An 2-anfinopyddyl-bddged calix[6]arene on the upper rim fixed in cone conformation （3） was successfully synthesized and its highly selective recognition towards fluoride ion was proved by fluorescent and 1H NMR titr...An 2-anfinopyddyl-bddged calix[6]arene on the upper rim fixed in cone conformation （3） was successfully synthesized and its highly selective recognition towards fluoride ion was proved by fluorescent and 1H NMR titration experiments.展开更多
Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed ...Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed to reveal the origin of the interaction.The intermolecular interaction energy was evaluated with basis set superposition error correction（BSSE） and zero point energy correction（ZPEC）.The B3LYP/6-31G（d） calculations on the five complexes have shown that the greatest interaction（–13.98 kJ/mol） is found in the complex between HMX and hexa-aza-calix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine.The results have indicated that intermolecular interaction energies of aza-calix[6]arenes with substituted group are stronger than those without substituted group,and those with amido are greater than with nitryl.Thus,hexa-azacalix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine is rather equal to eliminate HMX from explosive waste water.展开更多
An inclusion complex between p-tert-butylcalixarene and toluene was prepared. It crystallized in the monoclinic system with space group P 2 1/ n , a =1.734 7(2) nm, b =1.903 2(2) nm, c =1.972 9(2) ...An inclusion complex between p-tert-butylcalixarene and toluene was prepared. It crystallized in the monoclinic system with space group P 2 1/ n , a =1.734 7(2) nm, b =1.903 2(2) nm, c =1.972 9(2) nm , β =94.74(1)°, V =6.491 2(14) nm 3, Z =4. The toluene molecule was included in the macrocycle cavity. The calixanene is of a pinched cone conformation.展开更多
Three full-substituted calix[6]arenes containing the picolinamide groups were synmesized and characterized by IR, ^1HNMR and MS, after series reactions, including lower rim etherification, upper rim ipso-nitration, re...Three full-substituted calix[6]arenes containing the picolinamide groups were synmesized and characterized by IR, ^1HNMR and MS, after series reactions, including lower rim etherification, upper rim ipso-nitration, reduction, amidation.展开更多
A bisphosphate-bridged tetrahomodioxacalix[6]arene with a C2v symmetry at the ambient temperature was obtained by the reaction of tetrahomodioxacalix[6]arene with POCl3.
By 1,4-bridging of p-tert-butylcalix [6] arene with 2,6-bis (bromomethyl)-4-methyl- anisole, a new type of bis-calix [5] arene analogue was obtained in high yield..
An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of ...An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about ?0.60 V and ?0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb2+ 3.0×10?8–8.0×10?6 mol·L?1 and with that of Cd2+ 6.0×10?8–1.0×10?5 mol ·L?1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10?9 mol·L?1 and 2.0×10?8 mol·L?1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Key words lead(II) - cadmium(II) - calix[6]arene - differential pulse stripping voltammetry - chemically modified electrode CLC number O 657.15 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.展开更多
The aim of this work was to study the electrochemical behavior of gold electrode which was modified with p-tert-butylcalix[6]arene membrane and this in the presence of different nickel ions based concentrations in ord...The aim of this work was to study the electrochemical behavior of gold electrode which was modified with p-tert-butylcalix[6]arene membrane and this in the presence of different nickel ions based concentrations in order to form a nickel electrochemical sensor. For that, impedance-spec- troscopy characteristics have been investigated. The obtained results were then modeled by appropriate equivalent circuit aiming at elucidating the electrical properties of the modified gold transducer. A correlation between the present impedimetric results and previous potentiometric ones was achieved traducing then a fast ionic transfer.展开更多
The synthesis and characterization of the first example of lower-rim-connected double-calix[6]arene are reported, in which a 1,2,4-triply bridged calix[6]arene subunit is connected to a calix[6]arene subunit via a pol...The synthesis and characterization of the first example of lower-rim-connected double-calix[6]arene are reported, in which a 1,2,4-triply bridged calix[6]arene subunit is connected to a calix[6]arene subunit via a polyether chain.展开更多
基金the National Natural Science Foundation of China(No.20502008)the State Science Foundation of China(No.05300152)the Science Foundation of Tianjin Medical University(No.2006x9d2) for financial support
文摘An 2-anfinopyddyl-bddged calix[6]arene on the upper rim fixed in cone conformation （3） was successfully synthesized and its highly selective recognition towards fluoride ion was proved by fluorescent and 1H NMR titration experiments.
文摘Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed to reveal the origin of the interaction.The intermolecular interaction energy was evaluated with basis set superposition error correction（BSSE） and zero point energy correction（ZPEC）.The B3LYP/6-31G（d） calculations on the five complexes have shown that the greatest interaction（–13.98 kJ/mol） is found in the complex between HMX and hexa-aza-calix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine.The results have indicated that intermolecular interaction energies of aza-calix[6]arenes with substituted group are stronger than those without substituted group,and those with amido are greater than with nitryl.Thus,hexa-azacalix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine is rather equal to eliminate HMX from explosive waste water.
文摘An inclusion complex between p-tert-butylcalixarene and toluene was prepared. It crystallized in the monoclinic system with space group P 2 1/ n , a =1.734 7(2) nm, b =1.903 2(2) nm, c =1.972 9(2) nm , β =94.74(1)°, V =6.491 2(14) nm 3, Z =4. The toluene molecule was included in the macrocycle cavity. The calixanene is of a pinched cone conformation.
基金Thanks for the support of the National Natural Science Foundation of China （No.20376059）.
文摘Three full-substituted calix[6]arenes containing the picolinamide groups were synmesized and characterized by IR, ^1HNMR and MS, after series reactions, including lower rim etherification, upper rim ipso-nitration, reduction, amidation.
文摘A bisphosphate-bridged tetrahomodioxacalix[6]arene with a C2v symmetry at the ambient temperature was obtained by the reaction of tetrahomodioxacalix[6]arene with POCl3.
基金Financial supports from the National Natural Science Foundation of China and Hubei province are gratefully acknowledged.
文摘By 1,4-bridging of p-tert-butylcalix [6] arene with 2,6-bis (bromomethyl)-4-methyl- anisole, a new type of bis-calix [5] arene analogue was obtained in high yield..
文摘An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about ?0.60 V and ?0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb2+ 3.0×10?8–8.0×10?6 mol·L?1 and with that of Cd2+ 6.0×10?8–1.0×10?5 mol ·L?1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10?9 mol·L?1 and 2.0×10?8 mol·L?1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Key words lead(II) - cadmium(II) - calix[6]arene - differential pulse stripping voltammetry - chemically modified electrode CLC number O 657.15 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.
文摘The aim of this work was to study the electrochemical behavior of gold electrode which was modified with p-tert-butylcalix[6]arene membrane and this in the presence of different nickel ions based concentrations in order to form a nickel electrochemical sensor. For that, impedance-spec- troscopy characteristics have been investigated. The obtained results were then modeled by appropriate equivalent circuit aiming at elucidating the electrical properties of the modified gold transducer. A correlation between the present impedimetric results and previous potentiometric ones was achieved traducing then a fast ionic transfer.
文摘The synthesis and characterization of the first example of lower-rim-connected double-calix[6]arene are reported, in which a 1,2,4-triply bridged calix[6]arene subunit is connected to a calix[6]arene subunit via a polyether chain.
