25069-40-3Relevant articles and documents
Modification of an ITO anode with a hole-transporting SAM for improved OLED device characteristics
Lee, Jaemin,Jung, Byung-Jun,Lee, Jeong-Ik,Chu, Hye Yong,Do, Lee-Mi,Shim, Hong-Ku
, p. 3494 - 3498 (2002)
Modification of inorganic electrodes has attracted much attention in the study of organic semiconductor devices. An ethoxysilane functionalized hole-transporting triphenylamine (TPA-CONH-silane) was synthesized and was self-assembled to form a monolayer o
Green-, Red-, and Infrared-Emitting Polymorphs of Sterically Hindered Push–Pull Substituted Stilbenes
Pauk, Karel,Luňák, Stanislav,R??i?ka, Ale?,Marková, Aneta,Mausová, Anna,Kratochvíl, Matou?,Melánová, Klára,Weiter, Martin,Imramovsky, Ale?,Vala, Martin
supporting information, p. 4341 - 4348 (2020/12/31)
The synthesis, XRD single-crystal structure, powder XRD, and solid-state fluorescence of two new DPA-DPS-EWG derivatives (DPA=diphenylamino, DPS=2,5-diphenyl-stilbene, EWG=electron-withdrawing group, that is, carbaldehyde or dicyanovinylene, DCV) are described. Absorption and fluorescence maxima in solvents of various polarity show bathochromic shifts with respect to the parent DPA-stilbene-EWGs. The electronic coupling in dimers and potential twist elasticity of monomers were studied by density functional theory. Both polymorphs of the CHO derivative emit green fluorescence (527 and 550 nm) of moderate intensity (10 % and 5 %) in polycrystalline powder form. Moderate (5 %) red (672 nm) monomer-like emission was also observed for the first polymorph of the DCV derivative, whereas more intense (32 %) infrared (733 nm) emission of the second polymorph was ascribed to the excimer fluorescence.
Guest Inclusion Modulates Concentration and Persistence of Photogenerated Radicals in Assembled Triphenylamine Macrocycles
Sindt, Ammon J.,Dehaven, Baillie A.,Goodlett, Dustin W.,Hartel, Johannes O.,Ayare, Pooja J.,Du, Yong,Smith, Mark D.,Mehta, Anil K.,Brugh, Alexander M.,Forbes, Malcolm D. E.,Bowers, Clifford R.,Vannucci, Aaron K.,Shimizu, Linda S.
supporting information, p. 502 - 511 (2020/01/03)
Substituted triphenylamine (TPA) radical cations show great potential as oxidants and as spin-containing units in polymer magnets. Their properties can be further tuned by supramolecular assembly. Here, we examine how the properties of photogenerated radical cations, intrinsic to TPA macrocycles, are altered upon their self-assembly into one-dimensional columns. These macrocycles consist of two TPAs and two methylene ureas, which drive the assembly into porous organic materials. Advantageously, upon activation the crystals can undergo guest exchange in a single-crystal-to-single-crystal transformation generating a series of isoskeletal host-guest complexes whose properties can be directly compared. Photoinduced electron transfer, initiated using 365 nm light-emitting diodes, affords radicals at room temperature as observed by electron paramagnetic resonance (EPR) spectroscopy. The line shape of the EPR spectra and the quantity of radicals can be modulated by both polarity and heavy atom inclusion of the encapsulated guest. These photogenerated radicals are persistent, with half-lives between 1 and 7 d and display no degradation upon radical decay. Re-irradiation of the samples can restore the radical concentration back to a similar maximum concentration, a feature that is reproducible over several cycles. EPR simulations of a representative spectrum indicate two species, one containing two N hyperfine interactions and an additional broad signal with no resolvable hyperfine interaction. Intriguingly, TPA analogues without bromine substitution also exhibit similar quantities of photogenerated radicals, suggesting that supramolecular strategies can enable more flexibility in stable TPA radical structures. These studies will help guide the development of new photoactive materials.
