A diamond-window high pressure cell has been used to study the effects of pressure on the OH stretching vibration of liquid alcohols. The results of this study show that: (1) while decreasing temperature changes the polymer equilibrium of hydrogen bonded systems, increasing pressure shortens the hydrogen bond or intermolecular distance without affecting the polymer equilibrium; (2) the free OH absorption seen in these compounds arises from the OH end group of the hydrogen bonded polymer and not from monomeric molecules; and (3) the alcohols used in this study must be primarily linear polymers rather than cyclic hydrogen bonded structures and these chains must be fairly short otherwise the free OH end group absorption would not be observed.
R. J. Jakobsen, Y. Mikawa, and J. W. Brasch, "High Pressure Spectroscopic Studies of Hydrogen Bonding," Appl. Spectrosc. 24, 333-337 (1970)