Singlet Oxygen Generation Driven by Sulfide Ligand Exchange on Porphyrin–Gold Nanoparticle Conjugates

Here, we report a switching method of singlet oxygen (1O2) generation based on the adsorption/desorption of porphyrins to gold nanoparticles driven by sulfide (thiol or disulfide) compounds. The generation of 1O2 by photosensitization is effectively suppressed by the gold nanoparticles and can be restored by a sulfide ligand exchange reaction. The on/off ratio of 1O2 quantum yield (ΦΔ) reached 7.4. By examining various incoming sulfide compounds, it was found that the ligand exchange reaction on the gold nanoparticle surface could be thermodynamically or kinetically controlled. The remaining gold nanoparticles in the system still suppress the generation of 1O2, which can be precipitated out simultaneously with porphyrin desorption by the proper polarity choice of the incoming sulfide to restore the 1O2 generation

糖質インターフェイスを有する色素化合物の分子設計と機能化に関する研究

第1章 緒言 第2章 蛍光性分子を用いた選択的な糖質レセプターの設計と機能 第3章 フェニルボロン酸修飾スピロベンゾピランを用いる糖質レセプターの設計と機能 第4章 光応答機能を有する選択的糖質レセプターの設計と機能 第5章 結言Made available in DSpace on 2012-07-10T07:15:46Z (GMT). No. of bitstreams: 1 shinmori.pdf: 15130972 bytes, checksum: 4573a17c13f43f5e38f925ebbbef5464 (MD5) Previous issue date: 1998-10-30主1-参1工学_応化分子_分子システム工

New sugar-based gelators bearing a p-nitrophenyl chromophore: remarkably large influence of a sugar structure on the gelation ability

Three sugar-integrated gelators bearing a p-nitrophenyl group as a chromophore were synthesised. D-Mannose-based compound 3 was too soluble in most organic solvents to act as a gelator whereas D-galactose-based compound 2 was sparingly soluble in most organic solvents. D-Glucose-based compound 1 was moderately soluble and acted as an excellent gelator, gelating 10 solvents tested. The possible correlation between the gelation ability and the gelator structure is discussed on the basis of the intermolecular hydrogen-bonding interactions detectable by FT-IR spectroscopy. CD spectral measurements showed that the p-nitrophenyl groups in the gel fibrils of 1 are stacked in the clockwise direction [i.e., with (R)-helicity]. SEM observation of the xerogels showed that in most cases the gelator forms a three-dimensional network with 30–100 nm frizzled fibrils. Only when they were prepared from the methylcyclohexane solution, was the helical structure (although in part) observed. \u

Sugar integrated gelators of organic fluids: on their versatility as building blocks and diversity in superstructures

Three 1-O-methyl-4, 6-O-benzylidene derivatives of monosaccharides (D-glucose, D-galactose and D-mannose) were synthesised: they acted as versatile gelators of various organic fluids, indicating that saccharides are useful as potential building-blocks for molecular design of chiral gelators