Rotational spectra and dynamics of the van der Waals adducts of neon and argon with 1,1-difluoroethylene

Abstract

The effect of weak interactions on the ring puckering potential in the coumaran-argon van der Waals complex: Experimental and ab initio analysis of the intermolecular and low-frequency intramolecular vibrationsThe free jet millimeter wave spectra of the complexes of Ne and Ar with 1,1-difluoroethylene are reported. Information on the equilibrium configurations, dynamics, and dissociation energies of these weakly bonded complexes are obtained from their nonrigidity. The vibrational doubling ͑0.78 MHz͒ of the rotational transitions of 1,1-difluoroethylene-Ne has been useful in scaling the ab initio potential energy function calculated for the tunneling of Ne above and below the plane of 1,1-difluoroethylene. This motion is hindered by a barrier of about 36 cm Ϫ1 at the planar C 2v configuration.

Rotational spectrum, dynamics, and bond energy of the floppy dimethylether⋯neon van der Waals complex

“…Such a kind of tunneling is easier to be observed when the rare gas is a light atom, because ͑i͒ the interaction energy is smaller; ͑ii͒ a low value of the reduced mass enhances the tunneling splittings. For example doubling of rotational lines was observed in 1,1-difluoroethylene-Ne, 3 but not in 1,1-difluoroethylene-Ar. 3,4 We investigated recently the free jet millimeter-wave absorption spectra of several complexes of organic molecules with Ne.…”

“…For example doubling of rotational lines was observed in 1,1-difluoroethylene-Ne, 3 but not in 1,1-difluoroethylene-Ar. 3,4 We investigated recently the free jet millimeter-wave absorption spectra of several complexes of organic molecules with Ne. In the case of 5 or 6 membered aromatic ͑or nearly aromatic͒ rings the Ne atom was localized on one side of the ring and no tunneling effects were observed.…”

Rotational spectrum and structural analysis of CH⋯F interactions in the vinyl fluoride⋯1,1-difluoroethylene dimer

“…Transitions of the higher energy conformer may also lie in frequency ranges that contain weak transitions from other species, making pattern matching more difficult. Other unassigned species whose spectra could be present are polar conformations of the homo-dimers of VF or DFE, water complexes of either species, or neon complexes of VF (Ne…1,1-DFE has previously been studied and could be eliminated from our scans [20]). spectrometer.…”

Apparent conflicting indications on the conformation of dimethylether–argon from the rotational spectra of the d6 and 13C species

“…The potential energy surface describing the motion of Ar with respect to the partner molecule in these cases is rather flat. As a consequence, inversion splittings have been generally measured, which allowed to obtain precise information on at least one of the RG vibrational motions [7][8][9][10][11][12][13][14][15][16]. At the same time, as a consequence of these large amplitude motions, the location of Ar in the complex is obtained with a lesser precision.…”