Synthesis, structure and properties of (4,4′-H2bipy)[HgBr4] · H2O with strong fluorescence

(4,4′-H2bipy)[HgBr4] · H2O (1), has been synthesized via hydrothermal reaction. The title compound features an isolated structure, based on discrete 4,4′-H2bipy moieties, lattice water molecules and tetrahedral mercury atoms terminally coordinated by four bromine atoms. The 4,4′-H2bipy moieties, lattice water molecules and tetrabromo-mercury dianions are linked via hydrogen bonds. Optical absorption spectrum reveals that the presence of an optical gap of 2.53 eV, indicating that compound 1 exhibits a semiconductor property. Photoluminescent investigation reveals that the title compound displays a strong blue-light emission, which maybe originates from π → π∗ charge-transfer interaction of 4,4′-H2bipy. IR, SEM/EDS and thermogravimetry-differential thermal analyses (TG-DTA) are also presented.