Electrochemical and spectrophotometric properties of polymers based on derivatives of di- and triphenylamines as promising materials for electronic applications

Abstract

Novel phenylamine-substituted derivatives, possessing different photochromic groups, were investigated. The electrochemical activity of the monomers and polymers were studied by usage of the electrochemical and spectroelectrochemical measurements. Heterocyclic side rings influence on the oxidation potential of monomers, decreasing its value below oxidation potential in comparison to parent phenylamine units. The removal of electron is easier for diphenylamine derivatives than for the triphenylamine ones. Electroactivity of monomers allows to polymerize them into macromolecule chains. Triphenylamine-based polymers are more stable as a result of the enlarged conjugated systems. Furthermore, the energy gap value of the final polymer can be reduced by introduction of additional branch into the monomer structure.

Conductance and spectroscopic mapping of EDOT polymer films upon electrochemical doping

“…The authors measured in situ UV/Vis/NIR absorption and explained the broad redox waves by coinciding redox potentials of the bi-EDOT and the TPA unit. By comparing the oxidation potentials of different di-and triphenylamine aromatic heterocyclic compounds, they deduced that the oxidation potentials for the bi-EDOT and the triphenylamine moieties are very similar, which results in broad oxidation waves [50]. The UV/Vis/NIR spectra in the charge sweep (figure 3) show in the neutral state (black line) two absorption bands at 440 nm and 680 nm.…”

Solution‐Processable Copolymers Based on Triphenylamine and 3,4‐Ethylenedioxythiophene: Facile Synthesis and Multielectrochromism

“…This is likely due to the nature of hyperbranched structure. Compared to the reported bandgaps of linear poly(triphenylamine)s (2.84–2.91 eV), [ 50 ] electropolymerized poly(TPA‐EDOT) (1.30–2.35 eV) [ 46,48 ] and PEDOT (1.65 eV), [ 52 ] it was found that bandgap values for P1 – P5 are generally in the range of 2.21–2.40 eV, which lie within a reasonable range, larger than that of linear PEDOT but smaller than that of structurally regular linear poly(triphenylamine)s.…”

“…Golba et al subsequently reported redox‐active TPA–EDOT‐based copolymers films obtained via electropolymerization of TPA and EDOT monomers over indium tin oxide (ITO) substrates, and their spectroelectrochemical studies showed the emergence of infrared absorption with increasing positive voltage applied. [ 48 ] In Hicks’ work, thin film EC devices fabricated from the as‐prepared polymer displayed two reversible oxidation peaks in cyclic voltammetry studies, and therefore, only exhibited two‐color switching between green and blue in the neutral and oxidized states, respectively. [ 47 ] Likewise, the polymer reported by Zhao exhibited neutral lime green to blue switching upon electro‐oxidative doping, but with two more similar intermediary color states of green and teal (a blue‐green color).…”