197969-58-7Relevant articles and documents
Electroluminescent properties of novel fluorene derivatives with aromatic amine moieties
Kay, Kwang-Yol,Kim, Jung-Hoon,Kim, Sun-Ho,Park, Ho-Cheol,Park, Jong-Wook
, p. 121 - 128 (2006)
2,7-Bis[(4-diphenylamino)phenylvinylene]-9,9-diethylfluorene(BDPDF, 1) and 2,7-bis[(9-ethyl-3-carbazolylvinylene)-9,9-diethylfluorene(BECDF, 2) have been synthesized and characterized. To evaluate electroluminescent performance, compound 1 and 2 were used
Fluorenes substituted with fluorophenyl, difluorophenyl or trifluorophenyl fragments as materials for organic light emitting diodes
Krucaite,Tavgeniene,Stulpinaite,Sipaviciute,Buika,Zaleckas
, p. 173 - 179 (2016)
9,9-Diethylfluorenes substituted with two fluorophenyl, difluorophenyl or trifluorophenyl fragments were synthesized by the multi-step synthetic rout. The materials were characterized by 1H NMR spectroscopy, mass spectrometry, differential scanning calorimetry and thermogravimetric analyses. Some of the electro-active derivatives could form thin amorphous films and were tested as solution processed hole transporting layers in organic light- emitting diodes with Alq3 as the emitter and electron transporting material. Some of the electroluminescent devices demonstrated turn voltage of 5.5?V, a maximal photometric efficiency of about 1.0 cd/A and maximum brightness exceeding 960 cd/m2 .
Synthesis, characterization and photophysical-theoretical analysis of compounds A-π-D. 1. Effect of alkyl-phenyl substituted amines in photophysical properties
Ortega,Montecinos,Cattin,Díaz,del Valle,Bernède
, p. 615 - 623 (2017)
The study of new dipolar A-π-D molecules, which have an acceptor (A) and donor (D) charge joined by a conjugate bridge, have been an attention focus in the recent years due their different properties. In the current work, a molecular system has been modified in order to compare the effect on properties, such as quantum yield. Thus, two series were generated (alkyl- and alkoxy-substituted) to determine if molecules with tertiary asymmetric amines change their optical properties and whether quantum yield is affected. The different products have been characterized by several techniques such as UV–Vis spectrophotometry, elemental analysis, NMR, FT-IR, mass spectroscopy and fluorescence spectroscopy. Furthermore, their behavior in eight organic solvents, dichloromethane, tetrahydrofuran, ethyl acetate, 1,4-dioxane, acetone, acetonitrile, dimethylformamide and dimethylsulfoxide were experimentally and theoretically studied. The quantum yields were higher for the alkyl-substituted series. Theoretically, the dihedral angles formed between the tertiary amine and carbonyl group moieties have a correlation with quantum yield values, helping to explain why they are higher in non-polar solvents. Consequently, the maximum quantum yield was obtained with (E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(methyl(phenyl)amino)-9H-fluoren-2-yl) vinyl)thiophen-2-yl)acrylic acid (M8-1) in 1,4-dioxane, reaching 98.8%.
[4]Cyclofluorene: Unexpected Influence of Alkyl Chain Length
Jeannin, Olivier,Poriel, Cyril,Quinton, Cassandre,Rault-Berthelot, Jo?lle,Sicard, Lambert
, p. 874 - 880 (2018)
Presented here is the study of a new example of [4]cyclofluorene, with ethyl chains on the bridgeheads. Its molecular structure was established by solution NMR spectroscopy and single-crystal X-ray diffraction. Three successive oxidation processes and one reversible reduction were observed through cyclic voltammetry. The optical properties were characterized both in solution and thin film by UV/visible spectroscopy as well as stationary and time-resolved fluorescence. It was found that this [4]cyclofluorene displays different characteristics compared with the other [4]cyclofluorenes substituted by methyl or propyl chains: a simple modification of the chain length induces a non-negligible effect on the emission properties, which must be linked to the specific arrangement of the fluorene units. Furthermore, single-crystal X-ray diffraction reveals the formation of a pseudo-tubular solid-state arrangement of fully symmetrical ring structures, which was not observed for the other members of the [4]cyclofluorenes family. This finding could open the way to modulation of properties of cyclofluorenes through alkyl chain engineering.
Electron Transfer around a Molecular Corner
Schmidt, Hauke C.,Larsen, Christopher B.,Wenger, Oliver S.
, p. 6696 - 6700 (2018/03/26)
The distance dependence of electron transfer (ET) is commonly investigated in linear rigid rod-like compounds, but studies of molecular wires with integrated corners imposing 90° angles are very rare. By using spirobifluorene as a key bridging element and by substituting it at different positions, two isomeric series of donor-bridge-acceptor compounds with either nearly linear or angled geometries were obtained. Photoinduced ET in both series is dominated by rapid through-bond hole hopping across oligofluorene bridges over distances of up to 70 ?. Despite considerable conformational flexibility, direct through-space and through-solvent ET is negligible even in the angled series. The independence of the ET rate constant on the total number of fluorene units in the angled series is attributed to a rate-limiting tunneling step through the spirobifluorene corner. This finding is relevant for multidimensional ET systems and grids in which individual molecular wires are interlinked at 90° angles.
Two-photon absorbing compounds and methods of making same
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, (2018/11/21)
A two-photon absorbing (TPA) compound is provided, along with a method of making same. The TPA compound has a general structural formula: where A is an acceptor moiety that is connected to m number of diarylaminofluorene arms (m=1-3); in each diarylaminofluorene arms, R is selected from linear or branched alkyl chains having a general formula CnH2n+1, where n is in a range from 2 to 25; where R1, R2, and R3 are independently selected from H or C1-C4 alkyls; where R4 is selected from C1-C5 alkyls; and wherein R5 through R10 are independently selected from H, alkoxyls, alkyls, or aryls. A may be benzothiazol-2-yl, benzo[1,2-d:4,5-d′]bisthiazole-2,6-diyl, thiazolo[5,4-d]thiazole-2,5-diyl-, 1,3,5-triazine-2,4,6-triyl, 1,3,5-triazine-2,4,6-triyl, benzo[1,2-d:3,4-d′:5,6-d″]tristhiazole-2,5,8-triyl-, or dithieno[3,2-b:2′,3′-d]thiophene-2,6-diyl-.