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1.
Hisatoshi Konishi Shun Hashimoto Terunobu Sakakibara Shingo Matsubara Yusuke Yasukawa Osamu Morikawa Kazuhiro Kobayashi 《Tetrahedron letters》2009,50(6):620-10412
Tetranitroazacalix[4]arenes have been synthesized by the nucleophilic aromatic substitution of 1,5-difluoro-2,4-dinitrobenzene with 1,3-diaminobenzenes. An X-ray crystal structure analysis revealed that the azacalixarenes adopt a non-symmetrical 1,3-alternate conformation, and the dinitrobenzene rings strongly conjugate with the bridging nitrogen atoms. In the 1H NMR spectrum (CDCl3, 30 °C), the tetraisopropyl derivative 3b displays a pair of diastereotopic methyl signals of the isopropyl groups in agreement with the frozen 1,3-alternate conformation on the NMR time scale. The free energy of activation () for the macrocyclic inversion was determined to be 87.5 kJ mol−1 by temperature-dependent NMR spectroscopy. 相似文献
2.
Francesco Troisi 《Tetrahedron letters》2009,50(36):5113-1230
Pyrrolamidocalix[4]arenes 1-4, members of a new class of anion receptors bearing pyrrolic units at the upper rim of calix[4]arene macrocycle, have been readily synthesized in good yields. Derivatives 1 and 3, with unsubstituted pyrrole units, show a good selectivity for over F− and AcO−, while the presence of electron-withdrawing NO2 substituents in 2 and 4 inverts the selectivity favoring more basic AcO− and F−. In addition, it is demonstrated that the flexibility of calix[4]arene skeleton, present in 1 but absent in 3, is very important in the fitting process that leads the amidopyrrole moieties to wrap the tetrahedral guest. 相似文献
3.
Dvoráková H Lang J Vlach J Sýkora J Cajan M Himl M Pojarová M Stibor I Lhoták P 《The Journal of organic chemistry》2007,72(19):7157-7166
NMR spectroscopy, X-ray diffraction analysis, and quantum chemical calculations were used for conformational behavior study of partially alkylated thiacalix[4]arenes bearing methyl (1), ethyl (2), or propyl (3) groups at the lower rim. The conformational properties are governed by two basic effects: (i) stabilization by intramolecular hydrogen bonds, and (ii) sterical requirements of the alkoxy groups at the lower rim. While the monosubstituted derivatives 1a and 3a adopt the cone conformation in solution, distally disubstituted compounds 1b, 1'b, 2b, 2'b, 3b, and 3'b exhibit several interesting conformational features. They prefer pinched cone conformation in solution, and, except for 3'b, they form also 1,2-alternate conformation, which is flexible and undergoes rather fast transition between two identical structures. The crystal structures of the compounds 1b, 2b, 2'b, and 3b revealed yet quite rare 1,2-alternate conformation forming molecular channels held together by pi-pi interactions. Different channels-with hexagonal symmetry, 0.26 nm wide-are formed in the crystal structure of the pinched cone conformation of 3b. An uncommon hydrogen bonding pattern was found in dimethoxy and dipropoxy derivatives 1'b and 3'b that adopt distorted cone conformations in crystal. Trialkoxy-substituted compounds 1c and 3c adopt the partial cone conformation in solution. A higher mobility of methyl derivative 1c enables also existence of the cone conformer. 相似文献
4.
Özlem Özen Karakuş Hasalettin Deligöz 《Journal of inclusion phenomena and macrocyclic chemistry》2008,61(3-4):289-296
The synthesis of series of chromogenic di-substituted azocalix[4]arene derivatives is described. A ketone moiety as a different chelating agent is grafted on the lower rim of p-tert-butylcalix[4]arenes. Eight novel azocalix[4]arenes (1–8) are prepared by linking 2-, 3- and 4-nitroaniline, 4-phenylazoaniline, 3- and 4-chloroaniline or 2- and 4-methylaniline to 25,27-diacetonyloxy-26,28-dihydroxy-11,23-di-(tert-butyl)calix[4]arene through a diazo-coupling reaction, and characterized by UV–Vis, FT-IR and 1H-NMR spectroscopic techniques and elemental analysis, consecutively. The absorption spectra of the di-substituted azocalix[4]arenes are discussed, according to effect of varying pH and solvent upon the absorption ability of azocalix[4]arenes. The colors of these azocalix[4]arenes are compared with respect to nature of their aromatic rings and substituents there in. Concentration effects on the visible absorption maxima of these compounds are also reported. 相似文献
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6.
