- Photochromism of dihydroindolizines. Part XXIV: Exploiting “Click” chemistry strategy in the synthesis of fluorenyldihydroindolizines with multiaddressable photochromic properties
-
A new category of photochromic dihydroindolizines (DHIs) incorporating substituted 2,7- and 4-substituted tetrazole and oxadiazole moieties in the fluorene skeleton (region A) were efficiently prepared utilizing “Click” chemistry approaches. The structure elucidation for all synthesized precursors as well as the target photochromic DHIs was carried out using some analytical and spectroscopic techniques. A highly tunable photochromic behaviors of the parent dihydroindolizine are possible by the introduction of substituents in different positions of the DHI framework. For example, the substituents in 2,7 and 4-positions of fluorene part showed the ability for extending photochromism. The photochromic behaviors of photochromic DHIs substituted in fluorene part (region A) such as the reaction kinetics and fluorescence properties and their photo-fatigue resistance were studied. It has been disclosed that the replacement of the tetrazole moieties in 2,7-position in (region A) by oxadiazole moieties has strong effect on both the spectral, kinetic characteristics, fluorescence emission and photostability. The observations of this work imply that the substituent groups in the fluorene part influenced the thermal back-reaction rates and played an imperative role in controlling all photochromic properties of the open form. The new synthesized substituted (DHIs) in the fluorene by both tetrazole moieties in 2,7-position and by oxadiazole moieties in 2,7 and 4 positions in fluorene part made these materials act as fluorophores and postulate new opportunities for the design of the next generation of photochromic materials which will make it talented materials in many applications such as electronic smart materials, photochromic glasses, photonic devices and fluorescent fabrics. Because of their noticeable fluorescence emission high photostability, these materials can be used as fluorophores, recording or storage information for numerous periods without color fading.
- Ahmed, Saleh A.,El Guesmi, Nizar,Althagafi, Ismail I.,Khairou, Khalid S.,Altass, Hatem M.,Abdel-Wahab, Aboel-Magd A.,Asghar, Basim H.,Katouah, Hanadi A.,Abourehab, Mohamed A.S.
-
-
Read Online
- Synthesis and characterization of luminescent polyfluorenes incorporating side-chain-tethered polyhedral oligomeric silsesquioxane units
-
Using Suzuki polycondensation, we have synthesized polyhedral silseaquioxane-tethered polyfluorene copolymere, poly(9,9'-dioctylfluorene-co-9,9'-bis[4-(N,N-dipolysilsesquioxane)aminophenyl] -fluorene) (PFO - POSS), that have well-defined architectures. Th
- Chou, Chia-Hung,Hsu, So-Lin,Dinakaran,Chiu, Mao-Yuan,Wei, Kung-Hwa
-
-
Read Online
- Synthesis, Crystal Structure, and Catalytic Property of a Copper Coordination Compound Based on In Situ Generated 2-Hydroxynicotinic Acid
-
Abstract: The copper coordination complex [CuCl(2-OHNA)H2O]·H2O (1) was synthesized by the reaction of CuCl2·2H2O with in situ generated 2-hydroxynicotinic acid and its crystal structure was determined by single X-ray diffraction methods. It was further characterized by FT-IR spectroscopy, elemental analyses, and thermogravimetric analysis. Complex 1 crystallizes in monoclinic space group P21/c with a = 8.9797(13), b = 14.196(2), c = 7.0738(11) ?, β = 96.897(2), V = 895.2(2) ?3, Mr = 273.12, Dc = 2.027?g/cm3, and Z = 4. In the structure, complex 1 is linked into 2D sheets via intermolecular hydrogen bonding [N1–H1···O2 (?x+1, y ? 1/2, ? z+1/2); O5–H10···O2 (? x+1, y + 1/2, ? z+1/2); O4–H9···O5 (x, y ? 1, z); O4–H8···O5 (? x+2, y + 1, ? z)]. The catalytic property of 1 was also investigated in the selective oxidation of benzyl-alkanes using TBHP as oxidant. Under optimized conditions, 1 exhibited high catalytic activity and selectivity toward the corresponding aryl ketones. Graphic Abstract: The copper coordination complex [CuCl(2-OHNA)H2O]·H2O (1) was synthesized by the reaction of CuCl2·2H2O with in situ generated 2-hydroxynicotinic acid and the catalytic property of 1 was also investigated in the selective oxidation of benzyl-alkanes using TBHP as oxidant.[Figure not available: see fulltext.].
- Wu, Ren-Tao,Li, Ji-Kun,Wei, Chuan-Ping,Ma, Xian
-
-
Read Online
- Novel conjugated copolymers based on dithiafulvalene moiety for bulk heterojunction solar cells
-
New conjugated copolymers, P1-P3, based on dithiafulvalene-fused entity and different conjugated segments have been synthesized. Incorporation of electron-deficient conjugated segments into the conjugated copolymers results in red shifting the absorption
- Chen, Yung-Chung,Hsu, Chih-Yu,Lin, Jiann T.
-
-
Read Online
- Vice versa donor acceptor fluorene-ferrocene alternate copolymer: A twisted ribbon for electrical switching
-
Two donor-acceptor type copolymers (PFFC-1 and PFFC-2) containing ferrocene and fluorene moieties have been successfully synthesized to evaluate the redox triggered optical and electronic properties. Interestingly, PFFC-1 shows a twisted ribbon-like morphology at the liquid interface and switches to a micellar structure on oxidation.
