Quinoline N-oxide dihydrate from powder data

The structure of quinoline N-oxide dihydrate, C₉H₇NO·2H₂O, has been determined from X-ray powder diffraction data, using grid search technique and a bond-restrained Rietveld refinement. The structure features an interesting system of co-operative hydrogen bonds, which apparently involves all four `active' H atoms, and is based on the infinite chains formed by two alternating symmetry-independent water mol­ecules. The chains are further interlinked through two more symmetry-independent hydrogen bonds which make use of the N-oxide O atom as hydrogen-bond acceptor.