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231.
Five‐State Molecular Shuttling of a Pair of [2]Rotaxanes: Distinct Outputs in Response to Acid and Base Stimuli
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Masahiro Ueda Shoya Terazawa Yasuaki Deguchi Masaki Kimura Naoki Matsubara Shinobu Miyagawa Tsuneomi Kawasaki Yuji Tokunaga 《化学:亚洲杂志》2016,11(16):2291-2300
In this study we synthesized two acid‐/base‐controllable [2]rotaxanes featuring aminodiazobenzene and aminocoumarin units, respectively, as chromophores and dibenzo[24]crown‐8 and dibenzo[25]crown‐8 units, respectively, as their macrocyclic components. Each [2]rotaxane contained N‐alkylarylamine (ammonium) and N,N‐dialkylamine (ammonium) centers as binding sites for their crown ether components. The absorption patterns of the chromophores were dependent on the position of the encircling macrocyclic component and the degree of protonation, with three distinct states (under acidic, neutral, and basic conditions) evident for each [2]rotaxane. The mixed [2]rotaxane system displayed stepwise and independent molecular shuttling behavior based on the degree of protonation of the amino groups in response to both the amount and strength of added acids or bases; as such, the system provided five different absorption signals as outputs that could be read using UV/Vis spectroscopy. 相似文献
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Masaki Kita Eric R.O. Siwu Takahiro Takiguchi Tomoyuki Koyama Takeshi Iwashita Daisuke Uemura 《Tetrahedron letters》2007,48(19):3429-3432
Durinskiol A (1) is a long carbon-chain polyol compound with a molecular weight of 2128 mu isolated from the symbiotic dinoflagellate Durinskia sp. The relative stereochemistries of ether rings and sugar moieties in 1 were established based on 2D-NMR analysis and molecular modeling studies. Conformational analysis of the 6,5,6-bis-spiroacetal ring in 1 was also examined by using ab initio methods. 相似文献
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Masaki Kita Eric R.O. Siwu Takahiro Takiguchi Kaoru Yamada Takeshi Iwashita 《Tetrahedron letters》2007,48(19):3423-3427
A long carbon-chain polyol compound with a molecular weight of 2128 mu, durinskiol A (1) was isolated from the cultured symbiotic dinoflagellate Durinskia sp. Its planar structure was elucidated based on 2D-NMR and MS/MS analysis. Durinskiol A (1) caused a short body length, abnormal pigment pattern, and pericardiac and yolk-sac edema in zebrafish. 相似文献
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Anjima H Tsukamoto S Mori H Mine M Klobukowski M Miyoshi E 《Journal of computational chemistry》2007,28(15):2424-2430
We developed new model core potentials (MCPs) for s-block elements from Na to Ra, in which the outer core (n-1)s and (n-1)p electrons are treated explicitly together with the ns electrons. By adding suitable correlating functions, we demonstrated that the present MCP basis sets show excellent performance in describing the electronic structures of atoms and molecules, bringing about accurate ionization potentials of atoms and very good spectroscopic constants of ionic and covalent molecules. The results obtained with the new MCPs are very close to the ones obtained using the all-electron correlation consistent basis sets of Dunning. 相似文献
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Structural characterization of the fleeting ferric peroxo species in myoglobin: experiment and theory 总被引:1,自引:0,他引:1
Unno M Chen H Kusama S Shaik S Ikeda-Saito M 《Journal of the American Chemical Society》2007,129(44):13394-13395
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