Thermochemical studies for determination of the standard molar enthalpies of formation of alkyl-substituted furans and some ethers

The standard molar enthalpies of vaporization Delta(l)(g) H(m)degrees of 2,5-dimethylfuran, 2-tert-butylfuran, 2,5-di-tert-butylfuran, cyclopentenyl methyl ether, cyclohexenyl methyl ether, and tert-amyl methyl ether were obtained from the temperature variation of the vapor pressure measured in a flow system. The standard (p degrees = 0.1 MPa) molar enthalpies of formation Delta(f) H(m)degrees(l) at the temperature T = 298.15 K were measured using combustion calorimetry for 2,5-dimethylfuran, 2-tert-butylfuran, and 2,5-di-tert-butylfuran. From the derived standard molar enthalpies of formation for gaseous compounds, ring correction terms and non-nearest neighbor interactions useful in the application of the Benson group additivity scheme were calculated.