- Chakraborty, Chanchal,Bera, Manas Kumar,Rana, Utpal,Malik, Sudip
-
-
Read Online
- Semiperfluoroalkyl polyfluorenes for orthogonal processing in fluorous solvents
-
The challenging synthesis of semiperfluoroalkyl polyfluorenes and characterization of their electro-optical properties has been reported. Solutions of conjugated polymers can be dispensed onto the desired area by inkjet printing or screen printing, or for
- Lee, Jin-Kyun,Fong, Hon Hang,Zakhidov, Alexander A.,McCluskey, Georgia E.,Taylor, Priscilla G.,Santiago-Berrios, MitK'El,Abruna, Hector D.,Holmes, Andrew B.,Malharas, George G.,Ober, Christopher K.
-
-
Read Online
- Highly efficient synthesis of 9-fluorenones from 9H-fluorenes by air oxidation
-
9-Fluorenones substituted with nitro, halogen, or alkyl groups can be easily obtained in high yield and purity by aerobic oxidation of 9H-fluorenes under ambient conditions in the presence of KOH in THF.
- Zhang, Xin,Ji, Xuan,Jiang, Shanshan,Liu, Lili,Weeks, Brandon L.,Zhang, Zhao
-
-
Read Online
- Monodentate Transient Directing Group Assisted Pd-Catalyzed Direct Dehydrogenative Cross-Coupling of Benzaldehydes with Arenes toward 9-Fluorenones
-
Commercially available 3,5-bis(trifluoromethyl)aniline was found to be a highly efficient monodentate transient directing group (MonoTDG) for the palladium-catalyzed direct dehydrogenative cross-coupling of benzaldehydes with arenes. A diverse set of symm
- Wang, Yi-Feng,Xu, Wen-Gang,Sun, Bing,Yu, Qin-Qin,Li, Tuan-Jie,Zhang, Fang-Lin
-
-
Read Online
- (E)-2,2'Dibromo-7,7'-bis(diphenylamino)-9,9'-bifluorenylidene as a new electron acceptor for organic photovoltaic cells
-
(E)-2,2'-Dibromo-7,7'-bis(diphenylamino)-9,9'-bifluorenylidene (BDPABF) was synthesized as a new non-fullerene-type electron acceptor for organic photovoltaic cells. The UV-visible absorption spectra of BDPABF showed two main bands at 319 and 474 nm in a
- Park, On You,Kim, Hee Un,Park, Jong Baek,Hwang, Do-Hoon
-
-
Read Online
- Four alkoxohexavanadate-based pd-polyoxovanadates as robust heterogeneous catalysts for oxidation of benzyl-alkanes
-
Four alkoxohexavanadate-based Pd-POVs [Pd(dpa)(acac)]2[V6O13(OMe)6] (1), [Pd(dpa)(acac)]2[V6O11(OMe)8] (2), [Pd(dpa)(acac)]2[V6O11(OMe)8]·H2O (3), and [Pd(DMAP)2(acac)]2[V6O11(OMe)8]·H2O (4) (POV = polyoxovanadate; dpa = 2,2′-dipyridine amine; DMAP = 4-dimethylaminopyridine; acac = acetylacetone anion) have been synthesized and fully characterized by single crystal X-ray diffraction and powder X-ray diffraction analyses, Fourier transform infrared spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In 1-4, Pd complexes and hexavanadate anions are assembled through electrostatic interactions. Interestingly, the [V6O11(OMe)8]2- cores in 2 and 3 are a pair of isomers that can be isolated by controlling crystallization temperature. Moreover, to the best of our knowledge, the {V6} core in 3 represents a new octamethoxyhexavanadates cluster. It is notable that compounds 1-4 exhibit excellent heterogeneous catalytic performance in the oxidation of benzyl-alkanes with t-butylhydroperoxide as oxidant. Among them, the catalytic activity of 1 (conv. and selec. up to 99%, respectively) outperforms others and can be reused without losing its activity.
- Li, Ji-Kun,Huang, Xian-Qiang,Yang, Song,Ma, Hong-Wei,Chi, Ying-Nan,Hu, Chang-Wen
-
-
Read Online
- Two 2-D multifunctional cobalt(ii) compounds: field-induced single-ion magnetism and catalytic oxidation of benzylic C-H bonds
-
Two cobalt(ii) compounds, namely, {[Co(HL)(bpy)(H2O)2]·DMF}n (1), and {[Co(HL)(bpe)]·0.5bpe}n (2) (H3L = 1,3-bis(2-carboxylphenoxy)benzoic acid, bpy = 4,4′-bipyridine, bpe = 4,4′-vinylenedipyridine), have been synthesized using cobalt(ii) transition metal salt with phenolic carboxylic acid and different N-donor ligands. The compounds were fully characterized by elemental analysis, infrared spectroscopy (IR), single crystal X-ray diffraction analysis, and thermogravimetric analysis (TGA). Both compounds exhibit 2-D (4,4)-sql networks but with a wavelike and a double layered arrangement, respectively. Remarkably, these two compounds not only exhibit field-induced single-ion relaxation magnetization but also exceptional catalytic activities of benzylic C-H oxidation (conv. 90.3-99%; sele. 98.1-99%).
- Ma, Ranran,Chen, Zhiwei,Cao, Fan,Wang, Suna,Huang, Xianqiang,Li, Yunwu,Lu, Jing,Li, Dacheng,Dou, Jianmin
-
-
Read Online
- Nonvolatile write-once read-many-times memory behaviors of polyimides containing tetraphenyl fluorene core and the pendant triphenylamine or carbazole moieties
-
To better understand the structure–property relationships, two novel aromatic diamines containing tetraphenyl fluorene (TPF) moiety through triphenylamine (TPA) unit and carbazole (Cz) unit modification are designed and synthesized, respectively. Four thermally stable and excellent solubility polyimides are prepared and characterized. The excellent film-formation ability and thin film stability are investigated by X-ray diffraction (XRD) and atom force microscopy (AFM) measurements, respectively. The memory devices are fabricated, PIs films with low water uptakes sandwiched between indium-tin oxide (ITO) ground electrode and Al top electrode, and exhibit nonvolatile write-once read-many-times (WORM) memory behaviors with low threshold voltages, due to increasing the retention time through regulating the energy level. The current conduction mechanisms of all devices are linearly fitted by theoretical conduction model. Molecular simulations are used to demonstrate switching mechanism and the memory effects. The experimental results provide a sight for the design-adjustable switching voltage of memory devices.
