The Ethylene-Carbon Dioxide Complex and the Double Rotor Model.

Authors :: McKellar ARW
Moazzen-Ahmadi N
Source :: The journal of physical chemistry. A [J Phys Chem A] 2020 Jan 30; Vol. 124 (4), pp. 684-689. Date of Electronic Publication: 2020 Jan 21.
Publication Year :: 2020
Abstract: The infrared spectrum of the weakly bound C <subscript>2</subscript> H <subscript>4</subscript> -CO <subscript>2</subscript> complex is investigated in the region of the ν <subscript>3</subscript> fundamental band of CO <subscript>2</subscript> (≈2350 cm <superscript>-1</superscript> ), using a tunable OPO laser source to probe a pulsed supersonic slit jet expansion. The spacing of the various K -subbands in this perpendicular (Δ K = ±1) spectrum is very irregular, and the pattern of irregularity is quite different from that observed previously in another C <subscript>2</subscript> H <subscript>4</subscript> -CO <subscript>2</subscript> band by Bemish et al. [ J. Chem. Phys. 1995 , 103 , 7788 ]. But by allowing for the different symmetry of the ν <subscript>3</subscript> (CO <subscript>2</subscript> ) upper vibrational state, both results can be strikingly well explained using the "double internal rotor" model as described by Bemish et al.