Mine Sulak Ak Hasalettin Deligöz 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):115-123
Four new azocalix[4]arenes {5,11,17,23-tetrakis[(2-hydroxy-5-tert-butylphenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (1), 5,11,17,23-tetrakis[(2-hydroxy-5-nitro phenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (2), 5,11,17,23-tetrakis[(2-amino-5-carboxylphenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (3) and 5,11,17,23-tetrakis[(1-amino-2-hydroxy-4-sulfonicacidnapthylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (4)} have been synthesized from p-tert-butylphenol, p-nitrophenol, p-aminobenzoic acid and 1-amino-2-hydroxy-4-sulphonic acid by diazo coupling reaction with p-aminocalix[4]arene. The resulting ligands (1–4) were treated with three transition metal salts (e.g., CuCl2·2H2O, NiCl2·6H2O or CoCl2·6H2O). Cu(II), Ni(II) and Co(II) complexes of the azocalix[4]arene derivatives were obtained and characterized by UV-vis, IR,
1H-NMR spectroscopic techniques and elemental analysis. All the complexes have a metal:ligand ratio of 2:1. The Cu(II) and
Ni(II) complexes of azocalix[4]arenes are square-planar, while the Co(II) complexes of azocalix[4]arenes are octahedral with
water molecules as axial ligands. The solvent extraction of various transition metal cations from the aqueous phase to the
organic phase was carried out by using azocalix[4]arenes (1–4). It was found that, azocalix[4]arenes 1, 2 and 3 examined selectivity for transition metal cations such as Ag+, Hg+ and Hg2+. In addition, the thermal stability of metal:azocalix[4]arene complexes were also reported.
Dedicated to Prof. Dr. Mustafa Yılmaz on the occasion of his 50th birthday 相似文献
7.
Kwanghyun No Jong Seung Kim Seyoung Kim Duong Tuan Quang In-Chul Hwang Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):353-360
A series of tetrahomodiazacalix[4]arenes (1–8) with different substituents (or substituted) at the upper rim and/or N-side arm has been synthesized with acceptable yields. The compounds were characterized by elemental analysis, IR, MS and
NMR methods. In particular, 5 was shown by X-ray crystallography to adopt the cone conformation in the solid state. Two-phase picrate extraction showed
that 2 and 6, bearing N-2-picolyl arms, are the best extractants. Of the cations tested, Ag(I) is the best extracted by almost all ligands and the
extraction efficiency follows the order 2-picolyl > 3-picolyl > 4-picolyl. 相似文献
8.
Boyko V. I. Rozhenko A. B. Pirozhenko V. V. Shishkina S. V. Shishkin O. V. Kalchenko V. I. 《Structural chemistry》2016,27(1):261-272
Structural Chemistry - The facile method of generating internal chirality into the calixarene with two hydroxy groups at the lower rim via an attached chiral substituent has been proposed. The... 相似文献
9.
The facile preparation of N(H)-bridged azacalix[4]arenes has been achieved by stepwise nucleophilic aromatic substitutions assisted by hydrogen bonding interactions. The synthesis is uncatalyzed and affords previously unknown tetranitroazacalix[4]arenes. 相似文献
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11.
Three acetonitrile solvates of tetramethoxycalix[4]arenes equally substituted on opposite methylene bridges are described with respect to their conformation and packing behaviour. All of the host molecules adopt a 1,2-alternate conformation, their packing architecture seems to be affected by the spatial demand of the bridge substituents only. This results in the synthetically implemented fine-tuning of the molecular arrangement. The engineering of the relevant packing motif, the “synthon” may be discussed most appropriate by the term “synthon engineering” following the expression of crystal engineering. 相似文献
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13.
p-Perfluoroalkylealix[4]arenes were prepared readily from the reaction of calix-[4]arene with perfluoroalkyl iodides in the presence of sodium dithionite or sodium hydroxy-methanesulfinate under mild conditions,These fluorine-containing calixarenes showed bettersolubilities in common organic solvents as compared to their nonperfluoroalkylation analogand formed inclusion complexes with many neutral molecules as well as fluorocarbons. 相似文献
14.
X-ray diffraction, thermogravimetric, and adsorption measurements were applied to study the thermal decomposition of the complexes of 25,26,27,28-tetrahydroxycalix[4]arene and 4-tert-butylcalix[4]arene with the solvents resulting in the formation of porous phases. Diffusion of the "guest" (solvent, gas) through the molecular crystal of calixarene-host proceeds via the consecutive formation of a series of thermodynamically unstable porous phases of the "host." Owing to the structural reorganization of calixarene, the transport of the "guest" occurs through the "host" matrix followed by complexation and formation of the thermodynamically stable structure. 相似文献
15.