- Yang, Yanhua,Ding, Zijun,Xia, Jingcheng,Zheng, Youxuan,Ding, Shijin,Shen, Yingzhong
-
-
Read Online
- Amphiphilic ligands for Cu-catalyzed aerobic oxidation to synthesize 9-fluorenones in water
-
A series of amphiphilic PEG-functionalized nitrogen ligands were developed for the highly efficient copper-catalyzed aerobic oxidation of 9-fluorenes, with molecular oxygen as the sole oxidant in neat water. A broad range of functional groups are well tolerated and thus offer the opportunity for further functionalization.
- Li, Longjia,Liu, Zibo,Tang, Shanyu,Li, Jiao,Ren, Xuanhe,Yang, Guanyu,Li, Heng,Yuan, Bingxin
-
-
Read Online
- Coordination polymers based on substituted terpyridine ligands: synthesis, structural diversity, and highly efficient and selective catalytic oxidation of benzylic c-h bonds
-
Reaction of two related rigid terpyridine ligands, 4′-(4-cyanophenyl)-4,2′:6′,4-terpyridine (L1) and its derivative, 4′-(4-carboxyphenyl)-4,2′:6′,4-terpyridine (L2), with transition metal ions (Co2+ or Cu2+/Cu+), afforded four novel coordination compounds: Co(L1)Cl2 (1), Co3(L1)3Cl6 (2), CuI9(L1)4.5(CN)9 (3), and [CuII3(L2)6(H2O)6]·4H2O (4). Crystal structure analysis reveals that 1 is comprised of single-stranded 21 helical chains, and weak interactions involving C-H···Cl weak hydrogen bonding and stacking interactions exist in the structure. The structure of 2 is comprised of 32 helices, which is compared with the structure of compound 1. 3 shows a three-dimensional (3D) 4-fold interpenetration structure. 4 exhibits a one-dimensional gridlike belt structure, which further builds 3D supramolecular architecture via stacking interactions. These novel coordination compounds show exceptional catalytic activity for the oxidation of benzylic C-H bonds. Notably, compound 4 shows the best catalytic properties for the oxidation of benzylic hydrocarbons up to 99% conversion and 99% selectivity.
- Xi, Yaru,Wei, Wei,Xu, Yanqing,Huang, Xianqiang,Zhang, Fanzhou,Hu, Changwen
-
-
Read Online
- Mn(III) active site in hydrotalcite efficiently catalyzes the oxidation of alkylarenes with molecular oxygen
-
Developing efficient heterogeneous catalytic systems based on easily available materials and molecular oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni2Mn-LDH) has been found as an efficient catalyst in the oxidation of alkylarenes using molecular oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system have been observed. Mn3+ species was proposed to be the efficient active site, and Ni2+ played an important role in stabilizing the Mn3+ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni2Mn-LDH with the activation energy (Ea) and pre-exponential factor (A0) being 85.7 kJ mol?1 and 1.8 × 109 min?1, respectively. The Gibbs free energy (ΔG≠) was determined to be -10.4 kJ mol-1 K-1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by molecular oxygen and H2O or hydroxyl species, respectively, to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.
- Wang, Anwei,Zhou, WeiYou,Sun, Zhonghua,Zhang, Zhong,Zhang, Zhihui,He, MingYang,Chen, Qun
-
-
- Oxidative carbon-carbon bond cleavage of 1,2-diols to carboxylic acids/ketones by an inorganic-ligand supported iron catalyst
-
The carbon-carbon bond cleavage of 1,2-diols is an important chemical transformation. Although traditional stoichiometric and catalytic oxidation methods have been widely used for this transformation, an efficient and valuable method should be further explored from the views of reusable catalysts, less waste, and convenient procedures. Herein an inorganic-ligand supported iron catalyst (NH4)3[FeMo6O18(OH)6]·7H2O was described as a heterogeneous molecular catalyst in acetic acid for this transformation in which hydrogen peroxide was used as the terminal oxidant. Under the optimized reaction conditions, carbon-carbon bond cleavage of 1,2-diols could be achieved in almost all cases and carboxylic acids or ketones could be afforded with a high conversion rate and high selectivity. Furthermore, the catalytic system was used efficiently to degrade renewable biomass oleic acid. Mechanistic insights based on the observation of the possible intermediates and control experiments are presented.
- Chen, Weiming,Xie, Xin,Zhang, Jian,Qu, Jian,Luo, Can,Lai, Yaozhu,Jiang, Feng,Yu, Han,Wei, Yongge
-
supporting information
p. 9140 - 9146
(2021/11/23)
-
- Method for synthesizing fluorenone ketone compound through molecular oxygen oxidation in water phase
-
Aiming at the technical problems that in the prior art a method for synthesizing a fluorenone ketone compound has organic solvent pollution and byproducts can be generated, the invention provides a method for synthesizing a fluorenone ketone compound through molecular oxygen oxidation in a water phase. The method comprises the following steps: by taking a fluorenone compound as a substrate, dispersing into an alkali solution, and at 40-120 DEG C, in the presence of oxygen, and with a water-soluble transition metal compound as a catalyst, stirring to carry out reactions, thereby obtaining the fluorenone ketone compound. By adopting the method, molecular oxygen is adopted as an oxidant, and water is adopted as a solvent, so that an organic solvent is avoided, and the problem that multiple byproducts are generated because of peroxidation can be avoided.
