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1.
Angew Chem Int Ed Engl ; 58(36): 12705-12710, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31297923

RESUMO

Exploring dynamic bonds and their applications in fabricating dynamic materials has received great attention. A photoinduced [2]rotaxane-based dynamic mechanical bond (DMB) features visible-light-triggered dynamic bonding behavior that is essentially distinguished from conventional dynamic chemical bonds. In this DMB, a photoisomerizable ortho-fluoroazobenzene unit is introduced as a steric-controllable stopper, the visible-light-induced dynamic wagging movement of which enables the photoregulated threading of the macrocycle. This allows reversible in situ de-/reforming of the mechanical bond without involving dynamic chemical linkage. The DMB-cross-linked polymeric gel shows interesting photoinduced degradation behavior upon visible light irradiation. Benefiting from the distinctive dual dynamic nature of reversible bonding behavior and mechanical interlocked structure, this DMB is expected to serve as a new type of dynamic bond that can be applied in designing dynamic soft materials.

2.
Chem Commun (Camb) ; 54(67): 9356-9359, 2018 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30079425

RESUMO

Photochromic [2]rotaxanes with bidirectional photoswitchability were fabricated, whose colored states exhibit remarkable visible-light and thermal stabilities as revealed by systematically spectroscopic investigations.

3.
Chem Asian J ; 13(19): 2818-2823, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-29975456

RESUMO

The development of artificial self-assembling systems with dynamic photo-regulation features in aqueous solutions has drawn great attention owing to the potential applications in fabricating elaborate biological materials. Here we demonstrate the fabrication of water-soluble cucurbit[8]uril (CB[8])-mediated supramolecular polymers by connecting the fluorinated azobenzene (FAB) containing monomers through host-enhanced heteroternary π-π stacking interactions. Benefiting from the unique visible-light-induced E→Z photoisomerization of the FAB photochromophores, the encapsulation behaviors between the CB[8] macrocycle and the monomers could be regulated upon visible light irradiation, resulting in the depolymerization of such CB[8]-mediated supramolecular polymers.

4.
Chem Commun (Camb) ; 53(39): 5396-5399, 2017 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-28451683

RESUMO

Linear tetrathiafulvalene (TTF) oligomers were synthesized, which could not only form a pleated TTF˙+ radical cation foldamer under oxidation conditions, but also interlocked with CBPQT4+ to form folded donor-acceptor [3]pseudorotaxane in the neutral state of TTF. Moreover, switchable transformation between these two folded supramolecular structures was achieved under the alternative regulation of the redox states of TTF units.

5.
Chem Commun (Camb) ; 53(53): 7266-7269, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28265612

RESUMO

We herein report the construction of a new heteropore COF which consists of two different kinds of micropores with unprecedented shapes. It exists as hollow microspheres and exhibits an extremely high volatile iodine uptake (up to 481 wt%) by encapsulating iodine in the inner cavities and porous shells of the microspheres.

6.
Chemistry ; 23(24): 5668-5672, 2017 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-28261879

RESUMO

Interlayer stacking of 2D covalent organic frameworks (COFs) plays a crucial role in determining not only the geometry of channels inside COFs but also the mobility of carrier transport between COF layers. However, though topological structures of 2D COFs monolayers can be precisely predicted through the structures of building blocks, factors affecting their interlayer stacking remain poorly understood. In this work, a truxene-based building block on which six methyl groups are introduced was designed. The condensation of it with 1,4-diaminobenzene or benzidine afforded 2D COFs with the methyl groups extending out-of-plane of the layers. A significant influence of the methyl groups on interlayer stacking of the COFs was revealed by the adoption of inclined packing of monolayers, which has never been experimentally observed before. This unprecedented stacking manner was confirmed by powder X-ray diffraction analysis, pore-size distribution analysis, and TEM investigation.

7.
Chem Commun (Camb) ; 53(16): 2431-2434, 2017 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-28164199

RESUMO

A model system has been established to construct two-dimensional (2D) covalent organic frameworks (COFs) by taking advantage of the variable orientation of imine bonds. During the assembly process, the imine bonds adopt an unprecedented heterodromous orientation to facilitate the formation of the COFs.

8.
Chem Commun (Camb) ; 52(98): 14085-14088, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27840880

RESUMO

Light-triggered photoisomerization of the azobenzene (AB) unit in bistable [2]rotaxanes can cause the shuttling of the macrocycle on the dumbbell, resulting in distinctive dual spectral variation characteristics: (1) the spectral change of the photochromic unit and (2) the variation of the charge-transfer band. By employing the CT bond region as an output signal, non-destructive readout of optical information could be achieved.


