Electrosynthesis and characterization of a novel electrochromic copolymer of N-methylpyrrole with cyclopenta[2,1-b:3,4-b′]dithiophene

Abstract

Electrochemical copolymerization of N-methylpyrrole (NMPy) and cyclopenta[2,1-b:3,4-b 0 ]dithiophene (CPDT) was performed in acetonitrile containing sodium perchlorate as a supporting electrolyte. Characterization of the resultant copolymer P(CPDTco-NMPy) was performed by cyclic voltammetry, UV-vis spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The P(CPDT-co-NMPy) film has distinct electrochromic properties and exhibits four different colors (reddish brown, pale khaki, pale sea green and light blue) under various potentials. The maximum contrast (DT%) and response time of the copolymer film at 750 nm were measured as 47.0% and 2.20 s, respectively. An electrochromic device (ECD) based on P(CPDT-co-NMPy) and poly(3,4-ethylenedioxythiophene) was constructed and characterized. The optical contrast (DT%) at 630 nm was found to be 40.2%, and the response time was measured as 1.77 s. The coloration efficiency of the device was calculated to be 476 cm 2 per C at 630 nm. The ECD also has satisfactory optical memories and redox stability.

Torsions of N-methylpyrrole and its cation

“…Pyrroles, including N-methylpyrroles, are key building blocks of many biomolecules, medicines 1,2 and molecular wires. 3 As such, an understanding their energy-level structure underpins their photophysics and photodynamics. N-methylpyrrole (NMP), has been the subject of a number of spectroscopic and photodissociation studies.…”

Electronic, vibrational, and torsional couplings in N-methylpyrrole: Ground, first excited, and cation states

“…Pyrroles, including N-methylpyrroles, are key building blocks of many biomolecules (e.g., tryptophan, haem B, melatonin, and phycobiliproteins), a range of medicines (including photomedicines), 1,2 metalloporphyrin-based metal-organic frameworks (MOFs), 3 and molecular wires. 4 N-methylpyrrole (NMP) has been the subject of a number of photodissociation studies, [5][6][7][8][9][10][11] which have compared and contrasted its behavior with that of pyrrole. 12 A detailed understanding of the photophysics and photodynamics of molecules relies on establishing the energy-level structure; as such, there have been a number of spectroscopic studies of NMP.…”

Smart copolymers of ditriphenylaminedithienothiophene with ethylenedioxythiophene for multicolor energy storage systems

“…Moreover, PEDOT with adjustable conductivities could be obtained applying well‐known synthetic methods such as in situ oxidative polymerization, electropolymerization and transition metal catalyzed coupling polymerization, among which electropolymerization offers tunable conductivity, film morphology and mechanical properties 15‐18 . Therefore, utilizing monomers with different properties may enhance the properties of the resultant copolymers 19‐22 . Thus, copolymerization could be an easy and effective way to obtain a polymer having low bandgap and enhanced electrochemical properties 23‐27 .…”