Menue

Publications

Authors Kiriy, N. ; Bocharova, V. ; Kiriy, A. ; Stamm, M. ; Krebs, F.C. ; Adler, H. J.
Title Designing Thiophene-Based Azomethine Oligomers with Tailored Properties: Self-assembly and Charge Carrier Mobility
Date 16.11.2004
Number 12614
Abstract This paper describes synthesis and characterization of two thiophene-based azomethinesdesigned to optimize solubility, self-assembly, and charge carrier mobility. We found thatincorporation of azomethine and amide moieties in the <IMG SRC="/images/gifchars/alpha.gif" BORDER=0>,<IMG SRC="/images/gifchars/omega.gif" BORDER=0 >-position, and hexyl chains inthe <IMG SRC="/images/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-position of the quaterthiophene, considerably improves the self-assembly propertieswithout suppression of solubility. Self-assembly of azomethine oligomers with (QT-amide)and without amide moieties (QT-aniline) were monitored by UV-vis, XRD, and AFM.Although no changes in the UV-vis spectrum of QT-aniline is observed upon addition ofhexane to the solution in THF, the addition of hexane to QT-amide solution induces a redshift of <I><IMG SRC="/images/gifchars/lambda.gif" BORDER=0 ></I><SUB>max</SUB> and appearance of fine structure believed to be vibronic in nature. Theconcentration dependence of the solvatochromism gives strong support for the <I>inter</I>molecularorigin of this effect and clearly indicates that the planarization of the oligomer backbone isforced by the aggregation. Although, no clear signs of the molecular order for various QT-aniline films are observed by AFM, UV-vis, and XRD measurements, the QT-am<br />ide filmafter the annealing at 180 <IMG SRC="/images/entities/deg.gif">C displays important molecular and macroscopic orientations.The sum of charge carrier mobilities as determined by pulse-radiolysis time-resolvedmicrowave conductivity (PR-TRMC) technique for QT-aniline was shown to be below thedetectable limit; the mobility of QT-amide was determined to be 1 &#215; 10<SUP>-</SUP><SUP>2</SUP> cm<SUP>2</SUP> V<SUP>-</SUP><SUP>1</SUP> s<SUP>-</SUP><SUP>1</SUP>, whichis comparable with the mobilities of the best organic semiconductors. All these significantdifferences in properties of related compounds can be attributed to the hydrogen bondingbetween QT-amide molecules responsible for the observed self-assembly.
Publisher Chemistry of Materials
Wikidata
Citation Chemistry of Materials 16 (2004) 4765-4771
DOI https://doi.org/10.1021/cm049688v
Tags flexible polyelectrolyte molecules supramolecular organization microwave conductivity organic semiconductors derivatives polymers alpha omega-dihexylquaterthiophene polyazomethines thermochromism sexithiophenes

Back to list