Conducting polymer wires in mesopore hosts

Nanometer-size conducting structures are of great interest in view of fundamental issues and potential applications. We explore the inclusion chemistry of conjugated polymers and graphite-like materials as a means to create such structures. Novel mesoporous materials with pore diameters in the 3 nm range (MCM-41) are used as hosts. Monomer molecules are introduced via vapor or solution transfer and polymerized either by included or external reagents. The properties of the conjugated systems are studied while encapsulated or after dissolution of the host. In the case of polyaniline formed on oxidation of aniline with persulfate, microwave absorption shows the presence of conducting filaments in the host channels. The above systems are compared with graphite-type material encapsulated in MCM-41 by first forming a precursor polymer such as polyacrylonitrile that is pyrolyzed at 500-800°C. These polymer chains are the first nanometer-size conducting filaments stabilized in a well-defined channel host

Overriding Default Calling Context In Javascript

The article is devoted to overriding the context of function calls in JavaScript. Let's consider all possible cases of setting the context of functions. We will analyze how effective the existing mechanisms are. As a result, an alternative way to set the context of functions will be formulated

Electrochemistry and spectroelectrochemistry of polymers based on D-A-D and D-D-D bis( N -carbazolyl) monomers, effect of the donor/acceptor core on their properties

In this work we present electropolymerization of monomers of an unusual type using N-linked carbazole units to limit their conjugation. The polymers thus obtained have limited conjugation through the backbone. Using donor-acceptor-donor (D-A-D) and donor-donor-donor (D-D-D) monomers we evaluate the effects of the presence (or absence) of charge transfer states on synthesized electropolymers. The use of a D-A-D monomer resulted in obtaining an ambipolar polymer with quasi-reversible reduction

Consequence of one-electron oxidation and one-electron reduction for aniline

Quantum-chemical calculations were performed for all possible isomers of neutral aniline and its redox forms, and intramolecular proton-transfer (prototropy) accompanied by π-electron delocalization was analyzed. One-electron oxidation (PhNH2 – e → [PhNH2]+•) has no important effect on tautomeric preferences. The enamine tautomer is preferred for oxidized aniline similarly as for the neutral molecule. Dramatical changes take place when proceeding from neutral to reduced aniline. One-electron reduction (PhNH2 + e → [PhNH2]-•) favors the imine tautomer. Independently on the state of oxidation, π- and n-electrons are more delocalized for the enamine than imine tautomers. The change of the tautomeric preferences for reduced aniline may partially explain the origin of the CH tautomers for reduced nucleobases (cytosine, adenine, and guanine)