Chemical reactions were used to synthesize 2,11,20-tris(ethanedithia)-9,18,27-trimethoxy-6,15, 24-tri-tert-butyl[3.3.3]metacyclophane 2 and 2,11-bis(ethanedithia)-9,18,27-trimethoxy-6,15,24-tri-tert-butyl[3.3.3]metacy...Chemical reactions were used to synthesize 2,11,20-tris(ethanedithia)-9,18,27-trimethoxy-6,15, 24-tri-tert-butyl[3.3.3]metacyclophane 2 and 2,11-bis(ethanedithia)-9,18,27-trimethoxy-6,15,24-tri-tert-butyl[3.3.3]metacyclophane 4 from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]meta-cyclophane-2,11,20-trione 1 and -2,11-dione 3. The yields of 2 and 4 were 70% and 81% respectively. The conformations of the synthesized compounds 2 and 4 were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Compounds 2 and 4 were found to have a partial-cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partial-cone conformation for the two products, 2, 4. During the variable temperature nuclear magnetic resonance spectroscopic studies, compound 2 was found to have a coalescence temperature of about 0?C. Extraction of silver ions with compound 2 gave an extractability of 82% while the parent compound 1 showed zero (0) silver affinity. A 1:1 mol/mol mixture of compound 2 and silver ions studied by solution 1H NMR revealed a novel “Molecular Roulette” type of motion.展开更多
Various [3.3.3]metacyclophane derivatives were synthesized from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy [3.3.3] metacyclophane-2,11,20-trione 1 using simple chemical reactions. The conformations of the synthesized c...Various [3.3.3]metacyclophane derivatives were synthesized from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy [3.3.3] metacyclophane-2,11,20-trione 1 using simple chemical reactions. The conformations of the synthesized compounds were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Two of the synthesized compounds 5, 6, were found to have a partial cone conformation with the third, 4, having the cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partialcone conformation for the two products, 5, 6. During the variable temperature nuclear magnetic resonance spectroscopic studies, 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]metacyclophane-2,11,20-triol was found to have a coalescence temperature of about 0?C.展开更多
A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescenc...A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescence emission, with a large Stokes shift(λex/em = 357 nm/505 nm, Δλ = 148 nm), which helps to avoid interference in excitation and emission. For the metal ions tested, the fluorescence of Compound 2 was quenched only by Fe3+ and Cr3+ ions. Evidence for the hydrolysis reaction promoted by the metal ions is given by X-ray crystallography, mass spectra(MS), infrared(IR) spectra, and fluorescence spectroscopy data.展开更多
The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) inaqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electron...The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) inaqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronicand geometric structure of substrate. In the cases of o-benzenedimethanol (1a) and m-benzenedimethanol (1b), theIBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation ofthe catalytic activity of Q[8] when p-benzenedimethanol (1c) is subjected to the IBX oxidation. The additionamount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidationmuch more. The investigation of host-guest interactions by isothermal titration calorimetry implies the supramolecularcatalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril.展开更多
文摘Chemical reactions were used to synthesize 2,11,20-tris(ethanedithia)-9,18,27-trimethoxy-6,15, 24-tri-tert-butyl[3.3.3]metacyclophane 2 and 2,11-bis(ethanedithia)-9,18,27-trimethoxy-6,15,24-tri-tert-butyl[3.3.3]metacyclophane 4 from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]meta-cyclophane-2,11,20-trione 1 and -2,11-dione 3. The yields of 2 and 4 were 70% and 81% respectively. The conformations of the synthesized compounds 2 and 4 were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Compounds 2 and 4 were found to have a partial-cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partial-cone conformation for the two products, 2, 4. During the variable temperature nuclear magnetic resonance spectroscopic studies, compound 2 was found to have a coalescence temperature of about 0?C. Extraction of silver ions with compound 2 gave an extractability of 82% while the parent compound 1 showed zero (0) silver affinity. A 1:1 mol/mol mixture of compound 2 and silver ions studied by solution 1H NMR revealed a novel “Molecular Roulette” type of motion.
文摘Various [3.3.3]metacyclophane derivatives were synthesized from 6,15,24-tri-tert-butyl-9,18,27-trimethoxy [3.3.3] metacyclophane-2,11,20-trione 1 using simple chemical reactions. The conformations of the synthesized compounds were studied using mainly solution Proton Nuclear Magnetic Resonance (1H NMR) spectroscopic methods. Two of the synthesized compounds 5, 6, were found to have a partial cone conformation with the third, 4, having the cone conformation. Detailed variable temperature Proton Nuclear Magnetic Resonance studies further confirmed the partialcone conformation for the two products, 5, 6. During the variable temperature nuclear magnetic resonance spectroscopic studies, 6,15,24-tri-tert-butyl-9,18,27-trimethoxy[3.3.3]metacyclophane-2,11,20-triol was found to have a coalescence temperature of about 0?C.
基金supported by the National Natural Science Foundation of China(21165006)the Fund of the International Cooperation Projects of Guizhou Province(20137002)the"Chun-Hui"Fund of Chinese Ministry of Education(Z2011033 and Z2012053)
文摘A new thiacalix[4]arene phenothiazine derivative(2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescence emission, with a large Stokes shift(λex/em = 357 nm/505 nm, Δλ = 148 nm), which helps to avoid interference in excitation and emission. For the metal ions tested, the fluorescence of Compound 2 was quenched only by Fe3+ and Cr3+ ions. Evidence for the hydrolysis reaction promoted by the metal ions is given by X-ray crystallography, mass spectra(MS), infrared(IR) spectra, and fluorescence spectroscopy data.
基金the support of National Natural Science Foundation of China(No.21162003)the International Collaboration Project of Guizhou Province(No.[2011]7003)the Natural Science Foundation of Guizhou Province(No.[2008]75).
文摘The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) inaqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronicand geometric structure of substrate. In the cases of o-benzenedimethanol (1a) and m-benzenedimethanol (1b), theIBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation ofthe catalytic activity of Q[8] when p-benzenedimethanol (1c) is subjected to the IBX oxidation. The additionamount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidationmuch more. The investigation of host-guest interactions by isothermal titration calorimetry implies the supramolecularcatalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril.