Standard molar enthalpies of formation of 2-furancarbonitrile, 2-acetylfuran, and 3-furaldehyde

The standard (p(o) = 0.1 MPa) molar energies of combustion of 2-furancarbonitrile, 2-acetylfuran, and 3-furaldehyde were measured by static bomb combustion calorimetry: the Calvet high-temperature microcalorimetry was used to measure the enthalpies of vaporization of these liquid compounds. The standard molar enthalpies of formation of the three compounds, in the gaseous phase, at T = 298.15 K, have been derived from the corresponding standard molar enthalpies of formation in the liquid phase and the standard molar enthalpies of phase transition, as (106.8 +/- 1.1) kJ . mol(-1), -(207.4 +/- 1.3) kJ . mol(-1), and -(151.9 +/- 1.1) kJ . mol(-1), for 2-furancarbonitrile, 2-acetylfuran, and 3-furaldehyde, respectively. Standard molar enthalpies of formation are discussed in terms of the isomerization ortho meta. Enthalpic increment values of the introduction of the functional groups -CN, -CHO, and -COCH3 were also compared with some other heterocycles: i.e. thiophene and pyridine. (C) 2008 Elsevier Ltd. All rights reserved.