- Catalytic activities of NHC-PdCl2 species based on functionalized tetradentate imidazolium salt in three types of C-C coupling reactions
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A functionalized tetradentate imidazolium salt 9,10-bis{di[2′-(N-ethylimidazolium-1-yl)ethyl]aminomethyl}anthracene tetrakis(hexafluorophosphate) (1) has been synthesized and characterized. The catalytic activity of the NHC-PdCl2 species formed by compound 1 and PdCl2 was tested in Suzuki-Miyaura, Heck-Mizoroki and Sonogashira reactions. The results showed that this catalytic system was effective for above three types of C-C coupling reactions.
- Liu, Qing-Xiang,Zhao, Dong-Xue,Wu, Hao,Zhao, Zhi-Xiang,Lv, Shi-Zhen
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- Why triple bonds protect acenes from oxidation and decomposition
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An experimental and computational study on the impact of functional groups on the oxidation stability of higher acenes is presented. We synthesized anthracenes, tetracenes, and pentacenes with various substituents at the periphery, identified their photooxygenation products, and measured the kinetics. Furthermore, the products obtained from thermolysis and the kinetics of the thermolysis are investigated. Density functional theory is applied in order to predict reaction energies, frontier molecular orbital interactions, and radical stabilization energies. The combined results allow us to describe the mechanisms of the oxidations and the subsequent thermolysis. We found that the alkynyl group not only enhances the oxidation stability of acenes but also protects the resulting endoperoxides from thermal decomposition. Additionally, such substituents increase the regioselectivity of the photooxygenation of tetracenes and pentacenes. For the first time, we oxidized alkynylpentacenes by using chemically generated singlet oxygen (1O2) without irradiation and identified a 6,13-endoperoxide as the sole regioisomer. The bimolecular rate constant of this oxidation amounts to only 1 × 10 5 s-1 M-1. This unexpectedly slow reaction is a result of a physical deactivation of 1O2. In contrast to unsubstituted or aryl-substituted acenes, photooxygenation of alkynyl-substituted acenes proceeds most likely by a concerted mechanism, while the thermolysis is well explained by the formation of radical intermediates. Our results should be important for the future design of oxidation stable acene-based semiconductors.
- Fudickar, Werner,Linker, Torsten
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- PALLADIUM CATALYZED C-C COUPLING FOR SYNTHESIS OF pi -CONJUGATED POLYMERS COMPOSED OF ARYLENE AND ETHYNYLENE UNITS.
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Palladium compounds such as Pd(PPh//3)//4 and Pd(OAc)//2 catalyze polycondensation between dihalo aromatic compounds, X-Ar-X (Ar equals p-phenylene, 2,5-thiophenediyl, 9,10-anthracenediyl, 2,6-pyridinediyl, p-benzene-dicarbonyl, p-xylene- alpha , alpha prime -diyl), and acetylenic compounds (p-C//6H//4(C EQUVLNT CH)//2 or p-C//6H//4(C EQUVLNT CMgBr)//2). The polymers obtained have high thermal stabilities and most of them show fluorescence. One of the polymers is converted into semiconductors by doping with electron acceptors.
- Sanechika,Yamamoto,Yammoto
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- Synthesis and photophysical properties of 9,10-Bis(3-aryl-2-naphthyl)anthracenes
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The 9,10-bis(3-aryl-2-naphthyl)anthracenes 3 were prepared by the benzannulation reaction of 2-(phenylethynyl)benzaldehyde (1) and the corresponding 9,10-bis(arylethynyl)anthracenes 2 in the presence of Cu or Re catalyst and trichloroacetic acid. The photophysical properties of 3 in solutions were investigated.
