Sythesis,Structures And Properties Of Metal-organic Supramolecular Polymers From 4,4',4"-nitrilotribenzoic Acid And Styryl Bipyridine

Functional supramolecular polymers constructed through coordination bonds and intermolecular interactions are advanced materials with various structures and excellent properties.An effective way to construct novel photosensitive supramolecular polymers is integrating transition metals,the aromatic carboxylic acids and rigid N-ligands.The structures of coordination polymers not only are associated with ligands and metal centers,but aslo are affected by reaction conditions.In this thesis,two series of 14 supramolecular polymers with novel structures are assembled from divalent transition metal ions,the semi-rigid 4,4',4''-nitrilotribenzoic acid?H₃ntb?with various coordination modes as the main building unit,while three conjugate dipole aromatic styryl bipyridine,namely,1,4-bis[2-?4-pyridyl?ethenyl]benzene?p-bpeb?,1,3-bis[2-?4-pyridyl?ethenyl]benzene?m-bpeb?and 4,4'-bis[2-?4-pyri dyl?ethenyl]biphenyl?p-bpep?as the second ligands.The crystal structures were determined by single-crystal X-ray diffraction.All polymers are characterized by elemental analyses,IR spectra,X-ray powder diffraction,thermal gravimetric analyses and luminescence test.1.Eleven new 3D supramolecular polymers were constructed by the reactions between H₃ntb,p-bpeb and divalent transition metal ions under solvothermal conditions,namely,{[Cu₃?ntb?₂?p-bpeb??H₂O?₂]?H₂O?₄}_n?1?,[Cu₂?Hntb?₂?p-bpeb?]_n?2?,{[NH₂Me₂]₂[Zn₂?ntb?₂?p-bpeb?]?p-bpeb??H₂O?}_n?3?,{[Zn₂?Hntb?₂?p-bpeb?]?H₂O?₃}_n?4?,{[Zn?Hntb??p-bpeb?]?DMF?}_n?5?,[Co₆?ntb?₄?p-bpeb?]_n?6?,{[Co₂?Hntb?₂?p-bpeb?]?H₂O?₃}_n?7?,{[Co?Hntb??p-bpeb?]?DMF?}_n?8?,{[Cd?Hntb??p-bpeb?]?DMA?}_n?9?,[?H₃ntb??p-bpeb?]_n?10?,{[Ni₂?Hntb?₂?p-bpeb?₂]?H₂O?₂}_n?11?.The synthesis of supramolecular polymers 1 and 2are solvent-ratio-dependent,as the same with supramolecular polymers 6 and 7.The supramolecular polymer 1 has diamond-like network structure.Supramolecular polymers 2,4,7 and 11 have helical channels.Interestly,the supramolecular polymer 1shows a phenomenon of luminescence quenching,whlie supramolecular polymer 2emits light yellow-green luminescence,then this phenomenon reveals that the structures effect on the properties of luminescence.The self-assembly of supramolecular polymers3-5 is also solvent-dependent.The supramolecular polymer 3 shows a quite rare2D+2D?3D polycatenation,while supramolecular polymers 5,8 and 9 have stacking structure of ABAB fashion.Luminescent tests reveal compounds 3-5 and 9 with the emission peaks at 561 nm,563 nm,520 nm and 510 nm,respectively.The supramolecular polymer 6 is a?3,8?-connected 3D net.The solvothermal formation of supramolecular polymers 10 and 11 is pH-dependent.The organic supramolecular polymer 10 is a 3D network constructed through hydrogen bonds and?-?interactions,and shows orange luminescence at 594 nm,while the compound 11 has a light yellow-green luminescence at 553 nm.2.The reactions between divalent transition metal ions,m-bpeb/p-bpep and H₃ntb gave rise to three supramolecular polymers:{[Cd?Hntb??m-bpeb?]?DMA?}_n?12?,{[Zn₂?Hntb?₂?m-bpeb?]?H₂O?₂}_n?13?,{[Cd₃?ntb?₂?p-bpep??H₂O?₂]?H₂O?₂}_n?14?.The 12and 13 is coordination polymeric layers,while 14 has three-fold interpenetrated 3D networks.Luminescent tests reveal supramolecular polymers 12-14 with the maxium emission peaks at 608 nm,516 nm and 543 nm,respectively.3.Supramolecular polymer 12 shows rarely reddish-brown luminescence under the 365 nm UV irradiation.The polymethyl methacrylate?PMMA,organic glass?doped with compound 12,exhibits white luminescence under 365 nm UV irradiation.