Synthesis And Properties Of Chiral AICPL MOCs Based On Tetraphenylethylene

Tetraphenylethylene（TPE）is a typical aggregation-induced emission（AIE）fluorescence chromophore.Due to its simple structure and convenient modification,it is often used to construct various luminescent materials,such as luminescent metal-organic frameworks（LMOFs）,luminescent covalent organic frameworks（LCOFs）and luminescent metal-organic cages（LMOCs）.By introducing pyridine or formyl groups to tetraphenylethylene,tetraphenylethylene derivatives with multi-dentate coordination structure are synthesized,and then with metal ions/clusters coordination,self-assembly to form LMOCs.In order to endow the cage complex a single chiral configuration,chiral molecules can be directly introduced in the synthesis process to construct chiral aggregation-induced circular polarization luminescent（AICPL）metal-organic cages.In this thesis,we designed and synthesized a variety of chiral luminescent metal-organic cages and studied their fluorescence properties.The main content is divided into three parts:1)5,5’,5’’,5’’’-（（（ethene-1,1,2,2-tetrayltetrakis（benzene-4,1-diyl））tetrakis（methylen e））tetrakis（oxy））tetrapicolinaldehyde ligand（L）was synthesized with chiral naphthyla mine（R/S-Nap）and cadmium chloride to synthesize chiral luminescent metal-organic cages[Cd₈L₆（R-Nap）₂₄+n Cl^-]^（16-n）+（1）and[Cd₈L₆（S-Nap）₂₄+n Cl^-]^（16-n）+（2）.The cage s tructures of complexes 1 and 2 were confirmed by ESI-TOF-MS,IR and NMR.In add ition,the circular dichroism spectra and circularly polarized fluorescence spectra of co mplexes 1 and 2 are mirror images of each other.The enantioselective fluorescence re cognition of complexes 1 and 2 for penicillamine in methanol was studied.It was fou nd that the enhancement efficiency of L-（+）-β-mercaptovaline on complex 1 was great er than that of D-penicillamine,and the enhancement efficiency of D-penicillamine on complex 2 was greater than that of L-（+）-β-mercaptovaline.2)Two complexes[Cd₈L₆（Tren）₈+n（R-BPA）^-]^（16-n）+（3）and[Cd₈L₆（Tren）₈+n（S-BPA）^-]^（16-n）+（4）were demonstrated by 5,5’,5’’,5’’’-（（（ethene-1,1,2,2-tetrayltetrakis（benzene-4,1-diyl））tetrakis（methylene））tetrakis（oxy））tetrapicolinaldehyde ligand and tri（2-aminoethyl）amine（Tren）and chiral cadmium dinaphthol phosphate（R/S-BPA-Cd）.The existence of complexes 3 and 4 cage structures was demonstrated by ESI-TOF-MS,IR and NMR.In addition,the circular dichroism spectra and circularly polarized fluorescence spectra of complexes 3 and 4 are mirror images of each other.The enantioselective fluorescence recognition of complex 4 for penicillamine and carnitine in solution was studied.It was found that the quenching efficiency of L-（+）-β-mercaptovaline for complex 4 was higher than that of D-penicillamine.The quenching efficiency of D-carnitine for complex 3 is greater than that of L-carnitine,and the quenching efficiency of L-carnitine for complex 4 is greater than that of D-carnitine.3)Two chiral luminescent metal-organic cages[Ag₄（TPy PE）₂+n（R-BPA）^-]^（4-n）+（5）and[Ag₄（TPy PE）₂+n（S-BPA）^-]^（4-n）+（6）synthesized by combining tetrapyridine（3-pyridyl）ethylene（TPy PE）and chiral silver binaphthol phosphate.The cage structures of complexes 5 and 6 were demonstrated by ESI-TOF-MS,IR and NMR.At the same time,the difference between complexes 5/6 and 3/4 in the fluorescence recognition of chiral compounds was explored,and the influence of the size and shape of chiral cage complexes on the fluorescence recognition of enantiomers was verified.The experimental data indicate that complexes 5 and 6 have excellent enantiomer recognition ability for BOC-D/L-4-nitrophenylalanine,among which the quenching efficiency of D-BOCNP for complex 5 is greater than that of L-BOCNP,and the quenching efficiency of L-BOCNP for complex 6 is greater than that of D-BOCNP.However,for FMOC-D/L-nitrophenylalanine,there is almost no enantiomer fluorescence recognition ability.In contrast,complexes 3 and 4 have better enantiomer fluorescence recognition performance for FMOC-D/L-4-phenylalanine,among which,the quenching efficiency of D-FMOCNP for complex 3 is greater than that of L-FMOCNP,and the quenching efficiency of L-FMOCNP for complex 4 is greater than that of D-FMOCNP.For BOC-D/L-4-nitrophenylalanine,complexes 3and 4 showed weak fluorescence recognition.In addition,a series of covalent-organic frameworks（COFs）were constructed from borophosphonate Cage clusters,which were COF-1 based on tetra-（4-borate phenyl）ethylene（TBPE）,COF-2 based on 1,3,5-tris[（4-phenylboronic acid）]benzene（TPBAB）and COF-3 based on benzene-1,4-diboronic acid（BDA）.Their structures were characterized by PXRD and IR,and the crystal structures were simulated based on the PXRD data.The optical properties of COF-1 based on tetraphene derivatives with AIE effect were studied.