- Umeda, Rui,Kimura, Masahiro,Tobe, Yoshito,Nishiyama, Yutaka
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- Palladium-Catalyzed Arylation of Polar Organometallics Mediated by 9-Methoxy-9-Borabicyclononane: Suzuki Reactions of Extended Scope
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An alternative way for performing Suzuki reactions is presented.The necessary borate is the actual nucleophile in these palladium catalyzed C-C-bond formations is prepared from 9-methoxy-9-borabicyclononane (9-OMe-9-BBN) and a polar organometallic reagent RM, and not as usually from a borane and a base.This approach allows cross couplings of aryl halides with e.g. alkynyl-, methyl-, or TMSCH2-groups, which were beyond the scope of the conventional Suzuki reaction.The method is highly chemoselective and turned out to be compatible with aldehyde-, amide-, ketone-, ester- and cyano functions as well as with basic nitrogen atoms in the substrates.It was applied to the synthesis of the acetylenic natural products junipal (9a) and eutypine methyl ether (10).Since 11B NMR studies revealed that the 9-OMe-9-BBN only serves as a shuttle for delivering the RM reagent but remains unchanged during the course of the reaction, it has been possible to device the first Suzuki-type reaction sub-stoichiometric in boron.This "catalytic" protocol was used to prepare compound 8 which is highly valuable for its chemoluminescence properties.
- Fuerstner, Alois,Seidel, Guenter
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- Luminescent assays for ketones and aldehydes employing catalytic signal amplification
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Herein we report the first use of transition metal catalytic signal enhancement for the analysis of small organic analytes. Two assays using Sonogashira and Suzuki cross-couplings have been used in the detection of ketones and aldehydes produce highly luminescent markers. The latter analysis utilizing the Suzuki coupling demonstrates the first use of peroxyoxalate initiated chemiluminescence in a sensing application. Chemiluminescent measurement revealed much higher sensitivity than fluorescence. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Houk, Ronald J. T.,Anslyn, Eric V.
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- Phenyleneanthracene derivatives as triplet energy acceptor/emitter in red light excitable triplet-triplet-annihilation upconversion
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A series of anthracene derivatives with 9,10-substituents were prepared as triplet acceptors/emitters for triplet-triplet-annihilation (TTA) upconversion. Different linkages of C[sbnd]C single bonds and C[tbnd]C triple bonds were used to tune the singlet and triplet state energy levels, which may enhance the TTA upconversion. The study of the photophysical properties of the compounds indicates that the C[sbnd]C linker does not alter the T1 state energy level substantially, whereas the C[tbnd]C linker significantly reduced the T1 state energy levels. With nanosecond transient absorption spectroscopy, the intermolecular triplet-triplet-energy-transfer (TTET) process was studied. The lack of the upconversion for some anthracene derivatives was attributed to the inappropriate T1 energy levels thus the lack of TTET. On the other hand, different upconversion quantum yields were observed for some acceptors, although the TTET processes are similar. This result is due to the different TTA. These studies will be useful for future development of the TTA upconversion and for study of the triplet state properties of organic chromophores.
- Zhong, Fangfang,Zhao, Jianzhang
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- Synthesis of N-Heterocyclic Carbine Silver(I) and Palladium(II) Complexes with Acylated Piperazine Linker and Catalytic Activity in Three Types of C—C Coupling Reactions
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Two bis-imidazolium salts LH2·Cl2 and LH2·(PF6)2 with acylated piperazine linker and two N-heterocyclic carbene (NHC) silver(I) and palladium(II) complexes [L2Ag2](PF6)2 (1) and [L2Pd2Cl4] (2) were prepared. The crystal structures of LH2·Cl2 and 1 were confirmed by X-ray analysis. In 1, one 26-membered macrometallocycle was generated through two silver(I) ions and two bidentate ligands L. The catalytic activity of 2 was investigated in Sonogashira, Heck-Mizoroki and Suzuki-Miyaura reactions. The results displayed that these C—C coupling reactions can be smoothly carried out under the catalysis of 2.
