5999-46-2Relevant articles and documents
Analysis of cis-Difluoroethylene Ozonide by Microwave Spectroscopy and ab Initio Techniques: An Unusual Conformational Potential
Hillig, Kurt W.,Kuczkowski, Robert L.,Cremer, Dieter
, p. 2025 - 2030 (1984)
The microwave spectra of five isotopic species of cis-difluoroethylene ozonide (cis-3,5-difluoro-1,2,4-trioxolane) were assigned, including the parent, both the d1 and the d2 species, and the symmetric double-18O and the triple-18O species.A series of vibrational satellites also accompanied the ground-state transitions.The average structure consistent with this data was an ether oxygen envelope conformation having Cs symmetry, with the fluorines axial to the ring.Ab inito calculations were performed for selected values of the pseudorotational phase angle Φ to provide additional insights.They indicated that the ether envelope corresponded to the minimum-energy conformer.The potential function vs. Φ was relatively flat near the minimum and did not possess a low-energy path corresponding to the usual pseudorotation motion.Instead, the energy valley connecting puckered forms at 180, 90, and 270 deg terminates at the planar form.The ground-state conformation was discussed in terms of the balance between ring-substituent, substituent-substituent, and puckering fores.Stabilizing ring-substituent interactions dominate this interplay and are also reflected in long C-F and short C-O bond distances indicative of anomeric interactions involving the fluorine substituents.
Infrared Spectra of Hydrogen-Bonded ? Complexes between Hydrogen Halides and Acetylene
McDonald, Stephen A.,Johnson, Gary L.,Keelan, Brian W.,Andrews, Lester
, p. 2892 - 2896 (2007/10/02)
Hydrogen-bonded ? complexes C2H2--H-X have been formed by codeposition of C2H2 and HX in excess argon at 15 K and by vacuum-UV photolysis of vinyl halides.The strength of the hydrogen bond, as measured by the displacement of the H-X vibrational fundamental below the isolated HX value, decreases in the series HF, HCl, and HBr as expected.Similar complexes made from di- and thichloroethylenes give slightly higher H-Cl vibrations which show minimal interaction between the halide and the acetylene substituent.The H-F fundamentals for C2H4 and C2H2 complexes at 3732 and 3747 cm-1, respectively, show that the ? electrons in double and triple bonds are comparable hydrogen-bond acceptors.
