2024-03-28T09:37:05Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/469022022-11-17T02:08:08Zhdl_2115_20051hdl_2115_144Steric effects on controlling of photoinduced electron transfer action of anthracene modified benzo-15-crown-5 by complexation with Mg2+ and Ca2+Kim, JeongsikOka, YoshikazuMorozumi, TatsuyaChoi, Eun WhaNakamura, HiroshiPhotoinduced electron transferAnthraceneSteric effectChemosensorBenzo-15-crown-5438Benzo-crown ether based chemosensors linked by an amide bond at the 1-, 2- or 9-positions of anthracene rings were synthesized. Their complexation behavior with alkaline earth metal ions in acetonitrile was investigated using fluorescence, UV, and 1H-NMR spectroscopy. In the absence of a metal ion, all compounds showed only very slight fluorescence emissions (fluorescence ‘off’ state) because of intramolecular charge/electron transfer process. After the complex formation with Mg2+ and Ca2+, however, only the 2-position analogue gave a fluorescence ‘on’ response by inhibiting the photoinduced electron transfer. Because 2- positioned anthracene was free from steric hindrance of the crown ether ring, a strongly bent complex structure was formed with Mg2+ and Ca2+, which induced a breakdown of π- conjugation between the amide moiety and the benzene ring.Elsevier LtdJournal Articleapplication/pdfhttp://hdl.handle.net/2115/46902https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/46902/3/Revised%20manuscript.pdf0040-4020AA00861787Tetrahedron6726481448192011-07-01enginfo:doi/10.1016/j.tet.2011.05.042author