Poly[μ2‐4,4′‐bipyridine‐di‐μ2‐bromido‐cadmium(II)], with novel colour‐tunable fluorescence

The title inorganic–organic hybrid complex, CdBr₂(C₁₀H₈N₂)]_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 μ₂‐Br and two μ₂‐4,4′‐bipy at trans positions, yielding a CdBr₄N₂ 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.