Hydrothermal synthesis, crystal structure and photoluminescence of [HgCl2(C6NO2H5)]nn[HgCl2]n(C6NO2H5)

The first example of isonicotinic acid compounds with infinite mercury halide chains, [HgCl2(C6NO2H5)]nn[HgCl2]n(C6NO2H5) (1), was synthesized through hydrothermal reactions and structurally characterized by X-ray single crystal diffraction. Compound 1 features a one-dimensional (1-D) motif, based on infinite 1-D [HgCl2(C6NO2H5)]n chains, neutral HgCl2 moieties and isolated isonicotinic acid molecules. The [HgCl2(C6NO2H5)]n chains, HgCl2 moieties and isonicotinic acid molecules are interlinked by hydrogen bonds and π-π interactions to give a two-dimensional supramolecular layer. Photoluminescent investigation reveals that the title compound exhibits a strong emission in blue region. The emission band is identified as the π -π* transitions of the isonicotinic acid moieties.