- -
-
Paragraph 0054-0057
(2019/08/20)
-
- Photophysical properties and optical power limiting ability of Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at different positions
-
Two series of Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at different positions have been synthesized. In the absorption spectra, the Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 3,6-position have blue-shift with respect to the corresponding analogs bearing fluorene-type ligands with ethynyl units at 2,7-position, showing better transparency in the visible light region. Moreover, the Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 3,6-position show stronger triplet emission than corresponding analogs bearing fluorene-type ligands with ethynyl units at 2,7-position in the photoluminescent (PL) spectra. Furthermore, these Pt(II) polyynes were applied to optical power limiting (OPL) field. The Pt(II) polyynes bearing fluorene-type ligands with ethynyl units at 2,7-position show better OPL performance than the corresponding analogs with fluorene-type ligands of ethynyl units at 3,6-position. Therefore, changing the position of the ethynyl units in fluorene-type ligands can not only effectively control the photophysical properties of the Pt(II) polyynes, but also has an important effect on their OPL ability.
- Tian, Zhuanzhuan,Yang, Xiaolong,Liu, Boao,Zhong, Daokun,Zhou, Guijiang
-
supporting information
p. 28 - 36
(2019/06/05)
-
- Fluorenone-based organic gel molecule and preparation method and application thereof
-
The invention belongs to the technical field of gel materials and provides a fluorenone-based organic gel molecule and a preparation method and application thereof. A fluorescent sensing film preparedfrom the fluorenone-based organic gel molecules can be
- -
-
Paragraph 0136; 0154-0159; 0183; 0201-0206; 0219-0242
(2019/04/06)
-
- Control the self-assembly of fluorenone-based polycatenars by tuning chain length
-
Using Suzuki coupling reactions as key steps, a series of fluorenone-based polycatenars, consisting of a central 2,7-diphenyl-9-fluorenone core connected with the 3,4,5-trialkoxybenzoate unit via –COO- linkage at each side have been synthesized. Upon elon
- Zhao, Kai,Xiao, Yulong,Guo, Chunxiang,Chang, Qing,Gao, Hongfei,Cheng, Xiaohong
-
supporting information
p. 409 - 415
(2019/01/04)
-
- Transition-metal-free C(sp3)–H oxidation of diarylmethanes
-
An efficient direct C(sp3)–H oxidation of diarylmethanes has been demonstrated by this study. This method employs environment-friendly O2 as an oxidant and is promoted by commercially available MN(SiMe3)2 [M = K, Na or Li], which provides a facile method for the synthesis of various diaryl ketones in excellent yields. This protocol is metal-free, mild and compatible with a number of functional groups on substrates.
- Yang, Fan,Zhou, Bihui,Chen, Pu,Zou, Dong,Luo, Qiannan,Ren, Wenzhe,Li, Linlin,Fan, Limei,Li, Jie
-
-
- Electron Transfer around a Molecular Corner
-
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.
- Schmidt, Hauke C.,Larsen, Christopher B.,Wenger, Oliver S.
-
supporting information
p. 6696 - 6700
(2018/03/26)
-
- HIGH REFRACTIVE COMPOUND, INSULATING FILM, LIGHT EXTRACTING FILM, ORGANIC LIGHT EMITTING DIODE AND ORGANIC LIGHT DEVICE HAVING THE COMPOUND
-
The present invention relates to an organic compound and organic-inorganic hybrid particles which can be dissolved in a highly fluorinated solvent, and have a high refractive index. The organic compound of the present invention is represented by chemical formula 1. In chemical formula 1, Ar_1 and Ar_2 are each independently a C_5-C_30 arylene group or a C_4-C_30 heteroarylene group; R_1 and R_2 are each independently hydrogen, deuterium, tritium, a protecting group, or a vinyl group or an epoxy group which is directly connected or connected through a C_1-C_10 alkylene group; X is a halogen atom; a and b are each independently an integer of 0 to 4; and m and n are each independently an integer of 3 to 15. According to the present invention, the compound can prevent chemical infiltration with respect to organic matters although an insulating film pattern is formed adjacent to an organic matter layer composed of an organic light emitting diode since the compound can be dissolved in the highly fluorinated solvent. Particularly, since the compound has a high refractive index, the compound is patterned into a high refractive insulating film positioned adjacent to the organic light emitting diode such that the insulating film can be used as a material for a light extraction substrate. That is, insulating film patterns can be formed without causing chemical infiltration with respect to the organic matters by using the organic compound of the present invention, and the organic compound can be used in an insulating film requiring high refractive index properties. Therefore, the insulating film can be used as a film for light extraction of the organic light emitting diode by applying the compound of the present invention, and light emitting properties of an organic light emitting element and an organic light emitting device can be enhanced by improving light extraction efficiency of the organic light emitting element and the organic light emitting device to which the insulating films are applied.COPYRIGHT KIPO 2018
- -
-
Paragraph 0175; 0176; 0177
(2018/09/25)
-
- Synthesis and radiofluorination of novel fluoren-9-one based derivatives for the imaging of α7 nicotinic acetylcholine receptor with PET
-
By structure–activity relationship studies on the tilorone scaffold, the ‘one armed’ substituted dibenzothiophenes and the fluoren-9-ones were identified as the most potential α7 nAChR ligands. While the suitability of dibenzothiophene derivatives as PET tracers is recognized, the potential of fluoren-9-ones is insufficiently investigated. We herein report on a series of fluoren-9-one based derivatives targeting α7 nAChR with compounds 8a and 8c possessing the highest affinity and selectivity. Accordingly, with [18F]8a and [18F]8c we designed and initially evaluated the first fluoren-9-one derived α7 nAChR selective PET ligands. A future application of these radioligands is facilitated by the herein presented successful implementation of fully automated radiosynthesis.
