Self-assembly and luminescent properties of one novel tetranuclear Cd(II) complex based on 8-hydroxyquinolinate ligand

A selective fluorescent chemosensor for Cd2+ based on 8-hydroxylquinoline-benzothiazole conjugate and imaging application

A 8-hydroxylquinoline-benzothiazole conjugate (HQ-BT) was facilely synthesized by two steps with >60% total reaction yield. The HQ-BT showed a weak fluorescence that could be strongly enhanced by coordination with various metal ions such as Al³⁺, Cd²⁺, Zn²⁺ in methanol containing 1% water. Interestingly, the selectivity toward Cd²⁺ was achieved by increasing water fraction to 30% aqueous methanol solution. Thus, the HQ-BT was developed as a new and selective fluorescent chemosensor for Cd²⁺ in aqueous solution with a broad pH region 4-12. A good linear relationship between the fluorescence intensity and the Cd²⁺ concentration was found in the range of 0-5 μM with a detection limit of 0.1 μM (S/N = 3). It was also succesfully used for fluorescence imaging of Cd²⁺ in living cells.

Two 8-Hydroxyquinolinate Based Supramolecular Coordination Compounds: Synthesis, Structures and Spectral Properties

Two new Cr(III) complexes based on 2-substituted 8-hydroxyquinoline ligands, namely [Cr(L₁)₃] (1), (HL₁=(E)-2-[2-(4-nitro-phenyl)-vinyl]-8-hydroxy-quinoline) and [Cr(L₂)₃] (2), (HL₂=(E)-2-[2-(4-chloro-phenyl)vinyl]-8-hydroxy-quinoline), were prepared by a facile hydrothermal method and characterized thoroughly by single crystal X-ray diffraction, powder X-ray diffraction, FTIR, TGA, ESI-MS, UV-Visible absorption spectra and fluorescence emission spectra. Single crystal X-ray diffraction analyses showed that the two compounds featured 3D supramolecular architectures constructed from noncovalent interactions, such as π···π stacking, C-H···π, C-H···O, C-Cl···π, C-H···Cl interactions. The thermogravimetric analysis and ESI-MS study of compounds 1 and 2 suggested that the Cr(III) complexes possessed good stability both in solid and solution. In addition, the ultraviolet and fluorescence response of the HL₁ and HL₂ shown marked changes upon their complexation with Cr(III) ion, which indicated that the two 8-hydroxyquinolinate based ligand are promising heavy metal chelating agent for Cr³⁺.

Six Zn(ii) and Cd(ii) coordination polymers assembled from a similar binuclear building unit: tunable structures and luminescence properties

Six coordination polymers with different structures have been prepared. The tunable structures and photoluminescence properties were observed due to their different metal centers and supramolecular structures.