Calorimetric and Computational Study of 3-Buten-1-ol and 3-Butyn-1-ol. Estimation of the Enthalpies of Formation of 1-Alkenols and 1-Alkynols

The enthalpies of combustion and vaporization of 3-buten-1-ol and 3-butyn-1-ol have been measured by static bomb combustion calorimetry and correlation gas chromatography techniques, respectively, and the gas-phase enthalpies of formation, Δf H°m(g), have been determined, the values being −147.3 ± 1.8 and 16.7 ± 1.6 kJ mol-1, for 3-buten-1-ol and 3-butyn-1-ol, respectively. High level calculations at the G2 and G3 levels have also been carried out. Relationships between the enthalpies of formation of 1-alkanols, 1-alkenols and 1-alkynols and with the corresponding hydrocarbons have been discussed. From the calculated contributions to Δf H°m(g) for the substitutions of CH3 by CH2OH, CH3CH2 by CH2CH and CH3CH2 by CH⋮C, we have estimated the Δf H°m(g) values for 3-buten-1-ol and 3-butyn-1-ol, in excellent agreement with the experimental ones. Δf H°m(g) values for 1-alkenols and 1-alkynols up to 10 carbon atoms have also been estimated.