- Teodoro, Rodrigo,Scheunemann, Matthias,Wenzel, Barbara,Peters, Dan,Deuther-Conrad, Winnie,Brust, Peter
-
supporting information
p. 1471 - 1475
(2018/04/10)
-
- Cu(II)-Catalyzed Ligand-Free Oxidation of Diarylmethanes and Second Alcohols in Water
-
We developed a simple and efficient Cu(II)-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% tert-butyl hydroperoxide (TBHP) in water. A series of diarylmethanes were directly oxidized into diaryl ketones in 67%–98% yields. Additionally, various secondary alcohols were also transformed into the desired products in 48%–98% yields. Importantly, the catalytic system in the absence of any organic solvent, surfactant, or phase transfer agent, had a wide substrate scope and a high tolerance for various functional groups.
- Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
-
supporting information
p. 1391 - 139
(2017/09/30)
-
- Bigger and Brighter Fluorenes: Facile π-Expansion, Brilliant Emission and Sensing of Nitroaromatics
-
π-Expanded butterfly-like 2D fluorenes and 3D spirobifluorenes 1–5 were synthesized via a DDQ-mediated oxidative cyclization strategy with a high regioselectivity. Through structural modification via π-expansion, it was possible to achieve near-ultraviolet absorption, bright-blue emission, very high near-unity fluorescence quantum yields in solution as well as in film states, and deep-lying HOMO energy levels with excellent thermal stabilities. Furthermore, these electron-rich compounds displayed a notable behavior towards sensing of nitroaromatic explosives, such as picric acid, up to a detection limit of 0.2 ppb.
- Ramakrishna, Jagarapu,Venkatakrishnan, Parthasarathy
-
supporting information
p. 181 - 189
(2017/02/05)
-
- Immobilization of Keggin polyoxovanadoniobate in crystalline solids to produce effective heterogeneous catalysts towards selective oxidation of benzyl-alkanes
-
Two ionic organic-inorganic hybrid compounds, [CuII(C2N2H8)2]4[CuII(C2N2H8)2(H2O)2]2[PNb12O40VVVIVO2]·(OH)2·11H2O (1) and [CoIII(C2N2H8)3]2[CoIII(C2N2H8)2(H2O)2]0.5[H2.5PNb12O40 VVVIVO2]·20H2O (2), based on P-centered dicapped polyoxoniobates and organometallic cations were isolated and structurally characterized by routine techniques. The trivalent cobalt complex-containing compound exhibits a looser arrangement compared with its divalent copper complex-containing counterpart, with a space volume of 34.9% for the former and 17.0% for the latter. The two compounds were proved to be effective in facilitating the oxidation of benzyl-alkanes to ketone products in a heterogeneous manner, evidencing the feasiblity of the strategy of self-immobilization of catalytically active, readily soluble PNb12O40(VO)2 species in crystalline solids.
- Hu, Jufang,Dong, Jing,Huang, Xianqiang,Chi, Yingnan,Lin, Zhengguo,Li, Jikun,Yang, Song,Ma, Hongwei,Hu, Changwen
-
p. 8245 - 8251
(2017/07/10)
-
- A simple, mild and efficient oxidation of benzylic alcohols in the presence of NBS/KOAc in aqueous solution
-
Background: The oxidation of benzylic alcohols to carbonyl compounds is a fundamental reaction in organic synthesis. In traditional oxidation processes, a large amount of toxic and volatile organic solvents and metal oxidants are used. Thus, developing environmentally benign oxidation processes is an important goal. N-Bromosuccinimide (NBS) is an inexpensive and convenient oxidant widely used in a variety of oxidative reactions under acidic or alkaline conditions. Methods: In this paper, we developed a simple, mild, and efficient oxidation of benzylic alcohols in the presence of N-bromosuccinimide (NBS)/KOAc in aqueous solution (H2O/CH2Cl2 = 3:1). Results: A series of benzylic alcohols were oxidized selectively to the corresponding ketones in moderate to excellent yields at room temperature. Conclusion: This reaction was carried out using a wide variety of substrates, required no metal catalyst, and proved to be tolerant towards a variety of different functional groups.
- Wu, Jianglong,Liu, Yan,Liu, Ping,Gu, Chengzhi
-
p. 254 - 260
(2017/07/15)
-
- Synthesis and Exciton Dynamics of Donor-Orthogonal Acceptor Conjugated Polymers: Reducing the Singlet-Triplet Energy Gap
-
The presence of energetically low-lying triplet states is a hallmark of organic semiconductors. Even though they present a wealth of interesting photophysical properties, these optically dark states significantly limit optoelectronic device performance. Recent advances in emissive charge-transfer molecules have pioneered routes to reduce the energy gap between triplets and "bright" singlets, allowing thermal population exchange between them and eliminating a significant loss channel in devices. In conjugated polymers, this gap has proved resistant to modification. Here, we introduce a general approach to reduce the singlet-triplet energy gap in fully conjugated polymers, using a donor-orthogonal acceptor motif to spatially separate electron and hole wave functions. This new generation of conjugated polymers allows for a greatly reduced exchange energy, enhancing triplet formation and enabling thermally activated delayed fluorescence. We find that the mechanisms of both processes are driven by excited-state mixing between π-πand charge-transfer states, affording new insight into reverse intersystem crossing.
