Substituent effects on the properties of stable aromatic free radicals. Oxidation-reduction potentials of triaryl-amine-triarylaminium ion systems

Hagopian, Laura E.; Köhler, Gabriele; Ri, Walter

doi:10.1021/j100866a050

Cited by 73 publications

(36 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The methylation of the para-position avoids dimerization of the triphenylamines due to electrochemical oxidation. [12] The monomers were synthesized according to the literature in a copper catalyzed Ullmann coupling of the accordant diphenylamine and bromobenzene followed by a Vilsmeyer reaction and a Wittig reaction to produce a polymerizable vinyl group. [13] The polymer for nanorod functionalization was polymerized by RAFT polymerization, which offers the opportunity to synthesize block copolymers with a low polydispersity index by a living radical mechanism (see Figure 1).…”

Section: Resultsmentioning

confidence: 99%

Liquid Crystalline Orientation of Semiconducting Nanorods in a Semiconducting Matrix

Zorn

Zentel

2008

Macromol. Rapid Commun.

View full text Add to dashboard Cite

This paper describes the synthesis of narrowly distributed block copolymers consisting of a hole conducting triarylamine block and an anchor block via RAFT polymerization. The anchor block is thereby introduced via a reactive ester approach. Block copolymers with dopamine anchor groups bind to oxidic semiconductors like TiO2, SnO2, and ZnO. Thus, it becomes possible to cover inorganic electron conducting (acceptor) nanomaterials with a corona of an organic hole conducting (donor) polymer like poly(triphenylamine), giving new hybrid materials. The poly(triphenylamine) grafted to inorganic nanorods allows the preparation of stable nanorod dispersions in appropriate solvents. At higher concentration the nanorods form liquid crystalline phases in various solvents and in a low Tg oligotriphenylamine matrix. This offers the potential to orient semiconducting inorganic nanorods in a hole conducting polymer matrix by self‐assembly.magnified image

show abstract

Section: Resultsmentioning

confidence: 99%

Liquid Crystalline Orientation of Semiconducting Nanorods in a Semiconducting Matrix

Zorn

Zentel

2008

Macromol. Rapid Commun.

View full text Add to dashboard Cite

show abstract

“…[114,115,187] Abgesehen von diesem Schutzgruppeneffekt garantieren die para-Substituenten nicht nur Stabilität, sondern erlauben auch die Durchstimmbarkeit des Oxidationspotentials der Triarylamin-Redoxzentren über einen weiten Bereich. [188,189] Des Weiteren erwiesen sich die optischen Absorptionseigenschaften der Bis(triarylamine) als vorteilhaft, weil die neutrale Spezies sowie das Radikalkation und -dikation jeweils charakteristische Banden (bei 350 nm für M und 750 nm für M + ) zeigen, die normalerweise nur wenig mit den breiten IV-CT-Banden überlappen, die weit in den NIRBereich verschoben sind. Bis(triarylamin)-Radikalkationen sind deshalb für die Analyse von IV-CT-Banden mit optischen Methoden gut geeignete Systeme.…”

Section: Bis(triarylamin)-radikalkationenunclassified

Organische gemischtvalente Verbindungen: ein Spielplatz für Elektronen und Löcher

