We have investigated the energetic, structural, and other physical-chemical properties (aromaticity, intrinsic strain, hydrogen bond interaction) of 1,4-anthraquinone (1), its better known isomer 9,10-anthraquinone (2) and the derivatives 9-hydroxy-1,4-anthraquinone (3) and 9-methoxy-1,4-anthraquinone (4). In particular, the standard enthalpy of formation in the gas phase at 298.15 K of 1,4-anthraquinone was determined Δ f Hmo (g, 1) = - 4 4.9 ± 5.7 kJ mol - 1 ]. Using isodesmic/homodesmotic reaction schemes, we have experimentally estimated: (i) the stabilization energy of 1 (162.2 ± 7.2 kJ mol-1) and 2 (193.2 ± 5.2 kJ mol -1), (ii) strength of intramolecular hydrogen bonding in 3 (HB = 79.8 ± 10.8 kJ mol-1), and (iii) additional strain energy due to peri-oxygen interaction in 4 (-34.2 ± 7.6 kJ mol-1). A computational study of these species, at the B3LYP/6-311++G(3df,2p) level, sheds light on structural, aromatic, intrinsic strain, or hydrogen bond effects and further confirmed the consistency of the experimental results. © 2013 Springer Science+Business Media New York.