Synthetic Principles for Bandgap Control in Linear pi-Conjugated Systems.

The merits of thiol-click chemistry and its potential for making new forays into chemical synthesis and materials applications are described Since thiols react to high yields under benign conditions with a vast range of chemical species, their utility extends to a large number of applications in the chemical, biological, physical, materials and engineering fields This critical review provides insight into emerging venues for application as well as new mechanistic understanding of this exceptional chemistry in its many forms (81 references)

Thiol-click chemistry: a multifaceted toolbox for small molecule and polymer synthesis

https://orbit.dtu.dk/files/4351774/2009%20PBI%20review%20Progress%20in%20Polymer%20Science%2034,%205,%20449-477.pdf

High temperature proton exchange membranes based on polybenzimidazoles for fuel cells

Two-dimensionally extended, polycyclic heteroaromatic molecules (heterocyclic nanographenes) are a highly versatile class of organic materials, applicable as functional chromophores and organic semiconductors. In this Review, we discuss the rich chemistry of large heteroaromatics, focusing on their synthesis, electronic properties, and applications in materials science. This Review summarizes the historical development and current state of the art in this rapidly expanding field of research, which has become one of the key exploration areas of modern heterocyclic chemistry.

Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds: Synthetic Routes, Properties, and Applications

Bei der Umsetzung von Triphenyl-phosphin-methylen und seinen in der Methylengruppe substituierten Derivaten mit Aldehyden und Ketonen wird der doppelt gebundene Sauerstoff gegen die Methylenreste ausgetauscht, wobei Triphenyl-phosphinoxyd und die entsprechenden ungesattigten Verbindungen entstehen. Der mit dieser neuen Methode sich abzeichnende praparative Fortschritt liegt darin, daβ die C=C–Bindung ohne Verschiebung am Ort der ursprunglichen C=O–Bindung ausgebildet wird.

Über Triphenyl-phosphin-methylene als olefinbildende Reagenzien (I. Mitteil.

Most organic polymeric materials melt below 200 °C and most of them begin to degrade rapidly at temperatures only slightly above 200°G. Thermally stable polymers are generally considered to be those which will withstand much higher temperatures without loss of strength or change of structure. In general we expect these materials to withstand at least 300°C in air and up to 500°C or higher in inert atmospheres. Polymers which show these properties are usually highly aromatic in structure, often with heterocyclic units, high melting, sometimes infusible and usually with low solubility in all solvents. This makes their fabrication very difficult and as a consequence limits their usefulness.

Thermally stable polymers

Wholly aromatic polybenzimidazoles were synthesized from aromatic tetraamines and difunctional aromatic acids and characterized as new thermally stable polymers. The melt polycondensation of aromatic tetraamines and the diphenyl esters of aromatic dicarboxylic acids was developed as a general procedure of wide applicability. Polybenzimidazoles containing mixed aromatic units in the chain backbone were prepared from 3,3′-diaminobenzidine, 1,2,4,5-tetraaminobenzene and a variety of aromatic diphenyl dicarboxylates. Phenyl 3,4-diaminobenzoate could also be polymerized by melt condensation to give poly-2,5(6)-benzimidazole. The polymers were characterized by a high degree of stability, showing great resistance to treatment with hydrolytic media and an ability to withstand continued exposure to elevated temperatures. Most of the polymers were infusible, but some had melting points above about 400°C. Many of the polymers exhibited no change in properties on being heated to 550°C. and showed a weight loss of less than 5% when heated under nitrogen for several hours to 600°C. The polymers were soluble in concentrated sulfuric acid and formic acid, producing stable solutions. Many of the polymers were soluble in dimethyl sulfoxide and some also in dimethylformamide. The inherent viscosities of a number of polymers in 0.5% dimethyl sulfoxide solution ranged from approximately 0.4 to 1.1. The higher polymers could be cast into stiff and tough films from formic acid and dimethyl sulfoxide solutions.

Carl S. Marvel

Papers

Thermally stable polymers

Polybenzimidazoles, new thermally stable polymers

Polymerization Reactions of Itaconic Acid and Some of Its Derivatives

Polyalkylene Sulfides from Diolefins and Dimercaptans

Pyridine analogs of chalcone and their polymerization reactions