نتایج جستجو برای: structural counts phenylene
تعداد نتایج: 449460 فیلتر نتایج به سال:
Water-soluble poly(phenylene ethynylene) carrying beta-cyclodextrin was prepared; the polymer exhibited a fluorescence color change or quenching, depending on the kind of guest.
A water-soluble poly(m-phenylene) bearing an achiral oligo(ethylene oxide) chain at the 5-position was synthesized by the Ni(0)-mediated homo-coupling polycondensation of a 3,5-dibromophenol monomer. The poly(m-phenylene) adopted a single helical conformation in protic media and self-assembled into a double helix in water through aromatic interaction, while it took a random-coil conformation in...
Poly(phenylene ethynylene)s bearing a high density of branched amphiphilic side-chains self-assemble at the air-water interface and in water-potassium dodecanoate-decanol lyotropic liquid crystals.
[structure: see text]. New poly(phenylene ethynylene)s (PPEs) and poly(phenylene vinylene)s (PPVs) that are highly emissive in solution and thin films were prepared utilizing palladium-catalyzed cross-coupling between new 1,4-diiodo-2,3-dialkoxybenzene- and iptycene-containing monomers. The absorption and emission spectra of the resulting polymers consistently showed a significant blue shift re...
We report the results of light scattering, absorption, excitation, and emission spectroscopy of three polyphenylene vinylene (PPV) derivatives; poly[Zmethoxy, 5-(2’-ethyl-hexyloxy-p-phenylenevinylene] (MEH-PPV), poly[Zbutoxy, 5-(2’-ethyl-hexyloxy-p-phenylene-vinylene] (BEH-PPV), and poly[2-dicholestanoxy-p-phenylene-vinylene] (BCHA-PPV) in solution with p-xylene. We find that increasing the siz...
The normalized Laplacian is extremely important for analyzing the structural properties of non-regular graphs. molecular graph generalized phenylene consists n hexagons and 2n squares, denoted by Ln6,4,4. In this paper, using polynomial decomposition theorem, we have investigated spectrum Ln6,4,4 consisting eigenvalues symmetric tri-diagonal matrices LA LS order 4n+1. As an application, signifi...
Multiresponsive materials that display predefined photoluminescence color changes upon exposure to different stimuli are attractive candidates for advanced sensing schemes. Herein, we report a cyano-substituted oligo(p-phenylene vinylene) (cyano-OPV) derivative that forms five different solvent-free solid-state molecular assemblies, luminescence properties of which change upon thermal and mecha...
[structure: see text]. Flash vacuum pyrolysis (FVP) of linear [3]phenylene affords its angular counterpart and the same mixture of polycyclic aromatic hydrocarbon isomers as that observed on FVP of angular [3]phenylene. A mechanism, supported by a 13C labeling study, is proposed to explain these results.
The primary adsorption sites for Ar and N2 within metal-organic framework-5, a cubic structure composed of Zn4O(CO2)6 units and phenylene links defining large pores 12 and 15 angstroms in diameter, have been identified by single-crystal x-ray diffraction. Refinement of data collected between 293 and 30 kelvin revealed a total of eight symmetry-independent adsorption sites. Five of these are sit...
Single-molecule study of phenylenevinylene oligomers revealed distinct spectral forms due to different conjugation lengths which are determined by torsional defects. Large spectral jumps between different spectral forms were ascribed to torsional flips of a single phenylene ring. These spectral changes reflect the dynamic nature of electron delocalization in oligophenylenevinylenes and enable e...
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