983 resultados para Modular coordination (Architecture)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A novel porous material constructed from p-sulfonatocalix[4]arene molecules and a Ag-I coordination polymer has been structurally characterized. The porous supramolecular complex features a bilayer arrangement of p-sulfonatocalix[4]arene molecules linked by a Ag-I-hmt (hmt: hexamethylene- tetramine) coordination polymer through metal-ligand bonding, hydrogen bonding and host-guest interactions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Here we present a simple wet-chemical approach to synthesize flower-like silver nanostrip assembling architecture at room temperature. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images indicate that these microstructures with the diameter of similar to 500nm exhibit hietarchical characteristic. X-ray diffraction (XRD), energy-dispersed X-ray spectroscopy (EDX) and Raman spectroscopy indicate that poly (o-diaminobenzene) (PDB) also exists in the silver hierarchical microstructure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using sodium dodecyl sulfate (SDS), a 3D microflowery indium hydroxide [In(OH)(3)] structure assembled from 2D nanoflakes was fabricated in a large quantity via a hydrothermal approach at relative low temperature. The obtained In(OH)(3) flowers exhibited a narrow size range between 4 and 6 mu m. The properties of these composites were characterized by XRD, EDX, FE-SEM, TEM, SAED, and TGA. In this work, both the use of urea and SDS and the amounts of these components played important roles in the formation of In(OH)3 with different nanostructures.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A porous material with cobalt-oxygen cluster framework has been synthesized hydrothermally, which possesses large and rigid channels and manifests strong antiferromagnetic interactions, and the pyridinedicarboxylate ligand exhibits two types of rare coordination modes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Two highly connected cobalt(II) and zinc(II) coordination polymers with tetranuclear metal clusters as the nodes of network have been prepared, being the first example of an 8-connected self-penetrating net based on a cross-linked alpha-Po subnet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A supramolecular complex [Cu(phen)(2)H2O]{[Cu(phen)(H2O)](2)[C6AS]}center dot 2.5H(2)O (phen = 1,10'-phenanthroline and C6AS = p-sulfonatocalix[6]arene) has been synthesized under hydrothermal condition, and characterized by IR spectroscopy, TG analysis and single crystal X-ray diffraction. In the structure, unprecedented 1D ({[Cu(phen)(H2O)](2)[C(6)AS]}(2-))(n) coordination chains (exactly being belts) are stacked into some 2D layers by the pi center dot center dot center dot pi stacking interactions, which are further interconnected into a 3D extended structure by hydrogen bonding.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this article, highly rough and stable surface enhanced Raman scattering (SERS)-active substrates had been fabricated by a facile layer by-layer technique. Unique lambda-DNA networks and CTAB capped silver nanoparticles (AgNP) were alternatively self-assembled on the charged mica surface until a desirable number of bilayers were reached. The as-prepared hybrid architectures were characterized by UV-vis spectroscopy, tapping mode atomic force microscopy (AFM) and confocal Raman microscopy, respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A new approach to one-dimensional organization of gold nanoparticles (2-4 nm) is described, using poly(4-vinylpyridine) (P4VP) molecular chain as a template with the mediation of free Cu2+ ion coordination. The assembly was conducted on freshly prepared mica surfaces and in aqueous solution, respectively. The surface assembly was characterized by tapping mode atomic force microscopy (AFM), observing the physisorbed molecules in their chain-like conformation with an average height of 0.4 nm.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Single-crystal tubular products on the millimetre scale have been synthesized from water-soluble calixarene and phenanthroline in the presence of lanthanides by a hydrothermal method, in which the extended structures contain some 1D infinite channels.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The title compound, [Cu-2(C9H10NO3)(2)(NO3)(2)(C10H8N2)-(H2O)(2)](n), contains Cu-II atoms and L-tyrosinate (L-tyr) and 4,4'-bipyridine (4,4'-bipy) ligands in a 2:2:1 ratio. Each Cu atom is coordinated by one amino N atom and two carboxylate O atoms from two L-tyr ligands, one N atom from a 4,4'-bipy ligand, a monodentate nitrate ion and a water molecule in an elongated octahedral geometry. Adjacent Cu atoms are bridged by the bidentate carboxylate groups into a chain. These chains are further linked by the bridging 4,4'-bipy ligands, forming an undulated chiral two-dimensional sheet. O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds connect the sheets in the [100] direction. This study offers useful information for the engineering of chiral coordination polymers with amino acids and 4,4'-bipy ligands by considering the ratios of the metal ion and organic components.