The acylation of thiacalix[4]arenes with AcCl or Ac2O gave the corresponding lower-rim tetraacetoxy derivatives. In contrast to classical calix[4]arenes, tetraacetylated thiacalix[4]arenes are conformationally mobile in solution and represent a thermodynamic equilibrium of three different conformers at room temperature. As proven by a dynamic 1H NMR study, conformational preferences of acetylated thiacalix[4]arenes considerably depend on the upper-rim substitution. Hence, t-Bu thiacalixarene prefers 1,3-alternate and 1,2-alternate conformations (43% and 38%, respectively), while the upper-rim unsubstituted compound adopts preferably the partial cone conformation (70%). 相似文献
16.
Covalently assembled resorcin[4]arenes and molecular tweezers: a chiral recognition rationale by NMR
Gloria Uccello Barretta Federica Balzano Federica Aiello Francesca Nardelli Alessia Ciogli Andrea Calcaterra 《Supramolecular chemistry》2016,28(7-8):647-655
Chiral diamides and tetramidic resorcin[4]arenes deriving from (R,R)-1,2-diaminocyclohexane and (S,S)-1,2-diphenylethylendiamine, and a valine containing resorcin[4]arene have been compared by NMR in the enantiodiscrimination of mandelic acid. The relevance of cooperation between side arms and external surface of resorcin[4]arene core has been ascertained. 相似文献
17.
Wong MS Xia PF Zhang XL Lo PK Cheng YK Yeung KT Guo X Shuang S 《The Journal of organic chemistry》2005,70(7):2816-2819
[reaction: see text] A facile and efficient protocol for the synthesis of oligophenylene OPP(n)-substituted calix[4]arenes (with n up to 4) via iodo-substituted oligoarylcalix[4]arenes has been developed. The cooperation effect of the proximate fluoroionophores in hexylsulfanyl end-capped OPP(n)-substituted calix[4]arene assemblies leads to metal ion binding enhancement. 相似文献
18.
Paul D. Beer Anthony D. Keefe 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(4):499-504
The condensation of 1,1-bis(chlorocarbonyl)metallocenes andp-tert-butylcalix[4]arene in toluene leads to novel metallocene calix[4]arenes in which the metallocene subunit bridges the opposite hydroxy groups of the parent calixarene.Presented at the Fourth International Symposium on Inclusion Phenomena and the Third International Symposium on cyclodextrins, Lancaster, U.K., 20–25 July 1986. 相似文献
19.
New macrocyclic tetrathiacalix[4]arenes have been synthesized by incorporating arylazo-, thiazoleazo- and β-naphthylazo- units in the tetrathiacalix[4]arene molecular architecture through diazotization and coupling reactions. The new compounds have been characterized by 1H NMR, 13C NMR and FAB-MS spectroscopic analysis. X-ray crystallography for one of the new dyes (4a) reveals that the compound is present in the cone conformation. The synthesized macrocycles have been examined for their binding with alkali (Li+, Na+, K+, Cs+ and Rb+), alkaline earth (Ca2+, Mg2+ and Ba2+) and transition metal cations (Cr3+, Fe2+, Co2+, Ni2+, Cu2+, Hg+, Hg2+, Pd2+ and Pt2+) by UV-visible spectroscopy to reveal selective bathochromic shifts for heavier alkali metal ions (cesium and rubidium) and palladium in a 1:1 and 2:1 stoichiometry respectively. The study has a significant bearing on the development of useful ionic filters and sensor materials. 相似文献
20.
Bingbing Shi Zhengtao Li Yuezhou Liu Liqing Shangguan Huangtianzhi Zhu Huaqiang Ju Feihe Huang 《Tetrahedron letters》2018,59(38):3477-3480
Here we report the design and syntheses of two new triptycene-based rigid acyclic C-shaped hosts, clip[5]arenes C[5]OH and C[5]ME, and the strong host–guest complexation between C[5]OH and an electron-poor bipyridinium salt, paraquat G. The Ka value for the host–guest complex C[5]OH???G was calculated to be (1.09?±?0.36)??×??105?M?1 in acetone by using a non-linear curve-fitting method based on the UV–vis absorption titration experiments. Furthermore, based on this new host–guest recognition motif, a novel pseudopolyrotaxane-like supramolecular structure was constructed with C[5]OH threaded on polyviologen polymer VP-10. 相似文献