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Construction Of Cyclodextrins Mediated Functional Porphyrin-Phthalocyanine Supramolecular Conjugates

Posted on:2015-06-30Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z Q LiFull Text:PDF
GTID:1221330467464396Subject:Organic Chemistry
Abstract/Summary:PDF Full Text Request
cyclodextrins (CDs), a class of cyclic oligosaccharides with six to eight D-glucose units, are widely used as convenient and versatile building blocks in the construction of high ordered nanoarchitectures. On the other hand, the phthalocyanine-porphyrin couples have been intensively studied during the past several decades, due to their apparent advantages to form the light-harvesting arrays with high efficiency in near-IR region. Most of the Porphyrin-Phthalocyanine Conjugates are linked by covalent bond. However, Very few quantitative studies on the Porphyrin-Phthalocyanine Conjugates are based on noncovalent. Supramolecular chemistry have unique advantages in the construction of non covalent reversible and controllable self-assembly system. In the thesis, adopt a molecular recognition strategy and supramolecular nanotechnology, we construct well ordered phthalocyanine-porphyrin supramolecular architectures through the complexation of permethylated β-cyclodextrin with porphyrin. we have constructed several porphyrin-phthalocyanine conjugates Mediated by Cyclodextrin, which are summarized as follows:1. A supramolecular nanowire originated from multivalent binding was successfully constructed by the complexation of phthalocyanine-grafted cyclodextrins and sulfonated porphyrin, in which the pristine C60could be efficiently captured by the preorganized π-electronic cavitand in water.2. In this work, considering the’orthogonal’host-guest interactions of different type cyclodextrins (CDs) towards the appropriate guest molecules and photo-induced isomerization properties of azophenyl group, we herein report a novel supramolecular spherical assembly upon complexation of a porphyrin derivative bearing azophenyl moiety and phthalocyanine-grafted β-CDs. Upon addition of naphthyl bridged bis(a-CD)s, the obtained small sized spheres could be cross-linked as relatively larger spheres through the hierarchically intermolecular organization. Moreover, the large-sized spheres could be disassembled and switched to small particles as soon as trans-azobenzene was transformed to cis-isomer upon exposure to UV irradiation. 3. The extremely strong noncovalent complexation between the rigid host of phthalocyanine-bridged β-cyclodextrins and amphiphilic guest of carboxylated porphyrin is employed to construct a hollow tubular structure as supramolecular nanoreactor. The representative coupling reaction can continuously occur in the hydrophobic interlayers of tubular walls in pure water at room temperature, leading to10times higher enhancement of reaction rate without any adverse effect in catalytic activity and positive conversion.4. The extremely strong noncovalent complexation between the rigid phthalocyanine-bridged β-cyclodextrins and amphiphilic porphyrins is employed to construct a hollow tubular structure as a reusable soft template. This supramolecular tubule can be repeatedly used to guide the synthesis of uniform Ag nanowire, which exhibits the high-performance surface-enhanced Raman scattering ability with a higher enhancement factor value.
Keywords/Search Tags:cyclodextrin, porphyrin, phthalocyanine, molecular assembly, organicnanotube, template
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