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the mixed-metal complex catena-poly[bis[diaquasilver(I)] [bis[aquacopper(II)]-mu(3)-pyridine-2,5-dicarboxylato-2': 1: 1'kappa N-5,O-2: O-5: O-5, O-5'-mu-pyridine-2,5-dicarboxylato-2: 1 kappa(4) N, O-2: O-5, O-5'-disilver(I)-mu(3)-pyridine-2,5-dicarboxylato-1: 1': 2 '' kappa(5) O-5, O-5': O-5: N, O-2-mu pyridine-2,5-dicarboxylato-1': 20 ''kappa(4) O-5, O-5': N, O-2] hexahydrate], {[Ag(H2O)(2)][AgCu(C7H3NO4)(2)(H2O)] center dot 3H(2)O}(n), a square-pyramidal Cu-II center is coordinated by two N atoms and two O atoms from two pyridine-2,5-dicarboxylate (2,5-pydc) ligands and a water molecule, forming a [Cu(2,5-pydc)(2)-( H2O)](2-) metalloligand. One Ag I center is coordinated by five O atoms from three 2,5-pydc ligands and, as a result, the [Cu(2,5-pydc)(2)(H2O)](2-) metalloligands act as linkers in a unique mu(3)-mode connecting Ag-I centers into a one-dimensional anionic double chain along the [101] direction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Morphological control of nanomaterials is of great interest due to their size and shape-dependent chemical and physical properties and very important applications in many fields such as biomedicine, sensors, electronics and others. In this paper, we reported a simple strategy for synthesizing gold nanowire assembling architecture at room temperature. It is found that two important factors, the proper volume ratio of ethanol to water and poly(vinyl pyrrolidone) (PVP), will play important roles in synthesizing flower-like short gold nanowire assembling spheres. Furthermore, the obtained flower-like gold assembling spheres with high surface-to-volume ratio have been employed as enhancing materials for electrochemical sensing H2O2. The present electrochemical sensing platform exhibited good electrocatalytic activity towards the reduction of H2O2. The detection limit for H2O2 was found to be 1.2 mu M, which was lower than certain enzyme-based biosensors.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Novel one-dimensional europium benzene-1,3,5-tricarboxylate compressed nanorods have been synthesized oil it large scale through direct precipitation in solution phase under moderate conditions without the assistance of any surfactant, catalyst, or template. The obtained nanorods have widths of about 50-100 not, thicknesses of 10-20 nm, and lengths ranging from a few hundred nanometers to several micrometers. X-ray powder diffraction. elemental analysis, Fourier transform infrared Studies, and thermogravimetric and differential thermal analysis show that the nanorods have the structural formula of Eu(1,3,5-BTC)center dot 6H(2)O. Upon UV excitation, these nanorods exhibit a highly efficient luminescence. which comes from the Eu3+ ions. Moreover, Eu2O3 nanorods Could also be obtained via a thermal decomposition method using the corresponding complex as a precursor. This synthetic route is promising for the preparation of other one-dimensional crystalline nanomaterials because of its simplicity and the low cost of the starting reagents.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Supramolecular organized multilayers were constructed by multiwalled carbon nanotubes modified with ferrocene-derivatized poly(allylamine) redox polymer and glucose oxidase by electrostatic self-assembly. From the analysis of voltammetric signals and fluorescence results, a linear increment of the coverage of enzyme per bilayer was estimated, which demonstrated that the multilayer is constructed in a spatially ordered manner. The cyclic voltammograms obtained from the indium tin oxide (ITO) electrodes coated by the (Fc-PAH@CNT/GOx)(n) multilayers revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers; that is, the sensitivity is tunable by controlling the number of bilayers associated with ITO electrodes. The incorporation of redox-polymer-functionalized carbon nanotubes (CNT) into enzyme films resulted in a 6-10-fold increase in the glucose electrocatalytic current; the bimolecular rate constant of FADH(2) oxidation (wiring efficiency) was increased up to 12-fold. Impedance spectroscopy data have yielded the electron diffusion coefficient (D-e) of this nanostructure to be over 10(-8) cm(2) s(-1), which is typically higher than those systems without CNT by at least a factor of 10, indicating that electron transport in the new supramolecular architecture was enhanced by communication of the redox active site of enzyme, redox polymer, and CNT.