Multiple Adsorption of Polythiophene Layers on ITO/Glass Electrodes and Their Optical, Electrochemical, and Conductive Properties

Abstract

Polyelectrolyte multilayers containing electrochemically active polythiophenes have been constructed on ITO/glass substrates using the layer-by-layer adsorption deposition technique. Electrochemically active layers of poly(cyclopentadithienyl-alkylsulfonate), poly(cyclopentadithienyl-alkylammonium), and R,ω-bis(carboxyhexyl)sexithiophene were deposited with nonelectroactive layers of polyallylamine and polystyrenesulfonate. The first sequential adsorption of multilayers in which both the polycation and the polyanion are based on the same polythiophene is reported. UV-vis spectroscopy and cyclic voltammetry indicate a linear dependence of the amount of deposited polymer on the number of deposition cycles. The rate of deposition depends on the oxidation state of the polythiophene being 3 times lower for the oxidized polycationic polymer. Atomic force microscopy characterization of the layers has shown that flat monolayers are deposited with a progressive increase of roughness. Interposition of multiple nonelectroactive layers between the electrode and a single external electroactive polythiophene layer has allowed determination by cyclic voltammetry that each polythiophene layer interpenetrates the confining layers up to a three-layer distance. The conductivities of the multilayers along the surface and perpendicular to it are anisotropic depending on the layer alternation. The photoluminescence properties of the R,ω-bis-(carboxyhexyl)sexithiophene multilayers are the same for vacuum-deposited polycrystalline layers.

Electrochemistry of Poly(3,4‐alkylenedioxythiophene) Derivatives

“…[54] cyanovinylene 26, [55] ethynylene 27, [56] furan 28 and thiophene 29, [57] bithiophene 30 and 5,5¢-bisvinylene-bithiophene 31, [58] benzene 32 and biphenyl 33, [57] dialkoxybenzenes 34, [59] pyridine 35 and bipyridine 36, [60,61] carbazoles 37, [57,62,63] fluorenes 38, [64] sillole 39, [65] benzothiadiazole 40, [66] and tetrathiafulvene 41.…”

Self-assembled monolayers and electrostatically self-assembled multilayers of polyalkylviologens on sulfonate-modified gold and indium–tin–oxide electrodes

“…Though the extent of ATS coverage on ITO is documented [25], the amount of coverage which is produced in MPS and MEA priming of gold from ethanol is not reported. A QCM-based report details the MPS deposition from water [26].…”

Synthetic Routes toward Asymmetrically Substituted (Functionalized) 4H-Cyclopenta[2,1-b:3,4-b′]dithiophenes

“…One method consists of the synthesis of unsubstituted CPDT 1 followed by a nucleophilic substitution reaction, subtracting the protons on the 4-position, with alkyl halides, either in the presence of KOH as a base 11 or through stepwise lithiation and substitution. 12 For the latter case, a few examples of asymmetric 4,4-dialkyl substitution have been reported as well. 13 The synthesis of CPDT 1 is, however, quite laborious and involves a minimum of three steps with a rather low overall yield.…”

“…In continuation of previous synthetic endeavors toward Over the years, several multistep protocols have been reported affording (mostly dialkylated) CPDT materials. [10][11][12] In 2010, we have introduced an alternative three-step method (Scheme 1, vide infra). 9a The main benefit of this procedure is that it provides smooth access to asymmetrically dialkylated and/or functionalized CPDTs as well.…”