Controllable supramolecular structures and luminescent properties of unique trimeric Zn(II) 8-hydroxyquinolinates tuned by functional substituents

We reported here the self-assembly of two supramolecular structures based on similar trimeric Zn(II) units that are built from novel 2-substituted 8-hydroxyquinoline ligands and coordination Zn(II) ions. The aggregation behavior of zinc salt and ligand in solution was investigated by a variety of techniques, including H-1 NMR, UV-vis and photoluminescence (PL). In the solid state, the supramolecular structures can be controlled by the substituted groups (-NO2 and -F) via intermolecular interaction, such as pi center dot center dot center dot pi stacking, C-H center dot center dot center dot O, and C-F center dot center dot center dot F-C interactions. As a result, the two trimeric Zn(II) complexes exhibit disparate photophysical properties. The present research holds great promise in the development of novel multinuclear Zn(II) materials, and may contribute to the understanding of structure-property relationships.