A characterisation of the complex vinyl fluoride⋯hydrogen fluoride by rotational spectroscopy and ab initio calculations

Microwave spectrum and molecular structure of the 1-chloro-1-fluoroethylene-hydrogen fluoride complex

“…Specifically, the bend in the HF complex is 24°less than that in the HCCH complex. The trends described here due to different acidic binding partner have also been generally observed when the binding partners are vinyl fluoride [3,10], 1,1-difluoroethylene [4,12], and 1,1,2-trifluoroethylene [5,11]: a change of partner from HCCH to HF shortens the hydrogen bond by 0.55 Å, 0.66 Å, and 0.73 Å, and decreases the deviation of the bond from linearity by 18°, 23°, and 28°for these three sets of complexes, respectively. The degree of these changes appears to parallel the decreasing nucleophilicity of the F atom of the substituted ethylene subunit that participates in the hydrogen bond.…”

“…We restrict the different configurations of the complex to be planar, as observed spectroscopically for those of fluoroethylenecontaining complexes [1,[3][4][5][6][7][8][9][10][11][12] and for 1-chloro-1-fluoroethylene-HCCH [2]. The monomer geometries are held at their average values in the ground vibrational states [14,15].…”

“…Our earlier work was aided by the comparison of structures, both from our own laboratory and those determined by the Legon group, for complexes of the fluoroethylenes, vinyl fluoride, 1,1-difluoroethylene, and 1,1,2-trifluoroethylene on the one hand, with a series of protic acids: hydrogen fluoride (HF) [3][4][5], hydrogen chloride (HCl) [6][7][8][9], and acetylene (HCCH) [10][11][12], on the other. In each case, as well as for trans-1,2-difluoroethylene-HF [1] and 1-chloro-1-fluoroethylene-HCCH [2], the complexes adopt a planar structure containing two non-covalent interactions: a primary, hydrogen bonding interaction between the protic acid and a fluorine atom on the substituted ethylene, and a secondary interaction, made possible by a deviation of the hydrogen bond from linearity, between a hydrogen atom in the substituted ethylene and the nucleophilic portion of the acid.…”

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

“…Previous studies of (planar) dimers of VF and DFE with HCCH [31,32] and HF [33,34] show that C-F…H distances in DFE complexes are longer than in VF complexes (2.646(11) Å vs. 2.441(4) Å for HCCH and 1.98833(44) Å vs. 1.892(14) Å for HF), consistent with the observation in the present complex of a ~0.033 Å longer C-F…H distance to the DFE fluorine atom than to the VF fluorine atom. Observed distances in VF…DFE (2.496(9) Å and 2.463 (16) Å) are very similar to the VF…HCCH distance of 2.441(4) Å, while the acid, HF, forms stronger and much shorter hydrogen bonds.…”

A chirped pulse Fourier transform microwave study of the refrigerant alternative 2,3,3,3-tetrafluoropropene

“…Building upon initial work from the Legon group, structures have been determined for the complexes formed between, on the one hand, hydrogen fluoride (HF), hydrogen chloride (HCl), and acetylene (HCCH) with vinyl fluoride [8][9][10][11], 1,1-difluoroethylene [12][13][14], and 1,1,2-trifluoroethylene [15][16][17] on the other. We have also determined the structure of the trans-1,2-difluoroethylene-HF complex [18].…”