Vaporization Enthalpies of the α,ω-Alkanediols by Correlation Gas Chromatography

The vaporization enthalpies of 1,2-ethanediol through 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,4-butynediol, 2,5-dimethyl-3-hexyne-2,5-diol, and 2,5-dimethyl-3-hexane-2,5-diol are examined by correlation gas chromatography. A good correlation is observed between the mean literature values and the enthalpies of transfer from solution to the gas phase for all the α,ω-alkanediols examined. Intramolecular hydrogen bonding in the liquid phase of the smaller 1,ω-alkanediols does not appear to be very important thermochemically and appears to have a minimal effect in the gas phase as judged by the vaporization enthalpies of 1,4-butynediol, 1,4-butanediol, 2,5-dimethyl-3-hexyne-2,5-diol, and 2,5-dimethylhexane-2,5-diol. The sublimation enthalpies of the α,ω-alkanediols were calculated as the sum of the fusion and vaporization enthalpies at  T  = 298.15 K.