- The nature of cyclopentyne from different precursors
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The ratio of [2+2] and [2+4] cycloaddition products from reaction of spiro[4.2]hepta-1,3-diene with cyclopentyne depends on the source of the cyclopentyne. A mechanistic rationale for the phenomenon is presented.
- Gilbert, John C.,McKinley, Everett G.,Hou, Duen-Ren
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- Photochromic dithienylethenes characterized by: In situ irradiation NMR-spectroscopy and electrochemically induced responsiveness on gold substrates
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Photochromic compounds comprising small molecules and polymers have been shown to be of great interest in the field of stimuli-responsive materials for applications as sensors and (nano-) devices. In this regard dithienylethenes (DTEs) have been proven to be especially valuable because of their tolerance to chemicals and their good stability making them tunable and reversibly switchable between an open and a closed structure featuring different optical properties. By utilizing a potent in situ irradiation NMR spectroscopy approach, it is possible to determine the photochromic switching capability of two DTE derivatives in solution leading to crucial information about the structures, the equilibria of the chemical ring-opening and closing of the DTEs as well as the longtime stability of these molecular switches. In particular the perfluorinated thioether bearing compound shows remarkable stability with little fatigue related to the irreversibly cyclized byproduct known for DTEs. The thioether-bearing DTEs can be deprotected and used for immobilization on gold substrates which are characterized by water contact angle measurements prior to and after DTE functionalization. Finally, the electrochemically induced switching capability of the perhydro DTE is investigated by cyclic voltammetry proving its fast, quantitative and reversible cyclization. We envisage these materials for applications as sensors and optical switching devices.
- Von Irmer, Jonas,Frie?, Florian,Herold, Dominik,Kind, Jonas,Thiele, Christina M.,Gallei, Markus
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supporting information
p. 14088 - 14097
(2019/12/02)
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- A photochromic prototype based on difurylperhydrocyclopentene with remarkable photoswitching behavior and: In vivo application
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A new strategy has been developed to synthesize difurylperhydrocyclopentene derivatives. The compound displays reversible photochromism in solution and thin-film. The results show that furan is superior to thiophene in terms of strong fluorescence, higher photocyclization conversion and cyclization quantum yield, as well as better fatigue resistance. Owing to the molecule being derived absolutely from C, H, and O atoms, the compound exhibits no cytotoxicity, which enables it to potentially serve as a biodegradable and biorenewable material for in vivo applications.
- Wang, Shangshang,Zhou, Yunyun,Zhu, Liangliang,Zhang, Junji,Zou, Qi,Zeng, Tao,Chen, Wenbo
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p. 9570 - 9573
(2017/09/01)
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- 1,2-Diarylcyclopentenes as selective cyclooxygenase-2 inhibitors and orally active anti-inflammatory agents
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A series of 1,2-diarylcyclopentene methyl sulfones and sulfonamides have been shown to be remarkably potent and selective cyclooxygenase-2 (COX-2) inhibitors. The methyl sulfone analogs 7 showed excellent COX-2 activity, with IC50s ranging from
- Li,Anderson,Burton,Cogburn,Collins,Garland,Gregory,Huang,Isakson,Koboldt,Logusch,Norton,Perkins,Reinhard,Seibert,Veenhuizen,Zhang,Reitz
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p. 4570 - 4578
(2007/10/02)
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