Based On Several Classes Of Fullerene Aggregate Structures, The Self-assembly And Nature Study

Supramolecular chemistry is a new branch of chemistry born in the late 1970s and it studies the properties of assemblies of molecules called supramolecular systems or supermolecules . In the last few years, due to unique physical and chemical properties supramolecular system especially supramolecular nanostructure system recently become the subject of the research activity. These fields are based on the molecular recognization, self-assembly and a new branch with"bottom-up"and"up-bottom"technology. Molecular assemblies is the subject of supramolecular chemitry. It is believed that the research of this field leads to the development of spectacular supramolecular architectures.There has been an increasing interest in design and preparation of fullerene nanostructure materials by self-organization into one-, two-, and three-dimensional supramolecular architecture because of their potential application in the promising optical device, electronic sensor, nanoscale electronics, magnetic materials and catalysis due to the high surface-to-volume ratios and small size effect. In light of their unique electronic properties, fullerene derivatives are suitable building blocks for the preparation of supramolecular system displaying photoinduced energy and electron transfer processes . Whereas research focused on the use of C₆₀ as the acceptor in covalently bound donor–acceptor pairs has received considerable attention , only a few related examples of fullerene-containing non-covalent systems have been described so far. The assembly of the two molecular components by using supramolecular interactions rather than covalent chemistry appears however particularly attractive since the range of systems that can be investigated is not severely limited by the synthetic route. As part of this research, we have recently developed a non-covalent approach based on the self-assembly of C₆₀.Supramolecular nanostructures were obtained by a layer-by-layer self-assembly procedure using fullerene without functionalization taken as acceptor, which were not only similar to photosynthesis in natural organization principles in theory but also kept symmetrically three-dimensionalπ-electrostructure of fullerene undamage. Herein, the thesis gave emphasis to several kinds of self-assembled congeries based on fullerene and its characterization investigation. Five chapters were included in present thesis.Chapter 1: The research of self-assembly of congeries based on fullerene and its characterization investigation were reviewed. Supramolecular nanostructures were obtained by a layer-by-layer self-assembly procedure using fullerene without functionalization taken as acceptor.Chapter 2: The core–shell nanospheres fullerenol–TiO₂ and C₆₀@2β-CD–TiO₂ were fabricated by a layer-by-layer self-assembly procedure seeding with fullerenols and C₆₀@2β-CD respectively, the nanospheres ranging in size from 40 to 80 nm and 10–20 nm in diameter respectively. The presence of fullerenols in the nanostructures was confirmed by XPS and FT-IR spectroscopy, and the XRD patterns proved both the titania shells on fullerenol and C₆₀@2β-CD are rutile and anatase phases.Chapter 3: C₆₀@2β-CD-PTCA-TiO₂ nanospheres and resulting hollow nanospheres were fabricated by a layer-by-layer self-assembly procedure seeding with C₆₀@2β-CD-PTCA nanoparticles. Structural and nanostructural properties have been characterized with transmission electron microscopy (TEM), thermogravimetric analycis (TGA), FT-IR spectroscopy and fluorescence spectroscopy. The obtained C₆₀@2β-CD-PTCA-TiO₂ nanospheres have perfect spherical shape with narrow size distribution (average diameter 100nm). The presence of fullerene in the hollow TiO₂ composite nanospheres was confirmed by TGA and FT-IR spectroscopy.Chapter 4: A highly water-soluble [60] fullerene inclusion complex bicapped with ethylenediamino-β-cyclodextrin was prepared, which was further used to construct uniform cubical microstructure with poly (acrylic acid). The self-assembly of [60]fullerene inclusion complex with poly (acrylic acid) was investigated by UV-Vis spectroscopic titrations, supporting a 1:1 monomeric units binding model and yielding a complex stability constant of 9.8×103M-1. The cubical microstructure and nanostructure formed with a molar ratio of amino groups / carboxyl groups about 1:2 and 1:1 were proved to be a crystalline structure by transmission electron spectroscopy measurements. Unique supramolecular system was obtained by between perylene-3,4,9,10-tetracarboxylic acid tetrakalium salt and C₆₀/β-CDa hydrochloric salt with hydrogen bonding and the electrostatic interactions.Chapter 5: Shape controllable self-assembly of melamine-[60] fullerene nanostructures were fabricated by self-assembly procedure. When molar ratio is [60] fullerene/ melamine =1: 7.4, it is found that a large amount of nanorods of minimum diameter (about 20-30 nm) were formed. But when molar ratio is [60] fullerene/ melamine =1:7.4×4 or 4:7.4, the morphologies of melamine-[60] fullerene composite are nanospheres. The molar ratio between melamine and [60] fullerene was confirmed by XPS. We discussed the effect of molar ratio between melamine and [60] fullerene on nanostructures. The charge transfer from host (melamine) to guest ([60] fullerene) was investigated by UV-Vis spectroscopy.