共查询到20条相似文献,搜索用时 31 毫秒
1.
Jerry L. Atwood Leonard J. Barbour Colin L. Raston Ida B. N. Sudria 《Angewandte Chemie (International ed. in English)》1998,37(7):981-983
Isostructural species are found in the solid state for the supramolecular 1:2 complexes of a calix[6]arene molecule and either C60 or C70 (see the structure of the [(calix[6]arene)(C60)2] complex on the right). The calixarene assumes a double-cone conformation, and the overall structure is a result of the complementarity of the building blocks with respect to size and form—in other words, the shallow calixarene cavity and the fullerene surface have similar curvatures. 相似文献
2.
Yuanyin Chen Shuling Gong 《Journal of inclusion phenomena and macrocyclic chemistry》2003,45(3-4):165-184
Bridging including capping of calix[6]arene is not only an importantroute to synthesize new host molecules, but also an efficient route to reduce the mobility of conformationof calix[6]arene. This article reviews the syntheses, conformations and complexation behavior of this kindof host molecules. 相似文献
3.
New Calix[4]arene‐Cored Peripherally Functionalized Dendrimers: Synthesis and Conformational Characteristics 下载免费PDF全文
Georgios Paraskevopoulos Dimitrios Alivertis Vassiliki Theodorou Konstantinos Skobridis 《Helvetica chimica acta》2015,98(5):593-603
New calixarene‐based dendrimers, containing calix[4]arene as the core and different generations of Fréchet‐type poly(benzyl ether) dendrons as building blocks, which possess either Br‐atoms or COOtBu groups at their surface were synthesized and presented herein for the first time. The new calix[4]arene‐cored dendritic macromolecules were fully characterized and found to prefer strictly the cone conformation. 相似文献
4.
Marcus S. Brody Christoph A. Schalley Dmitry M. Rudkevich Julius Rebek Jr. 《Angewandte Chemie (International ed. in English)》1999,38(11):1640-1644
There is more than one way to assemble the two halves of a tethered, urea-substituted calix[4]arene dimer (shown schematically): formation of unimolecular capsules (far left), dimers, or oligomers. By combination of NMR spectroscopy and electrospray mass spectrometry, a hexamethylene spacer was shown to be exactly right to permit the preferential formation of a unimolecular capsule under inclusion of solvent or other guest molecules. 相似文献
5.
Yoshito Tobe Naoto Utsumi Atsushi Nagano Koichiro Naemura 《Angewandte Chemie (International ed. in English)》1998,37(9):1285-1287
Intriguing association behavior in solution is exhibited by the rigid macrocycle 1 . For instance, it reacts with organic cations to give ternary complexes of the composition ( 1 ⋅cation)⋅ 1 , and with analogous macrocycles without cyano groups it forms heteroaggregates. R=CO2C8H17. 相似文献
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7.
Xiao‐Hong Tian Chuan‐Feng Chen Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(27):8072-8079
Two pairs of novel triptycene‐derived calix[6]arenes 4 a , b and 5 a , b have been efficiently synthesized through both one‐pot and two‐step fragment‐coupling strategies starting from 2,7‐bis(hydroxymethyl)‐1,8‐dimethoxytriptycene 1 . Subsequent demethylation of 4 a , b and 5 a , b with BBr3 in dry dichloromethane gave the macrocyclic compounds 6 a , b and 7 a , b . Treatment of either 4 a or 6 a with AlCl3 resulted in the same debutylated product 8 , while 9 was similarly obtained from either 5 a or 7 a . Structural studies revealed that all of the macrocycles have well‐defined structures with fixed conformations both in solution and in the solid state owing to the introduction of the triptycene moiety with a rigid three‐dimensional (3D) structure, making them very different from their classical calix[6]arene counterparts. As a consequence, it was found that all of these the triptycene‐derived calix[6]arenes could encapsulate small neutral molecules in their cavities in the solid state. Moreover, it was also found that the macrocycles 4 b and 5 b showed highly efficient complexation abilities toward fullerenes C60 and C70, forming 1:1 complexes with association constants ranging from (5.22±0.20)×104 to (8.68±0.30)×104 M ?1. 相似文献
8.
