Preparation, structure, fluorescence and TDDFT calculation of a zinc biimidazole complex

Abstract

The complex [Zn(2,2'-biimidazole)2H2O] 4(SO4)4.12H2O 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 2O]2+ cations and SO42- anions 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.