The application of correlation gas chromatography to some problematic thermochemical properties

This thesis focuses on the measurement of thermodynamic properties of organic compounds such as vaporization enthalpy and vapor pressure. Some of these measurements were performed on system for which these properties could not be measured directly. A method developed previously, correlation gas chromatography, has been used to measure these properties. The compounds of interest in this study are described below.;Acetylacetone and ethyl acetoacetate are compounds that exist in the form of two tautomers. Two keto-enol tautomers are present in both the gas and condensed phase in significant amounts. Acetylacetone exists in two forms, 2,4-pentanedione and (z)-4-hydroxy-3-penten-2-one. Ethyl acetoacetate exists as ethyl-Z-3-hydroxy-2-butenoate and ethyl 3-oxobutanoate in equilibrium. The vaporization enthalpy of the mixtures measured previously, are significantly different from the values obtained when each component is measured separately. The difference is attributed to an endothermic enthalpy of mixing that destabilizes the mixture relative to the pure components. This significantly effects the enthalpy of formation of these materials previously measured.;Both intramolecular and intermolecular hydrogen bonding of alpha,o-alkanediols are present in the condensed phase. The measurement of the vaporization enthalpies of these compounds was performed to determine if there is any effect of intramolecular hydrogen bonding on the vaporization enthalpy. Intramolecular hydrogen bonding of the small 1,o-alkanediols, appears to have a minimal effect in the gas phase as determine by the measurements of the vaporization enthalpy of 1,4-butynediol, 1,4-butanediol, 2,5-dimethyl-3-hexyne-2,5-diol, and 2,5-dimethylhexane-2,5-diol, systems which can and cannot intramolecularly hydrogen bond.;The vaporization enthalpies and vapor pressures of a series of unsaturated fatty acid methyl esters, FAMEs, derived from many oils and fats and now used in mixtures as biofuels, have been measured and completed in this study. A series of saturated FAMEs had been measured previously by our group.;The vaporization enthalpy and fusion enthalpy of 1-indanone, 2-indanone and 1,3-indanedione has been measured. This work is a contribution to other thermochemical measurements on these compounds which had been performed in collaboration with colleagues at the University of Porto.;Deuterated compounds are of interest since they are frequently used as reference compound in various analytical measurements, particularly in combination with mass spectrometry. Their vapor pressures and vaporization enthalpies are therefore of interest. Since they can be separated from their hydrocarbon analogs by gas chromatography, the vapor pressures and vaporization enthalpies of a series of commercially available deuterated materials have been measured.