Synthesis, Structures And Properties Of Functional Supramolecular Polymers From 4,4’-oxydibenzoic Acid And 4,4’-oxydiphthalic Acid

Advanced functional supramolecular systems have been payed great attention due to their enchanting structures, and potential applications in chemical bionic, fluorescent probes, catalysis, adsorption, etc. One of the important supramolecular aggregates is built up from the transition metal ions and O,N-mixed ligands. Up to date, only few examples from V-type aromatic carboxylic acids and nanosized bipyridyl analogues, have been documented.In this thesis, two V-shaped aromatic carboxylic acids with rigid-flex structures as well as various coordination modes, namely, 4,4’-oxydibenzoic acid（H2odb） and 4,4’-oxydiphthalic acid（H4odp）, are served as O-ligands; While three nanosized rigid bipyridyl analogues, namely, 1,4-bis[2-（4-pyridyl）ethenyl]benzene（bpeb）, 1,3-bis [2-（4-pyridyl）ethenyl]benzene（m-bpeb）, and 4,4’-bis [2-（4-pyridinyl） ethenyl] biphenyl（bpep） are served as N-ligands. At the same time, divalent transition metal ions, such as Zn2+, Cu2+ or Co2+ ions from their nitrates, are used as net nodes. Under solvothermal conditions, six new supramolecular polymers were synthesized,that is to say,[（H2odb） 2·（bpep） 2]n（1）, [Zn（odb）（m-bpeb）]_n（2）, [Cu2（odb）2（bpeb）]n（3）, [Co₂（odb）₂（bpeb）]_n（4）, [Zn（Hbpep）（Hodp）]n（5） and [Zn（Hbpeb）（Hodp）]n（6）. In the process of experiment, key control factors on the supramolecular assembly, such as the ratio of components, temperature, pH value, solvents, and reaction time, are investigated. Compounds 1-6 were characterized comprehensively by modern analytical instruments, for eaxample, infrared spectroscopy, thermal gravimetric analysis（TGA）, X-ray single crystal diffraction, etc. Crystal structures and luminescence are investigated.Crystal data analysis indicate that compound 3 crystallized in chiral space group（I4122, No.98）, compound 2-4 possess interpenetrated networks, and compound 3, 5 and 6 exist three-fold helical motifs. TGA results show that the compounds 1-6 have good thermal stability. Luminescent tests reveal compound 1 with green luminescence（ λem, max at 537 nm）,compound 2 with green light luminescence（ λem, max at 497 nm）, compound 5 with orange-red luminescence（ λem, max at 614 nm）, and compound 6 with yellow luminescence（ λem, max at 570 nm）. In view of thermal stability, supramolecular polymers 1, 2, 5 and 6 are new potential luminescent materials, and compound 5 especially may substitute for the europium. Above results reveal that V-type ligands are suitable the self-assembly of supramolecular systems with helical and interpenetrated motifs, nanosized and rigid building units are appropriate to organize porous architectures, and conjugate components are very important building units for luminescence supramolecular polymers.