Heterocyclic polymers azoles

Polyazoles, a class of high-strength heterocyclic polymers, are classified into three broad classes depending on the hetero atoms, like PBO, PBI, and PBT. However, their inherent insolubility in common organic solvents restricts their growth in practical applications. Different methods have been applied to enhance their solubility and processability. Incorporation of the fluorinated moiety in the polymer backbone is one of the important ways to improve the solubility and processability. The fluorinated poly azoles obtained... 

Dr. Wojciech Szczepankiewicz was born in Wolbrom, Poland, in 1959. He received his M.Sc. in polymer chemistry from the Silesian University of Technology in Gliwice, Poland, in 1985 and his Ph.D. in 1994 under the supervision of Prof. Jerzy Suwiriski at the same university. In 2002-03, he spent a period at Hasselt University (Belgium) with Prof. Dirk Vanderzande s lighting polymer research group. His research area is focused on the synthesis and reactivity of heterocyclic compounds in the azole and azine series. 

This may imply that the intermolecular coupling of various aryl halides with other heteroaromatic compounds may proceed. Indeed, it is now known that not only the special heteroaromatic halides but also usual aryl halides can react with a variety of five-membered aromatic heterocycles, including furans, thiophenes, and azole compounds such as M-substituted imidazoles, oxazoles, and thiazoles [133-137]. The arylation of azoles can be carried out using iodobenzoate immobilized on an insoluble polymer support [138]. Related intermolecular reactions of indole [139] and imidazole [140] derivatives have also been reported. 

Preparation. - A range of 1,3-dithianylphosphonium salts (218) has been prepared in the course of further studies of sulfur lone pair anomeric effects in these systems.Conventional quatemization reactions have been used in the synthesis of the salt (219) and a range of polymer-supported phosphonium salts (220). A new efficient route to salts of the type (221) has been developed. The of>-azolylalkylphosphonium salts (222) are readily accessible from the reactions of the corresponding a>-bromoalkylphosphonium salts and azoles. Routes to vinylphosphonium salts, e.g., (223), continue to be explored, and their reactivity utilised in the synthesis of phosphonium salts bearing heterocyclic substituents, e.g., (224). The betaine (225) has been... 

Fused azole systems with three heteroatoms can be represented by ben-zothiadiazole (BT), benzoselenodiazole (BSe), benzotriazole (BTA)." Among them the heterocycle BT is most widely used in conjugated co-polymers. Derivatives of BT have been widely used in organic electronic devices, especially in terms of electrochromic applications. While incorporated into the conjugated backbone these BT moieties bring to the polymeric material such properties as strong ICT transition dipole, multicolored electrochromism and efficient photoluminescence. 

Finally, it should be mentioned that the aromatic polyimides were the forerunners of a diversified group of thermostable polymers having heterocyclic moieties in their repeat units, for example, poly(benzimidazole)s, poly(benzox-azole)s, poly(benzthiazole)s, poly(benzobisthiazole)s, poly(l,3,4-oxadiazole)s. 

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