Accurate values of standard molar enthalpies of formation in condensed phases can be obtained by combining high-level quantum chemistry calculations of gas-phase enthalpies of formation with experimentally determined enthalpies of sublimation or vapourization. The procedure is illustrated for catechol, resorcinol, and hydroquinone. Using W1-F12, the gas-phase enthalpies of formation of these compounds at T = 298.15 K were computed as (-270.6, -269.4, and -261.0) kJ.mol (1), respectively, with an uncertainty of similar to 0.4 kJ . mol (1). Using well characterised solid samples, the enthalpies of sublimation were determined with a Calvet microcalorimeter, leading to the following values at T = 298.15 K: (88.3 +/- 0.3) kJ.mol (1), (99.7 +/- 0.4) kJ.mol (1), and (102.0 +/- 0.9) kJ.mol (1), respectively. It is shown that these results are consistent with the crystalline structures of the compounds. (C) 2013 Elsevier Ltd. All rights reserved.