Poly[mu2-4,4'-bipyridine-di-mu2-bromido-cadmium(II)], with novel colour-tunable fluorescence.

The title inorganic-organic hybrid complex, [CdBr2(C(10)H(8)N(2))]n, features two-dimensional [CdBr2(4,4'-bipy)]n (4,4'-bipy is 4,4'-bipyridine) neutral networks, based on the octahedral Cd atom coordinated by four mu2-Br and two mu2-4,4'-bipy at trans positions, yielding a CdBr(4)N(2) octahedron. It crystallizes in the orthorhombic system (Cmmm). All the crystallographically independent atoms are on special positions, namely Cd on mmm, Br on mm, N on mm2, and C on sites of symmetry m or mm2. Optical absorption spectroscopy reveals the presence of an optical gap of 3.76 eV, indicating that the complex is a wide-gap semiconductor. Photoluminescence investigation reveals that the complex displays strong colour-tunable emissions, which might originate from a ligand-to-ligand charge-transfer (LLCT) transition. Thermogravimetric differential thermal analysis shows that the complex is thermally stable up to 493 K.