A simple Cu(II) complex, [CuII{C6H4(NH2)2}2(NO3)2] with an unprecedented hydrogen bonding supramolecular network in the solid state and its solution emission at room temperature in the visible region

The compound [CuII{C6H4(NH2)2}2(NO3)2], 1 has been prepared and characterized by spectroscopic methods and single crystal X-ray diffraction. 1 crystallizes in the orthorhombic space group Pcab (No. 61), with a=7.905 (4) Å, b=9.865 (7) Å, c=20.621 (9) Å and Z=4. The structure was solved by direct method and refined by full-matrix least-squares on F2 to R=0.0351 for 1160 reflections with I>2σ(I). In the crystal structure of 1, an extended hydrogen bonding network is formed involving copper coordinated amine and nitrato ligands. Compound 1 displays emission in solution at room temperature in the visible region furnishing the first example of an emissive transition metal complex, where the ligand is benzene-1,2-diamine (φem=0.095, τ=2.97 ns).