A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the ...A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the modified procedure, the yield of 5-bromo-11, 23-di-tert-butyl-17-methyl-25, 26, 27, 28-tetrahydroxycalix[4]arene from cyclic condensation of 2, 6-bis(2’-hydroxy-5’-tert-butyl-benzyl)-4-cresol and 2, 6-bis (bromomethyl)-4-bromophenol in the presence of TiCl4 was improved from less than 20％ to 40％, and the reaction time was reduced from several days to ten hours.展开更多
Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and ...Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.展开更多
The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21...The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21.2721（4）A,β= 97.153（1）°, V = 4261.23（14）A^3, Z = 4, Mr = 914.65, F（000） = 1904, Dc = 1.426 g/cm^3,μ = 0.336, the final R = 0.0550 and wR = 0.1647. The compound was structurally characterized by IR and ^1H NMR. The molecules are stacked through C-H...π interactions and intermolecular C-H...O hydrogen bonds.展开更多
Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the...Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the host and the target molecules, such as metal cations and small organic molecules. In particular, the recognition of amino acids is an interesting theme in biomimetic chemistry.展开更多
Two novel （thia）calixarene-based exTTF derivatives（3a and 3b） were prepared by Mitsunobu reactions in toluene using diethyl azodicarboxylate（DEAD） and triphenylphosphine（PPh3） system. The cyclic voltammograms ...Two novel （thia）calixarene-based exTTF derivatives（3a and 3b） were prepared by Mitsunobu reactions in toluene using diethyl azodicarboxylate（DEAD） and triphenylphosphine（PPh3） system. The cyclic voltammograms of compounds 3a and 3b were provided, and two electron-irreversible waves with redox potentials were observed. Meanwhile, the intermolecular electron transfer（ET） properties of both compounds 3a and 3b towards p-chloranil（Q） and C60 were investigated via UV-Vis and fluorescent spectroscopies, respectively. The results indicated that the in- troduced nonoxidable metal ions（Al^3＋, Pb^2＋, Sc^3＋） might promote the intermolecular ET from compounds 3a and 3b towards Q ensembles, whereas the effects of Sc^3＋ were the most impressive. Furthermore, the effects of the same metal ions（Al^3＋, Pb^2＋, Sc^3＋） added for compound 3b were greater than those for compound 3a. Additionally, the pho- toinduced intermolecular ET from compounds 3a and 3b towards C60 was observed.展开更多
文摘A modified [3+1] cyclization procedure for the synthesis of calix [4]arenes was developed by using diglycol dimethyl ether as the solvent in place of dioxane which was generally adopted in previous literature. By the modified procedure, the yield of 5-bromo-11, 23-di-tert-butyl-17-methyl-25, 26, 27, 28-tetrahydroxycalix[4]arene from cyclic condensation of 2, 6-bis(2’-hydroxy-5’-tert-butyl-benzyl)-4-cresol and 2, 6-bis (bromomethyl)-4-bromophenol in the presence of TiCl4 was improved from less than 20％ to 40％, and the reaction time was reduced from several days to ten hours.
文摘Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.
基金the Scientific Research Fund Projects of China West Normal University(No.06B003)the Youth Fund Projects of Sichuan Educational Department(No.2006B039)
文摘The title complex （C50H44C14O8） was synthesized and structurally determined by single-crystal X-ray diffraction method. It crystallizes in monoclinic, space group P21/n with a = 19.7768（4）, b =10.2085（2）, c = 21.2721（4）A,β= 97.153（1）°, V = 4261.23（14）A^3, Z = 4, Mr = 914.65, F（000） = 1904, Dc = 1.426 g/cm^3,μ = 0.336, the final R = 0.0550 and wR = 0.1647. The compound was structurally characterized by IR and ^1H NMR. The molecules are stacked through C-H...π interactions and intermolecular C-H...O hydrogen bonds.
基金Supported by the National Natural Science Foundation of China(No. 20402002) Natural Science Foundation of FujianProvince, China(Nos. E0220002 and 2006J0155).
文摘Introduction Calixarenes are one of the most important supra- molecular building blocks, which can be modified by introducing different functional and/or structural groups to create a specific interaction between the host and the target molecules, such as metal cations and small organic molecules. In particular, the recognition of amino acids is an interesting theme in biomimetic chemistry.
基金Supported by the National Natural Science Foundation of China（Nos.21172105, 20872058）.
文摘Two novel （thia）calixarene-based exTTF derivatives（3a and 3b） were prepared by Mitsunobu reactions in toluene using diethyl azodicarboxylate（DEAD） and triphenylphosphine（PPh3） system. The cyclic voltammograms of compounds 3a and 3b were provided, and two electron-irreversible waves with redox potentials were observed. Meanwhile, the intermolecular electron transfer（ET） properties of both compounds 3a and 3b towards p-chloranil（Q） and C60 were investigated via UV-Vis and fluorescent spectroscopies, respectively. The results indicated that the in- troduced nonoxidable metal ions（Al^3＋, Pb^2＋, Sc^3＋） might promote the intermolecular ET from compounds 3a and 3b towards Q ensembles, whereas the effects of Sc^3＋ were the most impressive. Furthermore, the effects of the same metal ions（Al^3＋, Pb^2＋, Sc^3＋） added for compound 3b were greater than those for compound 3a. Additionally, the pho- toinduced intermolecular ET from compounds 3a and 3b towards C60 was observed.
