Synthesis, Structure, and [60]Fullerene Complexation Properties of Azacalix[<i>m</i>]arene[<i>n</i>]pyridines

Wang, Mei‐Xiang; Zhang, Xiaohang; Zheng, Qiang

doi:10.1002/anie.200351975

Cited by 260 publications

(92 citation statements)

References 66 publications

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“…[20] The preparation of derivatives 10 a and 10 b (Figure 4) is remarkably straightforward; they are both obtained in three steps starting from 1,3-diaminobenzene and 2,6-dibromopyridine. [21] Unlike 10 b, the addition of 10 a to a C 60 solution does not lead to any color change, thus suggesting that no interaction takes place with the smaller macrocycle 10 a, as was confirmed by UV/Vis and fluorescence titrations. These studies demonstrate that 10 b forms 1:1 complexes with both C 60 and C 70 , and the authors report binding constants of log K sv = 4.8 and 5.1 in toluene at 298 K for C 60 and C 70 , respectively, although they neglect the effect of possible dynamic quenching.…”

Section: Aromatic Heterocycles For Fullerene Recognitionmentioning

confidence: 56%

Wraparound Hosts for Fullerenes: Tailored Macrocycles and Cages

2011

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Custom-made macrocyclic receptors for fullerenes are proving a valuable alternative to achieve the affinity and selectivity required to meet challenges such as the selective extraction of higher fullerenes, their chiral resolution, or the self-assembly of functional molecular materials. In this Minireview, we highlight some of the important breakthroughs that this class of fullerene hosts has already produced.

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Section: Aromatic Heterocycles For Fullerene Recognitionmentioning

confidence: 56%

Wraparound Hosts for Fullerenes: Tailored Macrocycles and Cages

2011

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“…In this context, host molecules composed of triarylamines should exhibit high affinities for fullerenes in comparison with the corresponding phenol-based receptors. Actually, the K SV values of a dendrimer 19 [36], azacalix [3]arene [3]pyridine 20 [37], and azacalix[n]pyridine 21 (n ¼ 4-9) [38] are considerably high (K SV for 19ÁC 60 ¼ 180000 AE 80000 Â 10 5 M À1 , K SV for 20ÁC 60 ¼ 70680 AE 2060 M À1 , and K SV for 20ÁC 70 ¼ 136620 AE 3770 M À1 ) (Figure 3.9). The participation of additional attractive CT interaction should play an important role in the complexation.…”

Section: Modified Traditional Host Moleculesmentioning

confidence: 99%

Receptors for Pristine Fullerenes Based on Concave–Convex π–πInteractions

Kawase

2012

Supramolecular Chemistry of Fullerenes and Carbon Nanotubes

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In 1990, Kr€ atchmer and coworkers reported the extraction of fullerenes (C 60 and C 70 ) from carbon soot using aromatic solvents (Figure 3.1) [1]. After this discovery, receptor molecules for fullerenes have been extensively studied for separation and purification of fullerenes. Supramlecular chemists have found that traditional host molecules composed of electron-rich aromatic rings such as calix[n]arenes 1-4, oxacalix[3]arenes 5, and cyclotriveratrylenes (CTV) 6 ( Figure 3.2) can be employed for the purpose. The crystallographic analyses of these complexes with C 60 clearly indicated the importance of the p-p interactions between the convex p surface of C 60 and the concave p surface of the traditional host molecules. On the other hand, except a few examples, the traditional hosts bound fullerenes only in solid state. In order to bind with fullerenes more tightly, two strategies have been presented to construct the well preorganized p cavity so far. First, electron-rich aromatic units are introduced to the host molecule as appendants (Figure 3.2a). Second, two host molecules are linked by appropriate tether(s) to form a dimeric structure with a creft-, ring-, or ball-shaped cavity (Figure 3.2b). The binding abilities of the modified receptors fairly increased in comparison with those of simple traditional hosts. On the other hand, new receptors based on curved conjugated systems such as corannulene 7, extended TTF (exTTF) 8, and carbon nanorings (Figure 3.3) have been developed recently. These compounds possess a concave p surface matching to the convex surface of C 60 . Cyclic [6]paraphenyleneacetylene ([6]CPPA) 9 and the related compounds have smooth belt-shaped structure similar to a cut piece of carbon nanotube, and thus may be termed carbon nanorings. These receptors form stable inclusion complexes with fullerenes both in solution and in the solid state, and are good model compounds to explore the nature of the concave-convex p-p interactions. This chapter discusses the fullerene receptors bearing a cavity surrounded by p-orbitals, the so-called p cavity, the concept of molecular designs, and the nature of p-p interactions. The survey of the fullerene receptors should provide an insight into the supramolecular properties of curved conjugated systems. Although the receptor Supramolecular Chemistry of Fullerenes and Carbon Nanotubes, First Edition. Edited by Nazario Martin and Jean-Francois Nierengarten.

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“…[7] While the diversity is still limited relative to those of carbon-and sulfur-bridged calixarenes, intriguing complexation properties based on the introduction of nitrogen atoms as the bridging units have thus far been disclosed. [8][9][10] For instance, Wang reported that azacalix [m]arene[n]pyridines exhibited much greater complexation ability for fullerenes C 60 and C 70 , relative to those of other mono-macrocyclic receptors reported to date.…”

Section: Introductionmentioning

confidence: 99%

Azacalix[6]arene Hexamethyl Ether: Synthesis, Structure, and Selective Uptake of Carbon Dioxide in the Solid State

Tsue

Ishibashi

Tokita

et al. 2008

Chemistry A European J

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To investigate dynamic solid-state complexation hitherto unexplored in nitrogen-bridged calixarene analogues, azacalix[6]arene hexamethyl ether has been prepared in three steps by applying a 5+1 fragment-coupling approach by using a Buchwald- Hartwig aryl amination reaction with the aid of our previously devised temporal N-silylation protocol. X-ray crystallographic analysis and NMR spectroscopic measurements have revealed that the azacalix[6]arene is well endowed with hydrogen-bonding ability, by which both the molecular and crystal structures are controlled. The azacalix[6]arene is conformationally flexible in solution on the NMR time scale, whereas it adopts a definite 1,2,3-alternate conformation with S2 symmetry in the solid state as a result of intramolecular bifurcated hydrogen-bonding interactions. In the crystal, molecules of the azacalix[6]arene are mutually interacted by intermolecular hydrogen bonds to establish one-dimensional hexane-filled nanochannel crystal architecture. Although the single crystal was broken after desolvation, the resultant polycrystalline powder material was capable of selectively adsorbing CO2 among the four main gaseous components of the atmosphere. In contrast, carbocyclic p-tert-butylcalix[6]arene hexamethyl ether, the crystal structure of which was also elucidated for the first time in the present study, gave rise to almost no uptake of CO2. Additional solid-gas adsorption experiments for another three gases, such as N2, O2, and Ar, suggested that quadrupole/induced-dipole interactions and/or hydrogen-bonding interactions played an important role in permitting the observed selective uptake of CO2 by this new azacalix[6]arene in the solid state.

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Synthesis, Structure, and [60]Fullerene Complexation Properties of Azacalix[m]arene[n]pyridines

Cited by 260 publications

References 66 publications

Wraparound Hosts for Fullerenes: Tailored Macrocycles and Cages

Wraparound Hosts for Fullerenes: Tailored Macrocycles and Cages

Receptors for Pristine Fullerenes Based on Concave–Convex π–πInteractions

Azacalix[6]arene Hexamethyl Ether: Synthesis, Structure, and Selective Uptake of Carbon Dioxide in the Solid State

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