- Liu, Qingxiang,Zhang, Xiantao,Zhao, Zhixiang,Li, Xinying,Zhang, Wei
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supporting information
p. 605 - 613
(2021/02/01)
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- Synthesis, one/two-photon optical and electrochemical properties and the photopolymerization-sensitizing effect of anthracene-based dyes: Influence of the donor groups
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Four anthracene-based dyes (ANDs) with different donor groups, namely 9,10-bis(phenylethynyl)anthracene (A1), 9,10-bis((9-dodecyl-9H-carbazol-3-yl)ethynyl) anthracene (A2), 9,10-bis((10-dodecyl-10H-phenothiazin-3-yl)ethynyl)anthracene (A3), and 4,4′-(anthracene-9,10-diylbis(ethyne-2,1-diyl))bis(N,N-diphenylaniline) (A4) were synthesized and characterized. The ANDs showed considerable absorption in blue/green regions and strong fluorescence emission in the green to red region. Besides, the ANDs possess large two-photon absorption cross-sections at 780-880 nm. Electrochemical studies revealed that these electron donors possess different donating abilities which in turn influence the redox potential and excited intramolecular charge transfer intensity of the ANDs. The conjugation degree among the donor groups and anthracene also has a significant impact on the redox potential of the ANDs. Moreover, compounds A1, A2, and A3 are able to couple with iodonium salt to initiate radical photopolymerization under blue and green LED irradiation. In summary, the structure-property relationships were investigated in detail in this work, which may provide useful guidance for further research.
- Xue, Tanlong,Zhao, Di,Hao, Tingting,Li, Xiuyan,Wang, Tao,Nie, Jun
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p. 6737 - 6745
(2019/05/10)
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- Conjugated alkynyl anthracene derivative as well as preparation method and application thereof
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The invention discloses a conjugated alkynyl anthracene derivative. The structural formula of the conjugated alkynyl anthracene derivative is as shown in the description, wherein R1 and R2 are any oneof the following structural formulas; and R represents H or one of C1-C30 alkyl groups or one of C1-C30 alkoxy groups. The invention also discloses a preparation method and application of the conjugated alkynyl anthracene derivative. The conjugated alkynyl anthracene derivative has the advantages of being rigid in structure and stable in photochemical property.
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Paragraph 0029-0034
(2019/04/06)
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- Intermediates in the cleavage of endoperoxides
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The decomposition of anthracene endoperoxides has been investigated under various conditions. Thermolyses proceed via radical intermediates and afford anthracenes and rearrangement products, depending on the substitution pattern. Interestingly, not only the O–O but also the C–O bond can be cleaved homolytically. Under basic conditions fragmentations take place, affording anthraquinone, and reactive oxygen species. This mechanism explains the often observed decomposition of endoperoxides during work-up. Finally, an acid-catalyzed cleavage has been observed under release of hydrogen peroxide. The results should be interesting for the mechanistic understanding of peroxide decomposition and the endoperoxides might serve as mild sources of reactive oxygen species for future applications. Copyright
- Bauch, Marcel,Klaper, Matthias,Linker, Torsten
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supporting information
(2017/03/24)
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- Synthesis, structure and catalysis of a NHC-Pd(II) complex based on a tetradentate mixed ligand
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Bis-benzimidazolium salt (S)-2,2′-bis[2′′-(N-picolyl-benzimidazoliumyl)ethoxy]-1,1′-binaphthyl hexafluorophosphate [(S)-LH2]·(PF6)2 and its NHC palladium(ii) complex [(S)-LPd](PF6)2 (1) have been prepared and characterized. Complex 1 is formed by one tetradentate mixed ligand (S)-L and one Pd(ii) ion, in which one 15-membered ring and two 6-membered rings are present. In this complex, intramolecular π-π interactions between naphthalene rings and benzimidazole rings are observed. Additionally, the catalytic activity of complex 1 in three types of C-C coupling reactions (Suzuki-Miyaura, Heck-Mizoroki and Sonogashira reactions) was investigated. The results show that complex 1 is an effective catalyst in these coupling reactions.
- Liu, Qing-Xiang,Cai, Kang-Qing,Zhao, Zhi-Xiang
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p. 85568 - 85578
(2015/11/03)
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- Efficient synthesis of 9,10-bis(phenylethynyl)anthracene derivatives by integration of sonogashira coupling and double-elimination reactions
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9,10-Bis(phenylethynyl)anthracene (BPEA) derivatives were synthesized from 10-bromo-9-anthracenecarbaldehyde by stepwise Sonogashira coupling with phenylethynes and the one-shot double-elimination reaction with benzyl phenyl sulfones. Those two reactions could be integrated in a one-pot process to give unsymmetrically substituted BPEA derivatives in good yields by simple operations. This integrated process was applied to the synthesis of an extended BPEA derivative having an extra phenylethynyl group. The photophysical properties of the BPEA derivatives were investigated by UV/Vis and fluorescence spectroscopy. Georg Thieme Verlag Stuttgart · New York.