- Freeman, David M. E.,Musser, Andrew J.,Frost, Jarvist M.,Stern, Hannah L.,Forster, Alexander K.,Fallon, Kealan J.,Rapidis, Alexandros G.,Cacialli, Franco,McCulloch, Iain,Clarke, Tracey M.,Friend, Richard H.,Bronstein, Hugo
-
supporting information
p. 11073 - 11080
(2017/08/21)
-
- Ionic liquid [bmim]Br assisted chemoselective benzylic [Formula presented] oxidations using tert-butyl hydroperoxide
-
A mild and efficient, ionic-liquid-assisted green protocol for the chemoselective oxygenation of benzylic C-H bonds to corresponding ketones using ionic liquid [bmim]Br with tert-butyl hydroperoxide has been developed. The method reported in this paper has the advantages of [bmim]Br acting as recyclable solvent and reagent. The usage of additives such as acids or bases and metal salts is not required. The developed strategy is further extended to oxidation of secondary alcohols to respective ketones under similar optimized reaction conditions.
- Naidu, Shivaji,Reddy, Sabbasani Rajasekhara
-
p. 441 - 445
(2016/07/27)
-
- Efficient and mild swern oxidation using a new sulfoxide and bis(trichloromethyl)carbonate
-
A new type of sulfoxide, 4-(2-(2-(methylsulfinyl) ethyl)-4-nitrophenyl)-morpholine (I), was designed and prepared in good yield. Upon the combination of I and bis(trichloromethyl)carbonate, the Swern oxidation of primary and secondary alcohols was significantly promoted under mild conditions, which afforded the corresponding aldehydes or ketones in good yields. It is noteworthy that the reoxidation of the isolated by-product sulfide V could be further recycled in Swern oxidation.
- Ye, Xiaojing,Fu, Hongliang,Ma, Jiahao,Zhong, Weihui
-
supporting information
p. 885 - 892
(2017/01/28)
-
- PL Quenching of Poly(3-hexylthiophene) by 2,2′,7,7′-Tetradiphenylamino-9,9′-Bifluorenylidene
-
2,2′,7,7′-Tetradiphenylamino-9,9′-bifluorenylidene, TDPABF, was synthesized by reductive dimerization using Lawesson's reagent. It is soluble in common organic solvents such as dichloromethane, chloroform, and 1,2-dichlorobenzene. Its synthesis was confir
- Park, On You,Kim, Hee Un,Hwang, Do-Hoon
-
p. 129 - 137
(2015/10/28)
-
- Novel tri-carbazole modified fluorene host material for highly efficient solution-processed blue and green electrophosphorescent devices
-
A series of novel solution-processable small-molecule host materials: 2DPF-TCz, 2SBF-TCz, 27DPF-TCz, and 27SBF-TCz comprising a fluorene monomer as the rigid core and tri-carbazole as the periphery have been designed and synthesized, and their optical, electrochemical, and thermal properties have been fully characterized. The host materials exhibit high glass-transition temperatures (231-310 °C) and high triplet energy levels (2.61-2.73 eV). High-quality amorphous thin films can be obtained by spin-coating the host materials from solutions. It is found that the HOMO level of the host materials can be tuned by linking the tri-carbazole unit to the 2,7 positions of the fluorine core, resulting in appropriate HOMO energy levels (-5.36 to -5.23 eV) for improved hole-injection in the device. Solution-processed blue and green electrophosphorescent devices bases on the developed host materials exhibit high efficiencies of 21.2 and 34.8 cd A-1, respectively.
- Tang, Jinan,Chen, Yuanshen,Cong, Lei,Lin, Baoping,Sun, Yueming
-
p. 3847 - 3853
(2014/06/09)
-
- Aerobic oxidation of 9H-fluorenes to 9-fluorenones using mono-/multilayer graphene-supported alkaline catalyst
-
The synthesis of 9-fluorenone derivatives has been achieved in high yield and with high purity by aerobic oxidation of 9H-fluorenes at room temperature in the presence of a graphene-supported KOH composite that acts as a catalyst in N,N-dimethylformamide. The new protocol involves very simple work-up procedures, and the solvent and the catalyst can be recycled and reused. A scaled-up preparative study employing this method was also conducted and showed its advantages of being both cost-effective and environmentally friendly, and has potential for application in industrial processes. Copyright
- Zhang, Xin,Ji, Xuan,Su, Ruifei,Weeks, Brandon L.,Zhang, Zhao,Deng, Songlu
-
p. 703 - 711
(2013/07/26)
-
- New fluorenone-containing organic photosensitizers for dye-sensitized solar cells
-
Four new organic dyes (F1-F4) comprising the triarylamine or fluorene unit as an electron-donating group, a less commonly used fluorenone spacer and a cyanoacrylic acid as the anchoring group in the molecular framework were synthesized, characterized and utilized in dye-sensitized solar cells (DSSCs). Their absorption, photoluminescence, electrochemical and photovoltaic properties were fully investigated in detail. Electrochemical data indicate that the tuning of the HOMO and LUMO energy levels can be conveniently accomplished by alternating the donor moiety. The photovoltaic performance can be increased by adding an electron-donating triarylamine or fluorene unit next to the fluorenone ring or increasing the number of thienyl ring next to the cyanoacrylic acid group, which is consistent with the results from electrochemical impedance spectroscopy. The maximal monochromatic incident photon-to-current conversion efficiency (IPCE) can reach up to 80% for DSSC devices based on F4 with the overall light to electricity conversion efficiency up to 4.71% (Voc = 565 mV, Jsc = 11.71 mA cm-2 and FF = 0.71) under AM 1.5 irradiation (100 mW cm-2).
