A 1 : 1 co-crystal of quinol and pyridine

A co-crystal of quinol and pyridine would be expected to form with 1:2 stoichiometry because quinol has two hydrogen-bond donors and pyridine has one hydrogen-bond acceptor which is more basic than phenolic oxygen. We report the structure of a 1:1 co-crystal, viz. quinol-pyridine (1/1), C6H6O2.C5H5N, which does not conform to this expectation. Its stability appears to imply that a combination of individually relatively weak C-H...O, C-H...pi and pi-pi stacking interactions are energetically competitive with O-H...N hydrogen bonds. Quinol molecules lie on inversion centres, while pyridine is in a general position