INTRAMOLECULAR HYDROGEN-BONDING AND MOLECULAR-CONFORMATION .4. CORRECTIONS OF THERMODYNAMIC PROPERTIES OBTAINED BY IR MEASUREMENTS AT DIFFERENT TEMPERATURES AND PRESSURES

Corrections have been examined for infrared measurements of the enthal py change, Delta H, and the partial molar volume change, Delta V, for the rupture of an intramolecular hydrogen bond of some hydroxyketones and o-halophenols in dilute solutions. Expressions of Delta H and Delt a V were given by allowing for the temperature and pressure dependence s of these quantities, and the molar integrated intensities. The tempe rature and pressure coefficients of the molar integrated intensities w ere assumed to be given by experimental values of model compounds whic h are similar to the molecules concerned, but which do not exhibit con formational equilibrium. It has been found that the corrections are no t small enough to be negligible, compared with the values obtained by the usual procedures.