- Lai, Lai-Fan,Qin, Chuanjiang,Chui, Chung-Hin,Islam, Ashraful,Han, Liyuan,Ho, Cheuk-Lam,Wong, Wai-Yeung
-
p. 428 - 436
(2013/07/27)
-
- Synthesis, properties and applications of biphenyl functionalized 9,9-bis(4-diphenylaminophenyl)fluorenes as bifunctional materials for organic electroluminescent devices
-
Four new bifunctional materials, namely BPTF, CBPTF, CMBPTF and BPVTF, having 9,9-bis(4-diphenylaminophenyl)fluorene as a molecular platform and biphenyl derivatives as end-capping substituents were synthesized and characterized. Their optimized structure
- Thangthong, A-Monrat,Prachumrak, Narid,Namuangruk, Supawadee,Jungsuttiwong, Siriporn,Keawin, Tinnagon,Sudyoadsuk, Taweesak,Promarak, Vinich
-
supporting information
p. 5263 - 5274
(2012/10/29)
-
- Synthesis, characterization, physical properties, and applications of highly fluorescent pyrene-functionalized 9,9-bis(4-diarylaminophenyl)fluorene in organic light-emitting diodes
-
A new, highly fluorescent pyrene-functionalized 9,9-bis(4- diarylaminophenyl)fluorene, namely PTF, was synthesized and characterized. This material is an amorphous molecular glass with notably high Tg, is electrochemically stable, and exhibits strong blue emission both in solution and solid state. It shows promising ability as a solution processed blue emitter and hole-transporter for OLEDs. High-efficiency sky-blue and Alq3-based green devices with luminance efficiencies of 1.13 and 4.08 cd/A are achieved, respectively. 2012 Elsevier Ltd. All rights reserved.
- Prachumrak, Narid,Thangthong, A-Monrat,Tarsang, Ruangchai,Keawin, Tinnagon,Jungsuttiwong, Siriporn,Sudyoadsuk, Taweesak,Promarak, Vinich
-
p. 5492 - 5496
(2012/11/07)
-
- Synthesis and photophysical properties of two-photon absorbing spirofluorene derivatives
-
New spirofluorene-based quadrupolar two-photon absorbing dyes having triphenylamine and N,Ndibutylaniline as electron donors at the end of molcules were designed and synthesized. The thirdorder nonlinear optical properties of these compounds were studied using a two-photon excited fluorescence method. They were found to have high two-photon absorption cross-section owing to extended conjugation of the spirofluorene moiety. The effect of varying the donor strength could be discerned by comparing the two compounds. They were successfully used as a photosensitizers for two-photon initiated polymerization of three-dimensional micro-objects. Copyright
- Lim, Jea-Geon,Prabhakaran, Prem,Park, Jin Sun,Son, Yong,Kim, Tae-Dong,Yang, Dong-Yol,Lee, Kwang-Sup
-
experimental part
p. 4403 - 4408
(2012/08/28)
-
- Synthesis and luminescent properties of block copolymers based on polyfluorene and polytriphenylamine
-
For the preparation of block copolymers containing polyfluorene (PF) and hole transporting segment, PF homopolymers with diphenylamine terminals were synthesized by Suzuki coupling polymerization. The terminals of PF were converted to polytriphenylamine (PTPA) block by C-N coupling polymerization to give PTPA-block-PF-block-PTPA (PF-PTPA) triblock copolymers with different PTPA chain lengths. These polymers were soluble in common organic solvents and readily formed thin films by solution processing. All of the polymers exhibited similar UV absorption and PL emission properties both in chloroform solution and in film state. PF-PTPA block copolymers showed relatively high HOMO compared with that of PF by cyclic voltammetry. Compared with corresponding PF homopolymers, the EL devices based on PF-PTPA block copolymers showed higher luminance and current efficiency than those of PF homopolymers because of the improvement of hole injection by the introduction of PTPA segment.
- Tan, Ying,Gu, Zhijie,Tsuchiya, Kousuke,Ogino, Kenji
-
experimental part
p. 1444 - 1452
(2012/06/29)
-
- A photo-degradable helix: Synthesis, structure, and photolysis of optically active poly[2,7-bis(4-t-butylphenyl)-9-methylfluoren-9-yl acrylate]
-
2,7-Bis(4-t-butylphenyl)-9-methylfluoren-9-yl acrylate (BBPMFA) was synthesized and polymerized using α,α′-azobisisobutyronitrile or n-Bu3B-air as a radical initiator and using the complex of 9-fluorenyllithium with (S)-(+)-1-(2-pyrrolidinylmet
- Sakamoto, Takeshi,Watanabe, Kento,Shichibu, Yukatsu,Konishi, Katsuaki,Sato, Shin-Ichiro,Nakano, Tamaki
-
scheme or table
p. 945 - 956
(2012/01/13)
-
- Arylamino-functionalized fluorene- and carbazole-based copolymers: Color-tuning their CdTe nanocrystal composites from red to white
-
Four alternating arylamino-functionalized copolymers were synthesized in a Suzuki copolymerization applying 4, 4′-(2,7-dibromo-9H-fluorene-9,9-diyl) dianiline, 4,4′-(2,7-dibromo-9H-fluorene-9,9-diyl)bis(N,N-diphenylaniline) , 4-(3,6-dibromo-9H- carbazol-9
- Kanelidis, Ioannis,Ren, Yi,Lesnyak, Vladimir,Gasse, Jan-Christoph,Frahm, Ronald,Eychmueller, Alexander,Holder, Elisabeth
-
experimental part
p. 392 - 402
(2012/01/06)
-
- PLANAR CONJUGATED COMPOUNDS AND THEIR APPLICATIONS FOR ORGANIC ELECTRONICS
-
The invention relates to organic semiconducting materials, methods for their preparation and organic electronic devices incorporating the said organic semiconducting materials. The organic semiconductors contain a compound of formula (I) Ar1=(Q
- -
-
Page/Page column 24-25
(2010/09/17)
-
- Sterically encumbered fluorene-based poly(arylene ether)s containing spiro-annulated substituents on the main chain
-
Two novel fluorene-based bisphenol monomers containing spiro-annulated substituents on the middle biphenylene moiety have been synthesized in this study. Through reacting with four 2-trifluoromethyl-activated bisfluoro monomers, two monomers were converted into a series of fluorene-based poly(arylene ether)s by nucleophilic displacement of the fluorine atoms on the terminal benzene ring of bisfluoro monomers. The obtained polymers exhibit weight-average molecular weight up to 2.41 × 105 g/mol in GPC. Thermal analysis studies indicated that these polymers did not show melting endotherms but did show ultrahigh Tg values up to 356 °C in DSC and outstanding thermal stability up to 643 °C for 5% weight loss in TGA under nitrogen atmosphere. The polymers are soluble in a wide range of organic solvents, THF, CHCl3, NMP, DMAc, DMF, toluene, etc., and are insoluble in DMSO and acetone at room temperature. Transparent and flexible films were easily prepared by solution casting from chloroform solution of each of the polymers.
