The complex [Zn(2,2'-biimidazole) 2 H 2 O] 4 (SO 4 )4·12H 2 O has been synthesised by solvothermal reaction and structurally characterised by single crystal X-ray diffraction. The zinc ion coordinates to four nitrogen atoms and one oxygen atom to yield a slightly distorted square pyramid. The [Zn(2,2'-biimidazole)2H 2 O] 2+ cations and SO 4 2anions link to each other by hydrogenbonding interactions to complete a three-dimensional supramolecular framework. The complex exhibits an emission in the blue region and theoretical investigation reveals that the emission mainly originates from ligand-to-ligand charge transfer, accompanied some ligand-to-metal charge transfer.