X-N charge density analysis of the hydrogen bonding motif in 1-(2-hydroxy-5-nitrophenyl)ethanone.

The total experimental charge density in 1-(2-hydroxy-5-nitrophenyl)ethanone (1) has been determined using high-resolution X-ray diffraction data in combination with neutron diffraction data measured at 100 K. Multipole refinement was carried out in terms of the rigid pseudoatom model. Multipole refinement converged at R = 0.026 for 5415 reflections with I > 2 sigma(I). Topological analysis of the total experimental charge density rho(r) and its Laplacian, -[symbol: see text]2 rho(r) together with a comparison against high level theoretical gas-phase calculations reveals fine details of intra- and intermolecular bonding features, in particular the extent of the pi-delocalisation throughout the molecule.