A novel trimeric Zn (II) complex based on 8-hydroxyquinoline with trifluoromethylbenzene group: Synthesis, crystal structure, photophysical properties and DNA binding

• A novel trimeric Zn (II) complex based on 8-hydroxyquinoline has been synthesized.
• The aggregation behavior was investigated by 1H NMR, UV–vis and photoluminescence.
• The interactions between 4 and C60 or EtBr–DNA system have been studied.

A novel 2-substituted-8-hydroxyquinoline ligand (E)-2-[2-(4-trifluoromethylphenyl)ethenyl]-8-hydroxyquinoline (3, HL) was synthesized and characterized by ESI-MS, NMR spectroscopy and elemental analysis. Using solvothermal method, a trimeric complex [Zn3L6] (4) was fabricated by self-assembly of Zn(II) ions with 3. X-ray structural analysis shows that 4 exhibits a trinuclear core, which was bridged and encapsulated by six 8-hydroxyquinolinate-based ligands. The supramolecular structure of 4 features a lamellar solid constructed by aromatic stacking interactions and nonclassical C–H···F hydrogen bonds derived from 4-trifluoromethylphenyl group of the 3. The coordination behavior of zinc salt and 3 in solution was performed by 1H NMR, UV–vis and Photoluminescence (PL). The experimental results show that the complex 4 emits yellow luminescence in the solid state. To investigate its properties further, we also studied the thermal stability, photophysical properties (fluorescent emission, lifetime) of complex 4, and the interactions between 4 and C60 or EtBr–DNA system.

The crystal structure of 3 and corresponding trimeric Zn (II) complex (4).Figure optionsDownload as PowerPoint slide