Assuntos
Luz , Rotaxanos/química , Compostos Azo/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrofotometria Ultravioleta
9.
Chemistry ; 22(49): 17784-17789, 2016 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-27778380

RESUMO

Integrating different kinds of pores into one covalent organic framework (COF) endows it with hierarchical porosity and thus generates a member of a new class of COFs, namely, heteropore COFs. Whereas the construction of COFs with homoporosity has already been well developed, the fabrication of heteropore COFs still faces great challenges. Although two strategies have recently been developed to successfully construct heteropore COFs from noncyclic building blocks, they suffer from the generation of COF isomers, which decreases the predictability and controllability of construction of this type of reticular materials. In this work, this drawback was overcome by a multiple-linking-site strategy that offers precision construction of heteropore COFs containing two kinds of hexagonal pores with different shapes and sizes. This strategy was developed by designing a building block in which double linking sites are introduced at each branch of a C3 -symmetric skeleton, the most widely used scaffold to construct COFs with homogeneous porosity. This design provides a general way to precisely construct heteropore COFs without formation of isomers. Furthermore, the as-prepared heteropore COFs have hollow-spherical morphology, which has rarely been observed for COFs, and an uncommon staggered AB stacking was observed for the layers of the 2D heteropore COFs.

10.
Chem Commun (Camb) ; 52(48): 7588-91, 2016 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-27220491

RESUMO

A two-dimensional (2D) supramolecular organic framework (SOF) has been constructed through the co-assembly of a triphenylamine-based building block and cucurbit[8]uril (CB[8]). Fluorescence turn-on of the non-emissive building block was observed upon the formation of the 2D SOF, which displayed highly selective and sensitive recognition of picric acid over a variety of nitroaromatics.

11.
J Am Chem Soc ; 138(14): 4710-3, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-27015785

RESUMO

It is very important to create novel topologies and improve structural complexity for covalent organic frameworks (COFs) that might lead to unprecedented properties and applications. Despite the progress achieved over the past decade, the structural diversity and complexity of COFs are quite limited. In this Communication, we report the construction of COFs bearing three different kinds of pores through the heterostructural mixed linker strategy involving the condensation of a D2h-symmetric tetraamine and two C2-symmetric dialdehydes of different lengths. The complicated structures of the triple-pore COFs have been confirmed by powder X-ray diffraction and pore size distribution analyses.

12.
Chem Asian J ; 11(6): 839-43, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-26812389

RESUMO

A hexaazatriphenylene (HAT) derivative (compound 1) that bears four n-octyl chains and two thienyl groups was designed and synthesized. Further light-induced oxidation coupling reaction led to thienyl-fused compound 2. Their photophysical and electrochemical properties and self-assembly behavior have been investigated by UV/Vis, fluorescence, and (1)H NMR spectroscopies, cyclic voltammetry (CV), scanning electron microscopy (SEM), and powder X-ray diffraction (PXRD). Although the difference in compounds 1 and 2 only lie in one single bond that connects the two thienyl segments, they displayed remarkably different properties, revealing an interesting structure-property relationship.

13.
Chem Commun (Camb) ; 50(59): 7982-5, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-24915053

RESUMO

Two new types of supramolecular polymers have been constructed via the self-assembly of rigid rod-like monomers and cucurbit[8]uril (CB[8]) in water. These supramolecular polymers possessed rigid backbones and further aggregated into stick-like bunched fibres.

14.
Chem Asian J ; 9(3): 754-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24458482

RESUMO

Chiral amplification is an interesting phenomenon in supramolecular chemistry mainly observed in complicated systems in which cooperative effect dominate. Herein, chiral, supramolecular, propeller-like architectures have been constructed through coassembly of an achiral disk-shaped molecule and chiral amino acid derivatives driven by intermolecular hydrogen bonding. Both the "sergeants-and-soldiers" principle and "majority-rules" effect are applicable in these discrete four-component supermolecules, which are the simplest supramolecular system ever reported that exhibit chiral amplification.


Assuntos
Substâncias Macromoleculares/química , Substâncias Macromoleculares/síntese química , Aminoácidos/química , Ligações de Hidrogênio
15.
Chem Commun (Camb) ; 47(5): 1524-6, 2011 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-21113515

RESUMO

A series of oligo(quinoxalineethylene)s which exhibit n-type semi-conducting features were synthesized, and adding Ag(+) to their solutions induced the backbones to adopt coplanar conformations due to Ag(+)-N coordination.


Assuntos
Oligonucleotídeos/química , Oligonucleotídeos/síntese química , Quinoxalinas/química , Compostos de Prata/química , Modelos Moleculares , Conformação Molecular , Estrutura Molecular
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