The structures and properties of tetrafluoromethane, hexafluoroethane, and octafluoropropane using the AIMPRO density functional program

Alkane Coiling in Perfluoroalkane Solutions: A New Primitive Solvophobic Effect

“…Information on PFH may be retrieved from two spectral ranges: 1375–1025 cm –1 , the CF stretching region without a significant contribution from the n -hexane spectrum, and 1025–625 cm –1 , with strong/medium PFH bands partially overlapped with weak/very weak bands of n -hexane. There are several PFH bands that can be correlated with conformers, in particular, the CF 3 deformations at 795 and 712 cm –1 (symmetric and antisymmetric of TTT conformer) and at 816 and 731 cm –1 (symmetric and antisymmetric of TTG conformer) . As previously stated, the PFH conformer referred to as TTT is not a truly all- trans , as the F atoms are not eclipsed.…”

“…In the 3100–2700 and 1500–1400 cm –1 spectral regions, only n -hexane absorbs; the 1400–1150 cm –1 region corresponds almost exclusively to PFH bands, and in the 1000–500 cm –1 region, the two components’ bands overlap. The complete band assignment is summarized in Table S1 of the Supporting Information. ,− …”

“…There are several PFH bands that can be correlated with conformers, 47 in particular, the CF 3 deformations at 795 and 712 cm −1 (symmetric and antisymmetric of TTT conformer) and at 816 and 731 cm −1 (symmetric and antisymmetric of TTG conformer). 46 As previously stated, the PFH conformer referred to as TTT is not a truly all-trans, as the F atoms are not eclipsed. Apparently, mixing with n-hexane induced no systematic band shifts or changes in relative intensities ( Figure 2C).…”

Perfluorinated n-Alkanes CmF2m+2 (m < 7): Second pVT-Virial Coefficients, Viscosities, and Diffusion Coefficients Calculated by Means of an (n-6) Lennard-Jones Temperature-Dependent Potential

“…To obtain the factor f ( T ) of eq 2, the vibrational partition function is calculated in the harmonic oscillator approximation. In the case of CF 4 , C 2 F 6 , and C 3 F 8 the vibrational fundamental frequencies are taken from the literature. , Due to a severe lack of experimental and theoretical data the vibrational frequencies of C 4 F 10 , C 5 F 12 , and C 6 F 14 are calculated in this work (see next section).…”

Molecular Mechanics (MM4) Studies on Unusually Long Carbon–Carbon Bond Distances in Hydrocarbons

“…In Table we have listed the long C–C bonds for which we have reasonably accurate experimental results. − These distances were almost all determined by crystallographic methods, as most of them occur in fairly large molecules, where microwave and electron diffraction methods are challenging. High-level quantum-mechanical methods may be applicable now but have not been much applied as of yet to molecules of the size that we would like to study.…”