218608-72-1Relevant articles and documents
Rutheniumethynyl-triarylamine mixed-valence conjugated system: syntheses, (spectro-)electrochemistry, and theoretical calculations
Ou, YA-Ping,Hu, Yuxuan,Xu, Meng,Wang, Aihui,Liu, Sheng Hua
, p. 3385 - 3400 (2019)
We describe the synthesis and characterization of triarylamine ethynyl ruthenium conjugate (4-OMeC6H4)2N-{C6H4-4-C≡C-RuCp* (dppe)}, 3. Its electronic and spectroscopy properties are investigated by anodic voltammetry, IR and UV–vis–NIR spectroelectrochemistry, and density functional theory (DFT) calculations. Results indicate that 3 undergoes two well-defined single-electron redox processes and that the RuII/III process occurs prior to the N0/+ process as supported by IR spectra ν(C≡C) band changes from 3 to 3+ (Δν = 129 cm?1) and spin-density distribution calculations of 3+. TDDFT calculations further reveal the NIR characteristic bands of singly oxidized 3+ from experimental spectroscopic absorptions, and we observe NAr2→Ru charge transfer mixed with Ru-C≡C→phenyl bridge charge-transfer.
Direct iodination of electron-deficient benzothiazoles: Rapid access to two-photon absorbing fluorophores with quadrupolar D-π-A-π-D architecture and tunable heteroaromatic core
Fakis, Mihalis,Georgiou, Dimitris,Hrobárik, Peter,Nociarová, Jela,Osusky, Patrik,Polyzos, Ioannis,Rakovsky, Erik
, p. 3460 - 3465 (2021/05/31)
Direct iodination of benzothiazoles under strong oxidative/acidic conditions leads to a mixture of iodinated heteroarenes with 1-2 major components, which are easily separable and which structures depend on the I2 equivalents used. Among the unexpected bu
Oxidative C-H Homocoupling of Push-Pull Benzothiazoles: An Atom-Economical Route to Highly Emissive Quadrupolar Arylamine-Functionalized 2,2′-Bibenzothiazoles with Enhanced Two-Photon Absorption
Fakis, Mihalis,Georgiou, Dimitris,Gyepes, Róbert,Hrobárik, Peter,Nociarová, Jela,Osusky, Patrik,Polyzos, Ioannis,Smolí?ek, Maro?
, p. 5512 - 5517 (2021/07/31)
Copper(II)-catalyzed C-H/C-H coupling of dipolar 2-H-benzothiazoles end-capped with triphenylamine moieties affords highly fluorescent 2,2′-bibenzothiazoles with quadrupolar (D-π-A-π-D) architecture displaying large two-photon absorption (TPA) cross sections (543-1252 GM) in the near-infrared region. The notably higher TPA performance as compared to quadrupolar π-systems with a widely used 2,2′-bipyridine core, along with the ease of the synthesis and chelating N^N ability, makes the title biheteroaryl platform an attractive building block for a large scope of functional dyes exploiting nonlinear optical phenomena.
Monocarbazole/dicarbazole hole transport material as well as preparation method and application thereof
-
, (2020/11/23)
The invention discloses a monocarbazole/dicarbazole hole transport material as well as a preparation method and application thereof. The chemical structural general formula of the monocarbazole/dicarbazole hole transport material is shown as a formula I.
Luminescence Tunable Europium and Samarium Complexes: Reversible On/Off Switching and White-Light Emission
Chen, Jing,Xie, Ziyu,Meng, Lingyi,Hu, Ziying,Kuang, Xiaofei,Xie, Yiming,Lu, Can-Zhong
, p. 6963 - 6977 (2020/05/18)
Single-molecule functional materials with luminescence tunable by external stimuli are of increasing interest due to their application in sensors, display devices, biomarkers, and switches. Herein, new europium and samarium complexes with ligands having triphenylamine (TPA) groups as the redox center and 2,2′-bipyridine (bpy) as the coordinating groups and diketonate (tta) as the second ligand have been constructed. The complexes show white-light emission in selected solvents for proper mixtures of the emission from Ln3+ ions and the ligands. Meanwhile, they exhibit reversible luminescence switching on/off properties by controlling the external potential owing to intramolecular energy transfer from the Ln3+ ions to the electrochemically generated radical cation of TPA+. Time-dependent density functional theory (TD-DFT) calculations have been performed to study the electronic spectra. The proposed intramolecular energy transfer processes have been verified by density functional theory (DFT) studies.
Influence of Donor-Substituents on Triphenylamine Chromophores Bearing Pyridine Fragments
Tydlitát, Ji?í,Fecková, Michaela,le Poul, Pascal,Pytela, Old?ich,Klikar, Milan,Rodríguez-López, Julián,Robin-le Guen, Fran?oise,Achelle, Sylvain
, p. 1921 - 1930 (2019/02/25)
Efficient synthetic routes that combine different palladium-catalyzed cross-coupling reactions have been developed for the preparation of a new family of push-pull derivatives in which pyridine was used as the acceptor group and different para-substituted diphenylamines as the donor groups. All compounds showed absorption in the UV/Vis region and blue-green emission with high quantum yields. Significant red shifts were observed in the absorption and fluorescence emission maxima on increasing the electron-donating ability of the substituents or on incorporating a π-conjugated linker. This finding can be explained on the basis of enhanced intramolecular charge transfer (ICT). Strong emission solvatochromism confirmed the formation of an intramolecular charge-separated emitting state. The HOMO-LUMO energy gaps have been estimated by experimental electrochemical measurements and the results were interpreted with the aid of DFT calculations. The thermal behavior of all materials has also been studied by differential scanning calorimetry.
