Jun 18, 1993 · For HF, the strain-free, saturated, and strongly cooperatively enhanced hydrogen bond pattern of the cyclic pentamer species and its nearest neighbours makes them energetically competitive with the liquid state, while their sizes are small enough to avoid too much entropic penalty in the gas phase.

Jul 15, 2000 · Rotational temperatures of 180 and 140 K have been determined for the evaporated HF monomer following dissociation of the HF pentamer and hexamer, respectively.

Based on this investigation, we develop a three-site MM model for HF, which we use to investigate the properties of liquid and supercritical HF solutions in a broad range of temperatures and pressures.

Jan 1, 2001 · If gaseous HF consists of the monomer and oligomer, it may be possible that the oligomer is the cyclic hexamer- Janzen and Bartell [12] reported that the association factor of gaseous HF is 1.96 (at 22°C), which is the equilibrium …

The present analysis of STROHMEIER and BR1EGLEB'S datats) is based largely on results at the lower pressures. It provides definite evidence for the formation of (HF)2 and (HF)6. The existence of the dimer is supported by infra-redtl'a-m spectroscopy; that of the hexamer is already well established.

herent account of the physical properties of HF vapor. From this model it of appre ia in the electron diffraction experiments, polymer species other than the cyclic hexamer may be expected to contribute negligibly to the diffraction pattern. 1. General description of the vapor It will be convenient to introduce the notation of this section by

Keller-Rudek et al.9 discussed HF association and literature data in great detail, and they referenced spectral studies indicating that HF vapor contains monomers, dimers, and cyclic hexamers.

The diffraction patterns and their dependence on temperature are best explained with the hypothesis that the monomer and a puckered, cyclic hexamer were the only appreciable constituents of the scattering vapors.

It is concluded that the relaxation mechanism of the fluorine spins is spin‐rotational interaction. The chemical shifts of both hydrogen and fluorine are strongly dependent on the pressure. This behaviour is discussed in terms of association of HF vapour to predominantly cyclic hexamers.

We present an attempt to build up a new two-body effective potential for hydrogen fluoride, fitted to theoretical and experimental data relevant not only to the gas and liquid phases, but also to the crystal. The model is simple enough to be used in Molecular Dynamics and …