Corresponding Monomers (corresponding + monomer)

Distribution by Scientific Domains

Selected Abstracts

Synthesis and characterization of a new disubstituted polyacetylene containing indolylazo moieties in side chains

Zhen Li
Abstract A new disubstituted polyacetylene with indolylazo moieties in its side chains (9) was synthesized by a post functionalization strategy, which was difficult, or perhaps impossible, to obtain from the direct polymerization of its corresponding monomer. The polymer is soluble in common solvents and thermally stable. The polymer shows good optical transparency with an absorption maximum at 393 nm and a band edge at ,530 nm. Its poled film exhibits a resonant d33 value of 17.9 pm/V and its optical nonlinearity is resistant to thermal decay at up to 147 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5672,5681, 2006 [source]

Role of the Special Pair in the Charge-Separating Event in Photosynthesis

Hidekane Ozeki Dr.
Abstract We synthesized special-pair/electron-acceptor systems consisting of a complementary slipped cofacial dimer of imidazolyl-substituted zinc porphyrin, bearing pyromellitdiimide as the electron acceptor. In the case of the dimer, the first and second oxidation potentials were split into a total of four peaks in the differential pulse voltammetry measurement. Furthermore, the shift values of the first oxidation potentials obtained by changing the solvent polarity for the dimer were almost half of those observed for the monomer. These results indicate that the radical cation is delocalized over the whole , system of the dimer. Time-resolved transient absorption measurements revealed that, relative to the corresponding monomer, the dimer accelerated the charge separation rate, but decelerated the charge recombination rate. The smaller reorganization energy of the slipped cofacial dimer relative to that of the monomeric system demonstrates the significance of the special-pair arrangement for efficient charge separation in photosynthesis. [source]

Synthesis and Properties of Novel Cross-Linked Fluoroalkyl End-Capped Oligomeric Nanoparticles Containing Adamantane Units

Masaki Mugisawa
Abstract Fluoroalkyl end-capped cooligomers that contain both oxime-blocked isocyanato and hydroxyadamantyl segments are prepared by the cooligomerization of fluoroalkanoyl peroxide with the corresponding monomers under mild conditions. This fluorinated cooligomer affords new cross-linked fluoroalkyl end-capped cooligomeric nanoparticles that contain adamantane segments by the deprotecting reaction of oxime-blocked isocyanato segments in cooligomers in excellent to moderate isolated yield. A variety of cross-linked fluoroalkyl end-capped cooligomeric nanoparticles that contain adamantane segments are also prepared by similar deprotecting reactions with this fluorinated cooligomer in the presence of adamantane-1,5-diol. Furthermore, we have prepared cross-linked fluoroalkyl end-capped cooligomers that contain oxime-blocked isocyanato segments by the use of 2-hydroxyethyl acrylate and poly(ethylene glycol)-containing methacrylate monomer as comonomers, respectively. However, the deprotecting reactions of the oxime-blocked isocyanato segments in the cooligomers do not afford the expected nanoparticles, and these cross-linked cooligomers are found to show a gelling characteristic. The thermal stability of these cross-linked fluorinated cooligomeric nanoparticles that contain adamantane segments increases significantly compared to that of the parent fluorinated cooligomer. More interestingly, the thermal stability of these cross-linked fluorinated nanoparticles is almost the same as that of the fluoroalkyl end-capped acrylic acid oligomer/SiO2 nanocomposites (content of SiO2 in composites: 70%). In addition, these cross-linked fluorinated nanoparticles have been applied to the surface modification of traditional organic polymers such as poly(methyl methacrylate) to exhibit a good oleophobicity imparted by fluorine on their surface. [source]

Electrochemical polymerization of chiral pyrrole derivatives in electrolytes containing chiral camphor sulfonic acid

GY Han
Abstract N -Substituted pyrrole derivatives with chiral side groups have been synthesized and electrochemically polymerized in acetonitrile containing tetrabutylammonium perchlorate (TBAClO4) and (S)-(+)-camphor-10-sulfonic acid ((S)-(+)-CSA) or (R)-(,)-camphor-10-sulfonic acid ((R)-(,)-CSA). The resulting N -substituted polypyrrole films were characterized by cyclic voltammetry, infrared, Raman and X-ray photoelectron (XPS) spectroscopies. XPS results demonstrated that the as-grown polymer films are preferably doped by CSA anions when the monomer and the CSA anion have the same optical rotation dispersion (ORD). Furthermore, the conductivities of the polymers synthesized in the media containing CSA with the same ORD of the corresponding monomers were measured to be about 2,10 times higher than those of polymers obtained from electrolytes without CSA. Copyright © 2004 Society of Chemical Industry [source]

Synthesis of Monomeric and Dimeric Acridine Compounds as Potential Therapeutics in Alzheimer and Prion Diseases

René Csuk
Abstract Starting from substituted 9-chloroacridines, a series of quinacrine and spacered dimeric acridine compounds was prepared. Their ability to interrupt the protein association of prion- and Alzheimer-specific proteins and Ab peptides was explored using a fast screening system based on FACS analysis. The bis-acridines displayed a higher activity than the corresponding monomers. Among these derivatives, best results were obtained with the 2,4-dimethoxy-6-nitro compound 7h for A,-peptides and the 2-methoxy-6-nitro compound 7f for PrP. [source]