Julius Rebek 《Angewandte Chemie (International ed. in English)》1990,29(3):245-255
How structures fit together is the principal domain of molecular recognition, and current studies are evolving from the host–guest chemistry of ions to interactions between two molecules. Recent advances in the synthesis of sizable concave molecules, especially those featuring convergent functional groups, make it possible to bind smaller convex structures with considerable selectivity. One result is that hydrogen bonding can be addressed in model systems. The present review emphasizes the use of cleftlike structures as a means of probing the forces involved in nucleic acid recognition. The application of such molecules to the catalysis of chemical reactions, particularly those involved in self-replicating systems, is also described. Some implications for future pharmaceutical agents are suggested as a result of access to synthetic receptors for biologically relevant targets. 相似文献
9.
Oleg V. Surov Nugzar Zh. Mamardashvili Gennadiy P. Shaposhnikov Oskar I. Koifman 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):329-335
The inclusion of small neutral organic guests (C6H14, CH2Cl2, CH3OH) by calix[4]arene receptors was found by 1H NMR spectroscopy and microanalysis. The studied calix[4]arenes can form stable intramolecular complexes with solvent molecules
which keep the stoichiometric composition without changing under conditions of the sublimation experiment. The saturated vapour
pressures of calix[4]arenes and complexes of calix[4]arenes with solvent molecules were determinated for the first time by
the Knudsen’s effusion method in the wide temperature range. The changing of standard thermodynamic parameters of complexation
by transfer process from condensed state to vapour phase was estimated. It was shown that the large flexibility of the calixarene
ligand structure corresponds to a strongly negative entropic contribution as well as negative enthalpy term to the Gibbs energy
of formation of host–guest complexes in the gas phase. 相似文献
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11.
Jean-Alexandre Richard Marc Pamart Nicolas Hucher Ivan Jabin 《Tetrahedron letters》2008,49(24):3848-3852
The straightforward synthesis of a Cs symmetrical calix[6]arene possessing carboxylic acid groups as well as an ammonium arm is described. This calixarene can encapsulate ammonium ions through a highly selective recognition process thanks to the presence of an internal ion-paired cap that preorganizes the cavity and constitutes an efficient binding site. 相似文献
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Valentyn Rudzevich Dr. Oleg Kasyan Dr. Andriy Drapailo Dr. Michael Bolte Dr. Dieter Schollmeyer Dr. Volker Böhmer Dr. 《化学:亚洲杂志》2010,5(6):1347-1355
Thiacalix[4]arene 2 , calix[4]arene 3 a and its tetraether fixed in the cone conformation 3 b form homo‐ and heterodimeric capsules in apolar solvents, which are held together by a seam of NH???O=P hydrogen bonds between carbamoylmethyl phospine oxide functions attached to their wide rim. Their internal volume of ~370 Å3 requires the inclusion of a suitable guest. Although neutral molecules such as adamantane (derivatives) or tetraethylammonium cations form kinetically stable complexes (1H‐ and 31P‐time scale), the included solvent is rapidly exchanged. The internal mobility of the included tetraethylammonium cation is distinctly higher (ΔG=42.5 and 49.7 kJ mol?1 for 3 a and 3 b ) than that for similar capsules of tetraurea calix[4]arenes 1 . Mixtures of 1 with 2 , 3 a , or 3 b contain only the two homodimers but the heterodimerization occurs with the tetraloop tetraurea 6 , which cannot form homodimers. Two dimers with cationic guests ( 2? (C5H5)2Co+ ?2 and 3 a? Et3NH+ ? H2O ?3 a ) were confirmed by single‐crystal X‐ray analysis. 相似文献
14.
Tommaso Mecca 《Tetrahedron》2007,63(44):10764-10767
Three new calix[4]arene-based receptors as potential antimicrobial agents have been synthesized. Their recognition ability towards lipopolysaccharides of Gram-negative bacteria has been studied by NMR and UV titrations. 相似文献
15.