Panchromatic Push-Pull Dyes of Elongated Form from Triphenylamine, Diketopyrrolopyrrole, and Tetracyanobutadiene Modules
Heyer, Elodie,Ziessel, Raymond
, p. 2109 - 2116 (2015/09/15)
Several symmetrical and unsymmetrical thiophene-functionalized diketopyrrolopyrrole chromophores bearing a bis(p-methoxyphenyl)-p-phenylamine substituent were synthesized through palladium-catalyzed cross-coupling reactions. Mono-substitution and di-substitution occur using either alkyne or borolane groups, allowing the preparation of mixed systems. The alkyne derivatives could be prepared in high yields, and are versatile building blocks for the [2+2] cyAcloaddition of tetracyanoethylene, leading to 1,1,4,4-tetracyanobuta-1,3-diene derivatives. These interesting push-pull molecules exhibit a rich redox activity, which is understandable in light of the behavior of appropriate reference compounds. These innovative and rationally designed scaffolds are highly colored, exhibiting high absorption coefficients and spanning an absorption range of more than 600A nm of the UV/Vis electromagnetic spectrum.
Charge transfer emission in oligotriarylamine-triarylborane compounds
Bonn, Annabell G.,Wenger, Oliver S.
, p. 4097 - 4107 (2015/05/05)
Donor-acceptor compounds exhibiting charge transfer emission are of interest in a variety of different contexts, for example, for nonlinear optical processes and for sensor applications. Recently investigated triarylamine-triarylborane compounds represent an important class of donor-acceptor systems, and we explored to what extent their charge-transfer properties can be further improved by using stronger amine donors and borane acceptors than prior studies. The oligotriarylamine employed here is a much stronger donor than previously used triarylamines containing single nitrogen centers. In order to increase the acceptor strength, the electron-accepting unit was equipped with two (instead of one) dimesitylboron substituents. In our comparative study, six donor-acceptor compounds were synthesized and investigated by cyclic voltammetry and optical spectroscopy. An increase of the donor strength through replacement of an ordinary triarylamine by an oligotriarylamine unit leads to the expected energetic stabilization of charge transfer (CT) excited states, but the emission solvatochromism is not more pronounced. The attempted increase of the acceptor strength by substitution of the acceptor moiety by two (instead of one) dimesitylboron groups leads to a drastic decrease of emission quantum yields. On the basis of these results, our purely experimental study provides fundamental guidelines for the design of new triarylamine-triarylborane donor-acceptor compounds with favorable charge-transfer emission properties.
Fluoride binding to an organoboron wire controls photoinduced electron transfer
Chen, Jing,Wenger, Oliver S.
, p. 3582 - 3592 (2015/05/27)
We demonstrate that the rates for long-range electron transfer can be controlled actively by tight anion binding to a rigid rod-like molecular bridge. Electron transfer from a triarylamine donor to a photoexcited Ru(bpy)32+ acceptor (bpy = 2,2′-bipyridine) across a 2,5-diboryl-1,4-phenylene bridge occurs within less than 10 ns in CH2Cl2 at 22 °C. Fluoride anions bind with high affinity to the organoboron bridge due to strong Lewis base/Lewis acid interactions, and this alters the electronic structure of the bridge drastically. Consequently, a large tunneling barrier is imposed on photoinduced electron transfer from the triarylamine to the Ru(bpy)32+ complex and hence this process occurs more than two orders of magnitude more slowly, despite the fact that its driving force is essentially unaffected by fluoride addition. Electron transfer rates in proteins could potentially be regulated via a similar fundamental principle, because interactions between charged amino acid side chains and counter-ions can modulate electronic couplings between distant redox partners. In artificial donor-bridge-acceptor compounds, external stimuli have been employed frequently to control electron transfer rates, but the approach of exploiting strong Lewis acid/Lewis base interactions to regulate the tunneling barrier height imposed by a rigid rod-like molecular bridge is conceptually novel and broadly applicable, because it is largely independent of the donor and the acceptor, and because the effect is not based on a change of the driving-force for electron transfer. The principle demonstrated here can potentially be used to switch between conducting and insulating states of molecular wires between electrodes. This journal is
Charge transfer through cross-hyperconjugated versus cross-π-conjugated bridges: An intervalence charge transfer study
Goeransson, Erik,Emanuelsson, Rikard,Jorner, Kjell,Markle, Todd F.,Hammarstroem, Leif,Ottosson, Henrik
, p. 3522 - 3532 (2013/11/19)
Recently there has been much interest in electron transfer and transport through cross-conjugated molecules as interesting test cases for the interplay between molecular and electronic structure as well as potential motifs in the design of new compounds f
