable continuum model (PCM). When used in conjunction with calculated anharmonic frequencies, the PCM model shows qualitative agreement with frequency shifts.