Alex Inthasot Emilio Brunetti Dr. Manuel Lejeune Dr. Nicolas Menard Prof. Dr. Thierry Prangé Dr. Luca Fusaro Dr. Gilles Bruylants Prof. Dr. Olivia Reinaud Prof. Dr. Michel Luhmer Prof. Dr. Ivan Jabin Dr. Benoit Colasson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4855-4862
The Huisgen thermal reaction between an organic azide and an acetylene was employed for the selective monofunctionalization of a X6‐azacryptand ligand bearing a tren coordinating unit [X6 stands for calix[6]arene and tren for tris(2‐aminoethyl)amine]. Supramolecular assistance, originating from the formation of a host–guest inclusion complex between the reactants, greatly accelerates the reaction while self‐inhibition affords a remarkable selectivity. The new ligand possesses a single amino‐leg appended at the large rim of the calixarene core and the corresponding Zn2+ complex was characterized both in solution and in the solid state. The coordination of Zn2+ not only involves the tren cap but also the introverted amino‐leg, which locks the metal ion in the cavity. Compared with the parent ligand deprived of the amino‐leg, the affinity of the new monofunctionalized X6tren ligand 6 for Zn2+ is found to have a 10‐fold increase in DMSO, which is a very competitive solvent, and with an enhancement of at least three orders of magnitude in CDCl3/CD3OD (1:1, v/v). In strong contrast with the fast binding kinetics, decoordination of Zn2+ as well as transmetallation appeared to be very slow processes. The monofunctionalized X6tren ligand 6 fully protects the metal ion from the external medium thanks to the combination of a cavity and a closed coordination sphere, leading to greater thermodynamic and kinetic stabilities. 相似文献
16.
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
17.
Tatsuya Oshima Masahiro Goto Shintaro Furusaki 《Journal of inclusion phenomena and macrocyclic chemistry》2002,43(1-2):77-86
A series of calixarene carboxylic acid derivatives were synthesized for the extraction of amino acids. A calix[6]arene carboxylic acid derivative showed the highest extractability to the target tryptophan ester. The main driving forcefor the complexation was the interaction between the ammonium cation of the aminoacid and the oxygen atoms of the host molecule. Stripping of amino acids was alsoaccomplished by contacting the organic solution with a fresh acidic solution. Basedon slope and Job method analyses, it was confirmed that the calix[6]arene formsa 1 : 1 complex with the amino acid ester. The structure of the complex between the calix[6]arene and the amino acid was investigated by 1H-NMR and CD spectra. The calix[6]arene includes a guest molecule in the cavity, and the inclusion induces the asymmetrization of the host molecule. This host compound functions as a novel recognition tool for amino acids. 相似文献
18.
Yu Chen Prof. Derong Cao Lingyun Wang Minqing He Prof. Lixia Zhou Dieter Schollmeyer Prof. Herbert Meier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7064-7070
The self‐inclusion behavior of monoester copillar[5]arenes depends on the position of the ester group, which causes different guest selectivities. Monoester copillar[5]arenes bearing an acetate chain can form stable self‐inclusion complexes in low‐ and high‐concentration solution and exhibit high guest selectivity. However, a monoester copillar[5]arene bearing a butyrate chain can not form a self‐inclusion complex and exhibits low guest selectivity. Thus, a new class of stable self‐inclusion complexes of copillar[5]arenes was explored to improve the selectivity of molecular recognition. 相似文献
19.
Najah Cheriaa Mouna Mahouachi Amel Ben Othman Lassaad Baklouti Yang Kim Rym Abidi 《Supramolecular chemistry》2013,25(3):265-271
A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers. Replacement of the quadridentate amine by a trithia-ether-triamine-mono-ol, ’hyten’, again results in acylation of the amino groups, but with the generation of a central cavity with different complexing properties. A new family of hyperbranched molecules and dendrimers has been constructed from a diamide–dicalix derivative prepared from monocarbomethoxymethyl p-tert-butyl calix[4]arene and tris(2-aminoethyl)amine (‘tren’) via amide-formation reactions. The selective 1,3-di-O-functionalization of p-tert-butyl calix[4]arene moieties allows the synthesis of first- (G1) and second-generation (G2) calix-dendrimers 相似文献
20.
Dr. Raquel Andreu Dr. Santiago Franco Prof. Javier Garín Judith Romero Dr. Belén Villacampa Dr. María Jesús Blesa Dr. Jesús Orduna 《Chemphyschem》2012,13(13):3204-3209
Multichromophoric calix[4]arenes with two or four disperse red one (DR1) moieties linked to the lower rim have been synthesized. The second‐order nonlinear optical activity was measured by using the electric‐field‐induced second‐harmonic generation technique and there was a nearly linear increase of the μβ value with the number of chromophores in the molecule without affecting the charge‐transfer absorption wavelength. The effect that the number of DR1 units plays on the hyperpolarizability, the dipole moment, and the absorption maxima has been also studied by using quantum chemical calculations. It was found that it was necessary to synthesize multichromophores with distant chromophores to obtain large nonlinear optical responses. 相似文献