2-(2-Oxazolin-2-yl)benzene-1,4-diol: X-ray and density functional theory studies

In the crystal structure of the title compound, C 9 H 9 NO 3 , there are strong intramolecular O-H...N and intermolecular O-H...O hydrogen bonds which, together with weak intermolecular C-H...O hydrogen bonds, lead to the formation of infinite chains of molecules. The calculated intermolecular hydrogen-bond energies are -11.3 and -2.7 kJ mol -1 , respectively, showing the dominant role of the O-H...O hydrogen bonding. A natural bond orbital analysis revealed the electron contribution of the lone pairs of the oxazoline N and O atoms, and of the two hydroxy O atoms, to the order of the relevant bonds.