Fundamental concepts of 3,4-alkoxythiophene-based polymeric systems, from synthesis to applications

Abstract

Conducting polymers are one of the most interesting materials due to their broad range of applications, from sensing and energy storage to organic actuators. Among the different conducting polymers, the family of poly-3,4-alkoxy thiophenes stands out due to its exceptional electrical, optical, and chemical properties. The electro-donating effect of the 3,4-alkoxy groups favors the polymerization reaction, provides stereoregularity, and increases the effective conjugation. With poly-3,4-ethylendioxythiophene (PEDOT) as its flagship, this family has gained increasing attention in multiple fields of science, ranging from bioanalysis and electrochromic systems to microelectronics. This review outlines the most recent developments in the study of the 3,4-alkoxy thiophenes, from the synthetic routes of monomers to the fundamentals behind the polymerization and functionalization. Finally, conventional and unconventional applications of these materials in different fields of science, i.e., batteries and supercapacitors, electroanalysis, or optoelectronics, are discussed.