Low-temperature infrared study of sterically hindered associated alcohols

Abstract

of H20-substantially more negative than AH for the solvation of water monomer. Concluding RemarksAn important point to be made from this study is that to describe hydrogen bonding between water and the propylene carbonate solvent, wre have had to use a continuum model, wffiereas for the hydrogen bonding between water molecules in dilute solution, we have had to use a specific chemical association model. The combined infrared and nmr data conclusively eliminate cyclic trimer and suggest that an open dimer is the only

On the Existence of Free OH Groups in Liquid Water

“…It is important in this respect to recognize the fact that the OH-stretching overtones of hydrogen bonded polymers are unusually weak compared to those of the corresponding free OH groups. This has been observed in various cases by Luck and Ditter (19), Burneau and Corset (20), and ourselves (21,22). This weakness is likely to be due to decreased electric anharmonicity (21) and it makes it possible to observe free and oligomer vibrations, which do not show up in the fundamental region.…”

“…This has been observed in various cases by Luck and Ditter (19), Burneau and Corset (20), and ourselves (21,22). This weakness is likely to be due to decreased electric anharmonicity (21) and it makes it possible to observe free and oligomer vibrations, which do not show up in the fundamental region. The contribution of the free and oligomer species to the observed intensity of the overtones increases rapidly with the order of the overtones (22).…”

“…exist even at liquid nitrogen temperature in glassy matrices (21), and that in the case of liquid methanol at room temperature we also have some free and oligomeric molecules (22).…”

“…We believe that these facts add weight to the assumption that free O H groups do exist in liquid water at least at room temperature and higher temperatures. Finding "species" in liquid water is not so surprising if we have studied liquid or dissolved alcohols (21,22) and amines (28) at low temperatures, where their bands appear clearly often even at the fundamental level. The proportion of free and oligomer species must be low, however, at least at room temperature, otherwise they would show up more strongly in the fundamental region.…”

On the Hydrogen Bond Breaking Ability of Fluorocarbons Containing Higher Halogens

“…It has been also observed that in the case of aromatic amines (3,4) and alcohols (1,5) the presence of CF,Br-CF,Br lowered the degree of self-association.…”