Dipyrido[3,2‐a:2′,3′‐c]phenazine‐Based Donor–Acceptor Aromatic Heterocyclic Compounds with Thienyl and Triphenylamino Chromophores at the 2,7‐ and/or 10,13‐Positions
TL;DR: A series of T- and H-shaped donor-acceptor (D-A) types of dipyrido[3,2-a:2',3'-c]phenazine (DPPZ)-based molecules, extended by thienyl and triphenylamino chromophores at the 2,7-(bottom) and/or 10,13-positions (top), have been designed and prepared successfully.
Abstract: A series of T- and H-shaped donor-acceptor (D-A) types of dipyrido[3,2-a:2',3'-c]phenazine (DPPZ)-based molecules, extended by thienyl and triphenylamino chromophores at the 2,7-(bottom) and/or 10,13-positions (top), have been designed and prepared successfully. Synthetic, structural, thermal, spectral, and computational comparisons have been carried out for related compounds because of their adjustable intramolecular charge-transfer properties. It is noted that a pair of structural isomers (5 and 6) has been obtained, respectively, where distinguishable UV/Vis and fluorescence spectra, electrochemical activity, thermal stability, and bandgaps are observed. Furthermore, compounds 6, 8, 10, 11, 13, and 15 exhibit excellent thermal stability, and the Td10 values for them are found to range from 524 to 646 °C, which can be regarded as one of the best groups of thermally stable compounds among organic small molecules. In addition, theoretical calculations were performed, and the structure-property relationships were examined to reveal the effects of the position and number of donor arms on the DPPZ acceptor core.
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TL;DR: In this paper, the authors present a comprehensive collection of publications devoted to dispersive liquid-liquid microextraction and their modalities as well as their applications, up to April 30, 2016.
Abstract: Novel solvent microextraction techniques are presently receiving a great deal of interest from analytical chemists, as confirmed by the constantly increasing number of published papers on the topic. The present overview offers a comprehensive collection of publications devoted to dispersive liquid–liquid microextraction and dispersive liquid-phase microextraction as well as their modalities. We cover the articles that were available online up to April 30, 2016. The applications of these techniques are summarized in the tables.
89 citations
TL;DR: A deep-red thermally activated delayed fluorescence molecule is reported with the feature of the T shape structure containing two triphenylamine donors substituted at both sides of planar dipyridophenazine (DPPZ) acceptor, which achieves the dramatically ~90 folds improved radiation rate constant and the nearly unitary reverse intersystem crossing (RISC) efficiency.
Abstract: Device simplification is of practical significance for organic light emitting diodes (OLEDs), and remains the great challenge for deep-red emitters. Herein, a deep-red thermally activated delayed fluorescence molecule (pTPA-DPPZ) is reported which features a T shaped structure containing two triphenylamine (TPA) donors, one either side of a planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional groups leads to limited but sufficient molecular packing for effective carrier transport. The neat pTPA-DPPZ film achieves an around 90-fold improved radiation rate constant of 107 s-1 and the nearly unitary reverse intersystem crossing (RISC) efficiency, as well as accelerated emission decays for quenching suppression. The high radiation and RISC result in a photoluminescence quantum yield of 87 %. The bilayer OLED based on the pTPA-DPPZ emissive layer achieved the record external quantum efficiencies of 12.3 % for maximum and 10.4 % at 1000 nits, accompanied by the deep-red electroluminescence with the excellent color purity.
87 citations
TL;DR: A summary of their recent extraordinary design inspired by letters of the alphabet, especially focusing on H-, L-, T-, V-, X-, and Y-shaped molecules, which turned out to be very efficient charge-transfer chromophores with tunable properties suitable for second-order nonlinear optics, two-photon absorption, reversible pH-induced and photochromic switching, photocatalysis, and intercalation.
Abstract: Push-pull molecules represent a unique and fascinating class of organic π-conjugated materials. Herein, we provide a summary of their recent extraordinary design inspired by letters of the alphabet, especially focusing on H-, L-, T-, V-, X-, and Y-shaped molecules. Representative structures from each class were presented and their fundamental properties and prospective applications were discussed. In particular, emphasis is given to molecules recently prepared in our laboratory with T-, X-, and Y-shaped arrangements based on indan-1,3-dione, benzene, pyridine, pyrazine, imidazole, and triphenylamine. These push-pull molecules turned out to be very efficient charge-transfer chromophores with tunable properties suitable for second-order nonlinear optics, two-photon absorption, reversible pH-induced and photochromic switching, photocatalysis, and intercalation.
79 citations
TL;DR: In this article, a post-modification strategy has been used to extend the terminal aldehyde radical into either an imine, acetal or α,β-unsaturated cyanoacetic ester group.
29 citations
TL;DR: In this article, the authors reported the design and synthesis of three new imidazo derivatives from 2,7-di-tert-butyl-pyrene-imidazol derivatives.
16 citations
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TL;DR: An overview of the use and impact of dialkylbiarylphosphine ligands in the Suzuki-Miyaura cross-coupling reaction and the utility of these ligands has been successfully demonstrated in a wide number of synthetic applications, including industrially relevant processes.
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