- Toyota, Shinji,Mamiya, Daiki,Yoshida, Rie,Tanaka, Ryo,Iwanaga, Tetsuo,Orita, Akihiro,Otera, Junzo
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p. 1060 - 1068
(2013/05/21)
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- Reversible photooxygenation of alkynylanthracenes: Chemical generation of singlet oxygen under very mild conditions
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In the dark and very fast: The generation of singlet oxygen ( 1O2) from endoperoxides, which are readily available by photooxygenation of the corresponding anthracenes, proceeds within minutes in the dark (see scheme), a rate hitherto unknown for other anthracenes or naphthalenes. This provides an efficient chemical source of singlet oxygen under very mild conditions.
- Fudickar, Werner,Linker, Torsten
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supporting information; experimental part
p. 13661 - 13664
(2012/01/06)
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- Palladium-catalyzed multialkynyl cross-coupling reactions with tetraalkynylindates
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An efficient Pd-catalyzed multialkynyl cross-coupling reaction performed with tetraalkyriylindates generated in situ from the reaction of 1 equiv. of indium trichloride with 4 equiv. of organometallic reagents has been developed to produce symmetric as well as unsymmetric multialkynyl-substituted aromatic compounds in good-to-excellent yields. In these reactions, the four acetylide groups in the tetraalkynylindates transferred effectively to a variety of aryl bromides.
- Kang, Dongjin,Eom, Dahan,Kim, Hyunseok,Lee, Phil Ho
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experimental part
p. 2330 - 2336
(2010/07/10)
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- De novo design for functional amorphous materials: Synthesis and thermal and light-emitting properties of Twisted anthracene-functionalized bimesitylenes
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The unique structural attributes inherent to D2dsymmetric rigid tetraarylbimesityls render their close packing in the solid state difficult. We have exploited the indisposed tendency of such modules based on the bimesityl scaffold toward crystallization to design a novel class of amorphous functional materials with high glass transition temperatures and thermal stability (T d > 400 °C). It is shown that a variety of 2- and 4-fold anthracene-functionalized bimesityls, 1-7, that exhibit excellent amorphous properties (Tg = ca. 190-330 °C) can be readily prepared via facile Pd(0)-mediated cross-coupling strategies. As the communication between the bimesityl core and the anchored anthracenes is negligible or only marginal, the trends observed for luminescence of model constituent anthracenes are reproduced in the condensed- phase photoluminescence and electroluminescence of 1-7. In other words, the emission characteristics, i.e., λmax and quantum yields, are readily modulated via appropriate modification of the fluorophores. The functional behavior of this unique class of amorphous materials based on the bimesityl scaffold is demonstrated by fabrication of OLED devices. The 2-fold functionalized derivatives 1 and 2 lend themselves to sublimation techniques, so that the electroluminescence is captured with high efficiencies at low turn-on voltages (3.5-6.5 V). The device ITO/NPB (400 A)/1% 2:MADN (400 A)/TPBI (400 A)/LiF (10 A)/AI (1500 A) for 2 yields the highest luminance of ～13 900 cd/m2 at 17.5 V, a maximum luminance efficiency of ～7.4 cd/A at 4.5 V, and a power efficiency of ～5.3 Im/W at 4.0 V. Further, at a brightness of 800 cd/m 2 and a current density of 13.8 mA/cm2, the device is found to exhibit excellent luminance efficiency of 5.8 cd/A, external quantum efficiency of 4.3% with a power efficiency of 2.2 Im/W, and pure blue light with a CIExy (x= 0.13, y= 0.18). The performance characteristics of the devices fabricated for 1 and 2 are remarkable. Although the 4-fold functionalized systems did not permit sublimation leading to spin-coating as a means for device fabrication, the observed electroluminescence for 4 and 5 attests to a broader scope and applicability of this new category of amorphous molecules for application in OLEDs.