2011

View full text Add to dashboard Cite

Gemischtvalente (MV) Verbindungen sind ausgezeichnete Modellsysteme, um grundlegende Elektronentransport(ET)‐ und Ladungstransfer(CT)‐Phänomene zu untersuchen. Diese sind in komplexen biophysikalischen Prozessen wie der Photosynthese, aber auch in artifiziellen elektronischen Bauteilen von großer Bedeutung. So sind organische MV‐Verbindungen effiziente Lochtransportmaterialien in organischen lichtemittierenden Dioden (OLEDs), Solarzellen und photochromen Fenstern. Die Bedeutung der organischen gemischtvalenten Chemie sollte jedoch weniger in ihrer direkten Anwendbarkeit gesehen werden, als vielmehr in dem riesigen Kenntnisschatz über Elektronentransferphänomene, der durch ihr Studium gewonnen wurde. Die große Vielfalt an organischen Redoxzentren und Brückeneinheiten, die zu MV‐Verbindungen kombiniert werden können, sowie die stete Weiterentwicklung von ET‐Theorien und ET‐Untersuchungsmethoden förderten das enorme Interesse an organischen MV‐Verbindungen in den letzten Jahrzehnten und zeigen das große Potential dieser Verbindungsklasse auf. Das Ziel dieses Aufsatzes ist es, das letzte Jahrzehnt der organischen gemischtvalenten Chemie zusammenzufassen und ihren Einfluss auf moderne funktionelle Materialien hervorzuheben.

show abstract

“…This unfavorable reaction can be avoided by either protecting the para positions of the triphenylamine group, or by stabilizing the radical cation with electron-rich groups. [26] Both are realized in PvDMTPA-b-PPerAcr, where the two para positions are blocked with methoxy substituents, which in addition increase the stability of the radical cation (Fig. 3).…”

Section: Cylic Voltammetrymentioning

confidence: 99%

Microphase‐Separated Donor–Acceptor Diblock Copolymers: Influence of HOMO Energy Levels and Morphology on Polymer Solar Cells

Sommer

Lindner

Thelakkat

2007

Adv Funct Materials

177

171

View full text Add to dashboard Cite

The synthesis of novel semiconducting donor–acceptor (D–A) diblock copolymers by means of nitroxide‐mediated polymerization (NMP) is reported. The copolymers contain functional moieties for hole transport, electron transport, and light absorption. The first block, representing the donor, is made up of either substituted triphenylamines (poly(bis(4‐methoxyphenyl)‐4′‐vinylphenylamine), PvDMTPA) or substituted tetraphenylbenzidines (poly(N,N′‐bis(4‐methoxyphenyl)‐N‐phenyl‐N′‐4‐vinylphenyl‐(1,1′‐biphenyl)‐4,4′‐diamine), PvDMTPD). The second block consists of perylene diimide side groups attached to a polyacrylate backbone (PPerAcr) via a flexible spacer. This block is responsible for absorption in the visible range and for electron‐transport properties. The electrochemical properties of these fully functionalized diblock copolymers, PvDMTPA‐b‐PPerAcr and PvDMTPD‐b‐PPerAcr, are investigated by cyclic voltammetry (CV), and their morphology is investigated by transmission electron microscopy (TEM). All diblock copolymers exhibit microphase‐separated domains in the form of either wire‐ or wormlike structures made of perylene diimide embedded in a hole‐conductor matrix. In single‐active‐layer organic solar cells, PvDMTPD‐b‐PPerAcr reveals a fourfold improvement in power conversion efficiency (η = 0.26 %, short‐circuit current (ISC) 1.21 mA cm–2), and PvDMTPA‐b‐PPerAcr a fivefold increased efficiency (η = 0.32 %, ISC = 1.14 mA cm–2) compared with its unsubstituted analogue PvTPA‐b‐PPerAcr (η = 0.065 %, ISC = 0.23 mA cm–2).

show abstract

Substituent effects on the properties of stable aromatic free radicals. Oxidation-reduction potentials of triaryl-amine-triarylaminium ion systems

Cited by 73 publications

References 0 publications

Liquid Crystalline Orientation of Semiconducting Nanorods in a Semiconducting Matrix

Liquid Crystalline Orientation of Semiconducting Nanorods in a Semiconducting Matrix

Organische gemischtvalente Verbindungen: ein Spielplatz für Elektronen und Löcher

Microphase‐Separated Donor–Acceptor Diblock Copolymers: Influence of HOMO Energy Levels and Morphology on Polymer Solar Cells

Contact Info

Product

Resources

About