| Summary: | 碩士 === 國立臺灣師範大學 === 化學系 === 102 === A series of organogelators and metallogelators, DU97, DU135, DU157, DU169 was designed and synthesized. These gelators are composed of ethynylanthrancene and ethynylpyrene derivatives with long-chain pyridine-2,6-dicarboxamide. These gelators have shown great ability to immobilize a variety of organic solvents to form gels. The formation of supramolecular gels is achieved from self-assembly of gelator molecules via cooperative hydrogen bonding, π-π stacking and C-H-π interactions followed by secondary interations with solvent molecules. The presence of aggregates was confirmed by variable-temperature 1H NMR and absorption/emission spectroscopy. The supramolecular aggregates in these organogels are considered to be the J-type aggregation. The xerogels studied by SEM and TEM revealed fiber-like morphologies. Among all gelators, DU97 exhibits the greatest ability to form stable gel in cyclohexane with a critical gelation concentration of 2.9 mg/mL. DU135 and DU157 containing Pt(II) metal centers exhibit unique photophysical properties. DU135 exhibits dual emission with fluorescence at 415 nm and strong phosphorescence at 655 nm. In contrast, DU157 does not show any detectable phosphorescence but only fluorescence at 438 nm. Oxygen addition product was identified for DU157 in chlorinated solvent under UV irradiation. The mechanism for the observed photochemistry likely involves singlet oxygen and proceeds with free-radical pathways.
|
|---|