- Moorthy, Jarugu Narasimha,Venkatakrishnan, Parthasarathy,Natarajan, Palani,Huang, Duo-Fong,Chow, Tahsin J.
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supporting information; scheme or table
p. 17320 - 17333
(2009/07/11)
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- A simple "palladium-free" synthesis of phenyleneethynylene-based molecular materials revisited
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Nucleophilic attack of acetylide anions at the two carbonyl moieties of para-quinones readily affords the corresponding diols. Subsequent reduction with stannous chloride affords a number of useful compounds, including 1,4-bis[(trimethylsilyl)ethynyl]benzene, 1,4-bis[(trimethylsilyl)ethynyl] naphthalene and 9,10-bis[(trimethylsilyl)ethynyl]anthracene. Sequential attack by different acetylide anions followed by reduction provides a useful route to differentially substituted compounds including 1-[(4-nonyloxyphenyl)ethynyl]-4- (phenylethynyl)benzene, a new luminescent liquid-crystalline material. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
- Lydon, Donocadh P.,Porres, Laurent,Beeby, Andrew,Marder, Todd B.,Low, Paul J.
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p. 972 - 976
(2007/10/03)
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- Use of the Pd-promoted Extended One-Pot (EOP) synthetic protocol for the modular construction of poly-(arylene ethynylene) co-polymers [-Ar-C≡C-Ar′-C≡C-]n, opto- and electro-responsive materials for advanced technology
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We report on the use of our novel multistep/ one-pot/Pd-promoted synthetic strategy, named extended one-pot (EOP), for the preparation of polymeric conjugated systems characterized by a backbone composed of regularly alternating alkyne and arylene moieties of type [-C≡C-A-C≡C-B-]n. The "A" unit (or module) is in charge of impressing mechanical strength, chemical stability and processability to the polymer, while different "B" units (or modules) have been selected to obtain polymers with different functional properties. With this "modular approach" concept, a series of co-poly(arylene ethynylene)s, of general formula [-Ar-C≡C-Ar′-C≡C-]n [Ar = 2,5-bis(octyloxy)benzene; Ar′ = 1,10-phenanthroline, hydroquinone, pyridine, tetrafluorobenzene, dithiophene, benzene, and anthracene] potentially useful for the fabrication of sensory, electroactive and light-emitting materials, have been formed. Investigations of the photophysical properties of these materials, both in solution and in the solid state, have demonstrated a large degree of variation of properties depending on the nature of Ar′ and the extension of the conjugation in the polymeric backbone. This EOP synthetic protocol, with its multiple and sequential one-pot Pd-catalyzed processes, is characterized by a very low catalyst charge loading, a consistent cut-down of reaction times, ease of operation and cost with respect to conventional procedures to obtain ethynylated polymers. Moreover, although it is based on the Pd-catalyzed coupling of organostannanes and aromatic halides (Stille reaction), the EOP synthetic route optimizes and reduces the use of tin, because during the multi-step one-pot process, tin intermediates are in situ formed by complete reconversion of tin by-products generated in the course of the transformation. In addition, after formation and isolation of polymeric materials, tin-containing products are recovered and reused to form new reagents for the delivery of the alkyne moiety into the polymer backbone.
- Micozzi, Alessandra,Ottaviani, Monica,Giardina, Giorgio,Ricci, Antonella,Pizzoferrato, Roberto,Ziller, Tiffany,Compagnone, Dario,Lo Sterzo, Claudio
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p. 143 - 160
(2007/10/03)
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- Fluorescence Studies of Poly(p-phenyleneethynylene)s: The Effect of Anthracene Substitution
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The poly(p-phenyleneethynylene) molecules, PI-PIII, synthesized by a palladium-catalyzed cross-coupling reaction of diiodobenzene derivatives and derivatives of 1,4-diethynylbenzene, are highly luminescent materials.The polymers are soluble by virtue of the -OC16H33 groups introduced on the aromatic rings and by controlling their molecular weight.The fluorescent quantum yields are between 0.35 and 0.40 depending on the material.The excited-state lifetimes of the polymers are 1-2 ns, slightly shorter than that of the model compund, 1,4-diphenylethynyl-2,5-dibutoxybenzene, which has a lifetime of 3 ns.Incorporation of anthracene, coupled at the 9,10-positions by using 9,10-dibromoanthracene, into the polymer backbone decreases the quantum yield to between 0.05 and 0.27 depending on the anthracene content.In addition, low-energy electronic transitions and longer wavelength emission bands associated with the anthracene group are produced.The polymers harvest optical energy and transfer it to the anthracene resulting in emission from this chromophore.In the case where only terminal anthracene units, introduced by using 9-bromo-10-phenylethynylanthracene, are present, the process is very efficient with >95percent of the energy being transferred to the end groups.
