Synthesis, Characterization And Optical Properties Of Novel Octahedral Supramolecular Cages

In this thesis,two new triangular ligands L1 and L2 were designed and synthesized by using 5-bromoisatin as the starting material.The novel octahedral supramolecular cages[L18Pd6(BF4)12](C1),[L28Cu6(ClO4)12](C2),[L28Ni6(CIO4)12](C3),[L28Pd6(BF4)12](C4),[L28Zn6(NTf2)12](C5)were successfully constructed by the self-assembly of the novel ligands L1 and L2 with the transition metal ions Cu2+?Ni2+?Zn2+?Pd2+in acetonitrile at a ratio of 8:6.The final assembly structures were characterized by 1D and 2D nuclear magnetic resonance spectroscopy(NMR),electrospray ionization mass spectrometry(ESI-MS),and traveling-wave ion mobility mass spectrometry(TWIM-MS).The optical properties of ligands and the corresponding supramolecular cages were investigated by UV-Vis spectra and fluorescence spectra(FL).The details are as follows:1.Synthesis of triangular ligands L1 and L2The novel triangular ligands L1 and L2 were obtained through Suzuki coupling reaction between compound 4 and 8/12 catalyzed by Pd(PPh3)4(Scheme 1).The new compounds L1 and L2 were confirmed by NMR,HR-MS and other characterization methods.2.Synthesis and characterization of octahedral supramolecular cagesThe novel octahedral supramolecular cages were successfully constructed by the self-assembly of the novel ligands L1 and L2 with the transition metal ions Cu2+?Ni2+?Zn2+?Pd2+in acetonitrile at a ratio of 8:6.The final assembly structures were further characterized by NMR,ESI-MS and TWIM-MS(Scheme 2).3.optical propertiesFirstly,the optical properties of the two triangular ligands L1 and L2 were studied by UV-Vis spectra and fluorescence spectra.Fluorescence spectra indicated that the two ligands featured typical AIEE(aggregation-induced emission enhancement)properties in the mixed solvent of CH3CN/Et2O.Secondly,the optical properties of supramolecular cages were investigated through UV-Vis spectra and fluorescence spectra.It was found that the fluorescence intensity had obviously quenched except for metal zinc cages in the octahedral cages.The fluorescence emission spectrum showed that the metal zinc cage C5 had good fluorescence characteristic and interesting AIEE(aggregation-induced emission enhancement)property,and it has potential application value in luminescent materials and sensing.