198964-46-4Relevant articles and documents
Synthesis and ring opening reaction of octaoctyl substituted [2.2.2.2](2,7)-fluorenophanetetraene by photooxidation
Yu, Chin-Yang,Chen, Yu-Chi,Wang, Chao-Chi
, p. 14116 - 14121 (2017)
Octaoctyl substituted fluorenophanetetraene has been synthesized from its corresponding octaoctyl substituted tetrathia[3.3.3.3]fluorenophane followed by benzyne Stevens rearrangement, oxidation and thermal elimination. The solid-state structure of octaoctyl substituted [2.2.2.2](2,7)-fluorenophanetetraene reveals that fluorene units are connected by cis vinylenes and alkyl chains are located inside and outside the rings. The photooxidation reaction of the fluorenophanetetraene was carried out in a dilute solution under UV light irradiation to give all trans linear fluorenevinylene with aldehyde end groups. The optical properties of the fluorenophanetetraene and its linear compound generated by photooxidation have been investigated and compared. The fluorescence quantum yield of the fluorenophanetetraene in solution is much lower than that of its linear compound generated by photooxidation due to shorter effective conjugation lengths; however, the fluorescence intensity of the fluorenophanetetraene in the solid state is much higher than that of its linear compound generated by photooxidation possibly due to weak intermolecular interaction.
2,7-Dibromo-9,9-dioctylfluorene-Chloroform (1/0.25)
Leclerc, Mario,Ranger, Maxime,Belanger-Gariepy, Francine
, p. 799 - 801 (1998)
In the solid state, the title compound, C29H40Br2.-0.25CHCl3, crystallizes in the tetragonal system. The fluorene ring system is perfectly planar. The torsion angles in the octyl chains are all trans. These octyl chains are all orthogonal to the aromatic ring and are in the ab plane of the unit cell. The stacking of aromatic units is non-existent. In the cyclopentadiene ring, the angle at the benzilic carbon is 101.1 (3)° and is smaller than other angles in this part of the fluorene ring system.
Facile synthesis of fluorene-based π-conjugated polymers via sequential bromination/direct arylation polycondensation
Saito, Hitoshi,Kuwabara, Junpei,Kanbara, Takaki
, p. 2198 - 2201 (2015)
The synthesis of fluorene-based π-conjugated polymers via sequential bromination and Pd-catalyzed direct arylation polycondensation was demonstrated; the protocol allows dual functionalization of each aromatic monomer in one-pot fashion. This synthetic protocol afforded the corresponding polymers with high molecular weights in good yields (up to yield 80%, Mn 34,500).
Synthesis, structure, and optoelectronic properties of phosphafluorene copolymers
Chen, Run-Feng,Zhu, Rui,Fan, Qu-Li,Huang, Wei
, p. 2913 - 2916 (2008)
(Chemical Equation Presented) Copolymers of phosphafluorenes are obtained through Suzuki copolymerization. The phosphorus-containing copolymers show unique optical, electrochemical, and optoelectronic properties. Blue and white electroluminescence can be
A supramolecular approach to lithium ion solvation at nanostructured dye sensitised inorganic/organic heterojunctions
Park, Taiho,Haque, Saif A.,Potter, Robert J.,Holmes, Andrew B.,Durrant, James R.
, p. 2878 - 2879 (2003)
A novel arylamine based hole transporting material (HTM) with tetraethylene glycol (TEG) side groups is reported. Lithium ions solubilised by the TEG groups are employed to modulate interfacial electron transfer reactions at a dye sensitised TiO2/su
Carbazole/fluorene based conjugated small molecules: Synthesis and comparative studies on the optical, thermal and electrochemical properties
Irfan, Madiha,Belfield, Kevin D.,Saeed, Aamer
, p. 48760 - 48768 (2015)
A series of new molecular materials with varying carbazole and fluorene contents were prepared employing Suzuki coupling and their properties were compared. A variation of the core nucleus from fluorene to carbazole was a key point to study its effect on the thermal, optical and electrochemical properties. The materials were characterized by FTIR, 1H-, 13C-NMR, APCI-MS and elemental microanalyses. The synthesized materials exhibit slightly bathochromic shifted UV/Vis spectra in dilute solution and emission maxima in the blue region along with good thermal stability. The dyes with a fluorene core are electrochemically and spectrally stable with high lying HOMO levels, in contrast to the carbazole only materials, having potential as light emitting and hole transporting materials in organic light emitting diodes.