- Swager, Timothy M.,Gil, Caroline J.,Wrighton, Mark S.
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p. 4886 - 4893
(2007/10/02)
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- Synthesis and Absorption/Emission Spectroscopic Properties of Bis(phenylethynyl)benzenes and 9,10-Bis(phenylethynyl)anthracenes
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A series of bis(phenylethynyl)benzenes 3 and 9,10-bis(phenylethynyl)anthracenes 4 was synthesized by bromination-dehydrobromination reaction or newly developed direct triple bond formation reaction from styrylstilbenes 1 or distyrylanthracenes 2.Subsequently systematic investigations were carried out on their absorption and fluorescence spectra, and their chemiluminescence properties.The following points are apparent; (a) a linear relationship between and Hammett's ?P of compounds 3 and 4 was observed, (b) a significant relationship between Stokes' shift of 4 and ?P was observed and (c) in the series of compounds 4 the electron-donating ability of the substituents has a pronounced effect on the chemiluminescence properties.
- Nakatsuji, Shin'ichi,Matsuda, Kosei,Uesugi, Yukiko,Nakashima, Kenichiro,Akiyama, Shuzo,Fabian, Walter
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p. 755 - 758
(2007/10/02)
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- SYNTHESIS OF 9,10-DIACETYLENYLANTHRACENES
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Syntheses are reported for 9,10-bis(phenylethynyl)anthracene and its derivatives containing identical and different substituents in the phenyl groups by the acetylenic condensation of 9,10-dibromoanthracene.The introduction of a donor substituent into one phenyl group and a withdrawing substituent into the other leads to a significant shift of the fluorescence maximum toward longer wavelengths.
- Piskunov, A. V.,Moroz, A. A.,Shvartsberg, M. S
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p. 1303 - 1305
(2007/10/02)
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- Synthesis and Evaluation of Fluorescent Materials for Colour Control of Peroxyoxalate Chemiluminescence. I. The Phenylethynylation of Anthraquinone
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The synthesis of 9,10-bis(phenylethynyl)anthracene has been examined in detail prior to the synthesis of a series of phenylethynyl substituted aromatic compounds which are of interest as fluorescent materials for peroxyoxalate chemiluminescence.Reductions of the 9,10-bis(phenylethynyl)-9,10-dihydroanthracene-9,10-diol precursor by stannous chloride and by sodium hypophosphite-potassium iodide both gave a series of byproducts, in addition to 9,10-bis(phenylethynyl)anthracene.The formation of these compounds is interpreted in terms of a free-radical process.The interaction of 10-hydroxy-10-(phenylethynyl)anthrone with both the reducing systems has been rationalized and the reaction with concentrated sulfuric acid reinterpreted.
- Hanhela, Peter J.,Paul, D. Brenton
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p. 1669 - 1686
(2007/10/02)
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- Synthesis and Evaluation of Fluorescent Materials for Colour Control of Peroxyoxalate Chemiluminescence. III. Yellow and Red Fluorescent Emitters
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A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated.Fluorescence and chemiluminescence emission data for all compounds are presented.Both 2-chloro- and 6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet chemiluminescence with the peroxyoxalate system (λmax 609 and 614 nm respectively).Althgough solutions of both compounds decolorize slowly in the presence of air and light, when used in concentrations 0f 1-5*10-3 M they allow efficient chemiluminescence for greater than 5 h.
- Hanhela, Peter J.,Paul, Brenton D.
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p. 1701 - 1717
(2007/10/02)
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