Molecular Aggregation Of Two Kinds Of Water-Soluble Macrocylcic Hosts And Their Fluorescent Detection

Supramolecular chemistry is an advanced research field with unlimited vitality and good development prospects in chemistry. Cyclodextrin and calixarene, as the second and third generation supramolecular hosts, represent two important research directions in supramolecular chemistry, which have been widely applied in the molecular recognition and self-assembly. In addition, the construction of supramolecular assemblies based on π-conjugated chromophores, such as perylene bisimide and tetraphenylethene, is also a fascinating topic in chemistry and material science in recent years. However, it is still insufficient to attempt on the combination of perylene bisimide and tetraphenylethene with cyclodextrin and calixarene to fabricate various functional supramolecular architectures by covalent or non-covalent methods. Hence, we have engaged in the design and construction of supramolecular architectures through the combination of perylene bisimide and tetraphenylethene with cyclodextrin and calixarene, and further explored the corresponding properties and functions of these supramolecular architectures, such as fluorescent detection, etc. The major contents of this thesis are as follows:(1) The general aspect of supramolecular chemistry was described in brief. The new progress and important achievements on self-assemblies of cyclodextrin via π…π interaction,p-sulfonatocalixarenes-induced aggregation, functional supramolecular systems of perylene bisimide, and aggregation-induced emission (AIE) characteristics of tetraphenylethene were reviewed.(2) We successfully synthesized an asymmetrical, amphiphilic perylene bisimide-cyclodextrin conjugate PBI-CD1. Its aggregation capability and morphology were carefully examined by the combination of UV-Vis, fluorescence spectroscopy, transmission electron microscopic (TEM), scanning electron microscope (SEM), etc. By adjusting the ratio of water and methanol, its aggregation capability was controlled, while the aggregation morphology was modulated, ranging from nanorod to spherical micelle. The aggregates with different morphologies were embedded in the poly(vinylidenefluoride)(PVDF). Benefiting from benign solid-state emission exhibited by aggregates of PBI-CD1, they were further employed as solid-state fluorescence sensing for various volatile organic compounds, which showed distinguishable sensing results and excellent sensitivity for organic amines.(3) A supramolecular assembly was constructed from the π…π aggregate of perylene-bridged bis(permethyl-β-cyclodextrins) derivative PBI-CD2in water. Strong π-stacking capability of PBI-CD2was demonstrated by UV-Vis, fluorescence spectroscopy,1H NMR, etc. Furthermore, we employed the assembly embedded in PVDF membrane as solid-state fluorescence material to detect various volatile organic compounds, which exhibited compelling selectivity, sensitivity and reversibility for aniline vapor.(4) We investigated the binding behaviors of quaternary ammonium-modified perylene derivative (BPTA-PBI) and p-sulfonatocalix[n]arene (SCnA) by combination of UV-Vis and fluorescence spectroscopy, finding that SCnA could effectively induce aggregation of BPTA-PBI. The assembly morphology was further studied by electron microscope measurements, which showed nano-rod structure. X-ray Diffraction (XRD) measurements were performed to investigate the π…π stacking distances of BPTA-PBI in the presence of different p-sulfonatocalixarenes, which distinguishable stacking distances were observed.(5) We investigated the binding behaviors of quaternary ammonium-modified tetraphenylethene derivative (QA-TPE) and p-sulfonatocalixarenes (SC4A and bisSC4A) by fluorescence spectroscopy, finding that SC4A and bisSC4A could effectively induce the aggregation of QA-TPE, which resulted in aggregation-induced emission (AIE) of QA-TPE. The self-assembled fluorescent nanoparticles of the SC4A+QA-TPE and bisSC4A+QA-TPE were fabricated, demonstrated by dynamic light scattering (DLS) and electron microscope measurements. Furthermore, we could take advantage of AIE fluorescence of QA-TPE endowed by complexation of SC4A and apply photoreaction of TPE unit to manipulate fluorescence of QA-TPE by complexation and photo irradiation. In addition, the fluorescent nanoparticles were applied to detect explosive (picric acid) PA in water, showing high sensitivity with the limit of detection of7.0×10-7M for picric acid. (6) We successfully synthesized an amphiphilic bis(p-sulfonatocalixarene)s derivative (bisSC4A-12), which could form small spherical micelle in water proved by surface tension, DLS measurements, etc. Furhermore, we explored the assembly behaviors of bisSC4A-12with quaternary ammonium salt of tetraphenylethene QA-TPE, which can effectively form bisSC4A-12/QA-TPE hydrogel. The remarkable emission of the bisSC4A-12/QA-TPE hydrogel was observed by the fluorescence measurements. Moreover, temperature-dependent fluorescent experiments demonstrated that the bisSC4A-12/QA-TPE hydrogel was thermoreversible and possessed excellent thermal stability.(7) We successfully synthesized a polyethylene glycol (PEG)-modified perylene derivative (PEG-550-PBI). In water, we explored the assembly behaviors of PEG-550-PBI with α, β, γ-cyclodextrin, respectively, finding that PEG-550-PBI/a-cyclodextrin complex system could form hydrogel. The1H NMR measurements showed that the binding stoichiometries of PEG-550-PBI and a-cyclodextrin in the hydrogel were1:3.5. Moreover, the result of XRD measurement indicated that the PEG-550-PBI/a-cyclodextrin hydrogel was in the nature of hexagonal channel-type crystal structure. The confocal fluorescence image showed that the PEG-550-PBI/a-cyclodextrin hydrogel exhibited robust red fluorescence.