High-efficiency red-light emission from polyfluorenes grafted with cyclometalated iridium complexes and charge transport moiety
Chen, Xiwen,Liao, Jin-Long,Liang, Yongmin,Ahmed,Tseng, Hao-En,Chen, Show-An
, p. 636 - 637 (2003)
We report a new route for the design of electroluminescent polymers by grafting high-efficiency phosphorescent organometallic complexes as dopants and charge transport moieties onto alky side chains of fully conjugated polymers for polymer light-emitting diodes (PLED) with single layer/single polymers. The polymer system studied involves polyfluorene (PF) as the base conjugated polymer, carbazole (Cz) as the charge transport moiety and a source for green emission by forming an electroplex with the PF main chain, and cyclometalated iridium (Ir) complexes as the phosphorescent dopant. Energy transfer from the green Ir complex or an electroplex formed between the fluorene main chain and side-chain carbazole moieties, in addition to that from the PF main chain, to the red Ir complex can significantly enhance the device performance, and a red light-emitting device with the high efficiency 2.8 cd/A at 7 V and 65 cd/m2, comparable to that of the same Ir complex-based OLED, and a broad-band light-emitting device containing blue, green, and red peaks (2.16 cd/A at 9 V) are obtained. Copyright
Does a cyclopropane ring enhance the electronic communication in dumbbell-type C60 dimers?
La Rosa, Andrea,Gillemot, Katalin,Leary, Edmund,Evangeli, Charalambos,González, María Teresa,Filippone, Salvatore,Rubio-Bollinger, Gabino,Agra?t, Nicolás,Lambert, Colin J.,Martín, Nazario
, p. 4871 - 4877 (2014)
Two C60 dumbbell molecules have been synthesized containing either cyclopropane or pyrrolidine rings connecting two fullerenes to a central fluorene core. A combination of spectroscopic techniques reveals that the cyclopropane dumbbell possesses better electronic communication between the fullerenes and the fluorene. This observation is underpinned by DFT transport calculations, which show that the cyclopropane dumbbell gives a higher calculated single-molecule conductance, a result of an energetically lower-lying LUMO level that extends deeper into the backbone. This strengthens the idea that cyclopropane behaves as a quasi-double bond.
Efficient design and structural modifications for tuning the photoelectric properties of small-molecule acceptors in organic solar cells
He, Xiaodong,Yin, Lunxiang,Li, Yanqin
, p. 6577 - 6586 (2019)
Five novel small molecules were designed and synthesized to investigate the relationships between molecular structures and photoelectric properties. Firstly, three A1-A-A1 type molecules, incorporating a 2,1,3-benzothiadiazole (BT) unit with no, one or two fluorine atoms as the core, 2-ethylhexyl-substituted phthalimide (PI) as the terminal moiety and ethynyl functionalized thiophene as the π-linker, were synthesized to explore the effect of fluorination on photoelectric properties, namely (PIAT)2BT, (PIAT)2fBT and (PIAT)2dfBT. By introducing fluorine atoms on the molecular backbone, both the HOMO and LUMO energy levels can be tuned efficiently, with minimal influence on optical absorption. Next, on the basis of the BT-based molecules, two extended molecules containing diketopyrrolopyrrole (DPP) were constructed, namely (PIAT)2DPP and FADPPPI, improving optical absorption successfully, especially for FADPPPI with an absorption edge of 850 nm in the film. Considering the photoelectric properties of the above five molecules, poly(3-hexylthiophene) (P3HT) was chosen as the electron donor material to pair with these molecules, and preliminary device fabrication and investigation of photovoltaic performances were performed. These results demonstrate that our materials show great potential in being small-molecule acceptors for organic solar cells (OSCs), and further research on device fabrication and optimization is in progress in our laboratory.
Unravelling the miniscule size effect of auxiliary donor in D-D-π-A type dipolar photosensitizers on quasi-solid state DSSC performance
Kumar, Chitra,Mohan, Ramesh,Praveen, Chandrasekar,Raheem, Abbasriyaludeen Abdul,Shanmugam, Ramasamy
, (2021)
Three new dipolar organic dyes of the type D-D-π-A were constructed on fluorenothiophene backbone by varying the terminal donor auxiliary such as -NMe2, -NEt2 and -NPh2. The effect of such structural variation on the photophysical and electrochemical properties has been investigated. Computational studies obtained from DFT/TD-DFT calculations were found to be in good correlation with the experimental optoelectronic results. TiO2 based n-type quasi-solid state DSSCs constructed on the synthesized dyes revealed a gradual increase in photovoltaic performance with increase in donor size. The trend in power conversion efficiency (η) was found to be -NPh2 (4.10%) > -NEt2 (3.44%) > -NMe2 (2.57%). Electrochemical impedence analysis also confirmed the longer electron life time for dye possessing bulky -NPh2 groups in comparision to -NEt2 and -NMe2 groups, thus demonstrating the impact of increased donor size on the DSSC performance. Overall, this paper validates the impact of donor size on the DSSC performance and could inspire the selection of appropriate auxiliary donors to enhance the efficiency in futuristic endeavors.
