Syntheses and structures of tetranuclear Zn(II) complexes with in situ generated macrocyclic Schiff base ligands: Applications in Zn2+ sensing

Three novel Zn(II) complexes, [Zn4L1Cl4]·3H2O (1), [Zn4L2Cl4]·2DMF (2) and [Zn4L3Cl4]·H2O (3), have been synthesized and structurally characterized. In these complexes, interesting 32-membered dodecadentate macrocyclic ligands were generated in situ by ‘2 + 2’ type condensation reactions between a tetraamine and various dialdehydes. All the complexes are isostructurally tetranuclear Zn(II) complexes, containing endogenous alkoxo and phenoxo bridges. Applications of the macrocyclic ligands as Zn2+ sensors have been investigated. Take H4L1 for example, it exhibits a 4-fold fluorescence enhancement upon the addition of 2 equiv. of Zn2+ in MeOH.

Three tetranuclear Zn(II) complexes with in situ generated macrocyclic Schiff base ligands have been synthesized and structurally characterized, and the macrocyclic ligands have been used in fluorescent Zn2+ sensing.Figure optionsDownload as PowerPoint slide