- Huang, Wen Y.,Huang
-
experimental part
p. 10355 - 10365
(2011/09/13)
-
- 2,5-linked polyfluorenes for optoelectronic devices
-
Polyfluorene polymers and copolymers having substantial amounts (10-100%) of fluorenes coupled at the 2 and 5 positions of fluorene are useful as active layers in OLED devices where triplet energies >2.10 eV are required.
- -
-
Page/Page column 13
(2009/12/27)
-
- Improved, highly efficient, and green synthesis of bromofluorenones and nitrofluorenones in water
-
A series of bromo-, nitro-, and bromonitrofluorenones were synthesized chemo-and regioselectively in 90-98% yield via electrophilic aromatic bromination and nitration under mild conditions using water as the sole solvent. These synthetic methods involve simple workup procedures and use only minimal amounts of organic solvents during the purification of products. The newly developed methods have the advantages of being cost-effective and environmentally friendly and could potentially be used for the large-scale synthesis of fluorenone derivatives. Copyright Taylor & Francis Group, LLC.
- Zhang, Xin,Han, Jun-Bin,Li, Peng-Fei,Ji, Xuan,Zhang, Zhao
-
experimental part
p. 3804 - 3815
(2009/12/06)
-
- Simple and efficient method for obtaining fluorene and spirobifluorene bromide derivatives
-
A mild, simple, and efficient synthetic procedure for the preparation of 2-monobromo-, 2,7-dibromo-, and 2,2′,7,7′-tetrabromo-substituted spirobifluorene derivatives and their key intermediates, 2-monobromo- and 2,7-dibromo-substituted fluorene compounds, has been developed. The oxidative bromination of fluorene and spirobifluorene was achieved using NaBr/H2O2 as the bromine source. High conversion of the starting materials was achieved together with good selectivities under optimized reaction conditions. Copyright Taylor & Francis Group, LLC.
- Jiang, Wen-Feng,Wang, Hui-Long,Wang, An-Gang,Li, Zhe-Qi
-
p. 1888 - 1895
(2008/09/20)
-
- SPIROFLUORENE DERIVATIVE, MATERIAL FOR LIGHT-EMITTING ELEMENT, LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, AND ELECTRONIC DEVICE
-
It is an object of the present invention to provide a material having a high Tg and a wide energy gap. The present invention provides a spirofluorene derivative represented by General Formula 1. (In the formula, R1 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, or a group represented by General Formula 2. Each of R2 and R3 is either hydrogen or an alkyl group having 1 to 4 carbon atoms and may be identical or different. R4 is an aryl group having 6 to 15 carbon atoms. Each of R5 and R6 is any one of hydrogen, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 15 carbon atoms and may be identical or different.)
- -
-
Page/Page column 99
(2008/06/13)
-
- Synthesis of conjugated 2,7-bis(trimethylsilylethynyl)-(phenylethynyl) nfluoren-9-one and 9-(p-methoxyphenyl)-9-methyl derivatives: Optical properties
-
2,7-Substituted 9-fluorenones and 9,9-disubstituted fluorene have been synthesized and their fluorescence properties analyzed. The synthesis of conjugated 2,7-bis(trimethylsilylethynyl)-(phenylethynyl)nfluoren-9- one (or the 9-(p-methoxyphenyl)
- Rodríguez, J. Gonzalo,Tejedor, J. Luis,La Parra, Teresa,Díaz, Cristina
-
p. 3355 - 3361
(2007/10/03)
-
- Fluorescence enhancement of the water-soluble poly{1,4-phenylene-[9,9-bis- (4-phenoxybutylsulfonate)]fluorene-2,7-diyl} copolymer in n- dodecylpentaoxyethylene glycol ether micelles
-
The effect of the nonionic n-dodecylpentaoxyethylene glycol ether on the properties of the water-soluble poly {1,4-phenylene-[9,9-bis(4- phenoxybutylsulfonate)]fluorene-2,7-diyl} copolymer was discussed. It was observed that the aqueous solutions of PBS-PFP showed a broad absorption of around 381nm and a structured fluorescence. It was also found that the increases in the fluorescence quantum yield occurred in PBS-PFP on incorporation into C12E5 micelles. The incorporation of PBS-PFP into these structures may be important for sensor applications and could also produce structures such as columnar mesophases.
- Burrows,Lobo,Pina,Ramos,De Seixas Melo,Valente,Tapia,Pradhan,Scherf
-
p. 7425 - 7427
(2007/10/03)
-
- Production process of 2,7-dibromofluorenone
-
A process is provided for the production of 2,7-dibromofluorenone. According to the process, a 2,7-dibromofluorene-contianing raw material is oxidized with molecular oxygen in the presence of a phase transfer catalyst such as a quaternary ammonium salt in a heterogeneous, mixed solvent of an aqueous solution of a caustic alkali and a water-insoluble organic solvent. Crude crystals of 2,7-dibromofluorenone, which have been obtained by the oxidization, can be purified by recrystallization to recover 2,7-dibromofluorenone as crystals having a purity of at least 99 wt. %.
- -
-
-
