Infrared Spectra in the 3 μm Region of Ethane and Ethane Clusters in Helium Droplets

Abstract

Ethane and ethane clusters (N ≈ 10(2)-10(4)) were studied inside helium droplets with infrared laser spectroscopy. The spectra were measured in the 2880-3000 cm(-1) range, which covers the ν5, ν(8+11), and ν7 vibrational bands of ethane. Partially resolved rotational fine structure in the spectrum of the monomer reveals solvent-induced band origin blue shifts that are each approximately 1 cm(-1). The effective B(He) and A(He) rotational constants were found to be reduced by 52% and 16% in comparison to their gas phase values, respectively. Spectra of the clusters show the same three bands shifted toward low frequency by approximately 10 cm(-1) because of intermolecular interactions in the clusters. The spectra of the ethane clusters are dominated by the ν7 band, whereas the relative intensities of the ν5 and ν(8+11) bands are about a factor of 5 weaker than for single molecules or for solid ethane, the spectrum of which is also reported here.

Reactive intermediates in 4He nanodroplets: Infrared laser Stark spectroscopy of dihydroxycarbene

“…[62][63][64][65][66][67] Therefore, the excellent agreement between theory and experiment observed here provides strong confidence in the above assignments. These assignments imply rather large FIG.…”

Infrared rovibrational spectroscopy of OH–C2H2 in 4He nanodroplets: Parity splitting due to partially quenched electronic angular momentum

“…Indeed, distortion constants derived from spectra of He-solvated molecules and complexes are often substantially larger than the associated gas-phase values, [13][14][15] an effect which has been discussed in detail. 16,17 The Hamiltonian used to model the rotational energy level pattern of He-solvated OH-C 2 H 2 is given beloŵ…”

“…A so (CASSCF)/cm −1 A so (MRCI)/cm −1 (9,7) 134.96 132.49 (9,8) 134.96 132.46 (9,9) 134.97 132.42 (11,10) 134.97 132.42 (17,13) 134 geometry. The active spaces were gradually increased to the full valence active space (17 electrons in 15 orbitals) to investigate the convergence of the calculated A SO .…”

Large amplitude motion of the acetylene molecule within acetylene–neon complexes hosted in helium droplets

“…8 Its two rotational constants B isolated = 0.66 cm À1 and A isolated = 2.67 cm À1 fall approximately in the two limiting cases mentioned above. The smaller one, B, is reduced by 52% in the droplet environment whereas the larger one, A, is reduced by only 16%.…”