Indolo[3,2‐b]carbazole‐based poly(arylene ethynylene)s through Sonogashira coupling for optoelectronic and sensing applications

• Published in: Journal of applied polymer science 2019-01, Vol.136 (2), p.n/a
• Main Authors: Vintu, M., Unnikrishnan, G., Shiju, E., Chandrasekharan, K.
• Format: Article
• Language: English
• Subjects: C band; Carbazoles; Chemical synthesis; Coupling; Fluorescence; Fourier transforms; indolo[3,2‐b]carbazole‐based polymers; Materials science; Mercury (metal); NMR; Nuclear magnetic resonance; Optical switching; optoelectronic properties; Optoelectronics; Photovoltaic cells; Polymers; Receptors; sensing; Solar cells; Sonogashira coupling; Thermal stability
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.46940

ABSTRACT Two indolo[3,2‐b]carbazole (ICZ)‐based polymers have been designed and synthesized using Sonogashira cross‐coupling based on dibromoindolo[3,2‐b]carbazoles and 2,7‐diethynylfluorene or 9,10‐diethynylanthracene. The 2, 8 positions of the ICZ moiety has been used for the bridging of arylene ethynylene structure to form the polymer backbone. The characterization has been done by Fourier transform infrared, proton nuclear magnetic resonance, ultraviolet–visible and (UV–vis) fluorescence spectroscopic methods. The polymers, moderately soluble in aprotic and chlorinated solvents, have been found to possess thermal stability above 300°C. The band gap examinations, executed through cyclic voltammetry and complemented by UV–vis studies, indicated their semiconducting nature and the possibility for their utilization for the fabrication of polymer solar cells and for optical switching applications. Interestingly, the new diethynylindolocarbazole systems have been found to act as Bronsted acid sensors as well as a Hg2+ receptors. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46940 New indolo[3,2‐b] carbazole‐based semiconducting polymers ICZP1 and ICZP2, possessing photostability, low‐lying HOMO, narrow band gap, and high charge mobility because of the combined effect of fused heterocyclic ring of indolocarbazole, anthracene, and fluorene have been reported. The materials are suitable for the fabrication of active layer in photovoltaic cells, NLO materials, and sensors.