- Synthesis and characterization of 5′-hexyl-2,2′-bithiophene based on organic dyes for dye-sensitized solar cell applications
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A series of new organic dyes, 2-(2,6-bis((E)-2-(5′-hexyl-2,2′-bithiophen-5-yl)vinyl)-pyran-4-ylidene)-2-cyanoacetic acid (OD-1) and 2,2′-(2-((E)-2-(5′-hexyl-2,2′-bithiophen-5-yl)vinyl)-1H-indene-1,3(2H)-diylidene)bis(2-cyanoacetic acid) (OD-2), were synthesized as a sensitizers for the application of dye-sensitized solar cells (DSSCs). The introduction of the 5′-hexyl-2,2′-bithiophene units as an electron donor group and 2,6-dimethyl-pyran-4-one or 1,3-indandione as a π-spacers units increased the conjugation length of the sensitizers and thus improved their molar absorption coefficient and light harvesting efficiency.
- Saravanan, Chinnusamy,Cho, Woosum,Kim, Yulhee,Jin, Sung-Ho,Gal, Yeong-Soon,Lee, Jae Wook
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Read Online
- Frequency and electric field controllable photodevice: FYTRONIX device
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Al/p-Si/BODIPY/Al diode was fabricated by forming BODIPY organic layer on p-Si having ohmic contact. The electrical and photoresponse properties of the prepared diode were investigated in detail. The current-voltage (I-V) measurements were performed under dark and various illumination intensities. It is observed that the photocurrent under illumination is higher than the dark current. The transient measurements indicate that the device exhibits both photodiode and photocapacitor behavior. We called this device as FYTRONIX device. The photoresponse behavior of the FYTRONIX device is controlled simultaneously by frequency and electric field. The FYRONIX device can be used as a photoresponse sensor in optoelectronic applications.
- Tataro?lu,Al-Sehemi, Abdullah G.,?zdemir, Mehmet,?zdemir, Resul,Usta, Hakan,Al-Ghamdi, Ahmed A.,Farooq,Yakuphanoglu
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Read Online
- Small-molecule semiconductors containing dithienylacrylonitrile for high-performance organic field-effect transistors
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We designed and synthesized four donor-acceptor-type conjugated small-molecule compounds DPP-CN-DTE-1, DPP-CN-DTE-2, DPP-DTE-CN-1 and DPP-DTE-CN-2. The four compounds contained long alkyl side chains on the diketopyrrolopyrrole acceptor unit and cyano (CN) groups substituted on the dithiophene ethylene donor unit at different positions. The four small molecules exhibited good thermal stability and solution dispersibility. The bottom gate-bottom contact OFET devices based on these compounds showed excellent p-type performances. The relationship between molecular structures and field-effect performances indicated that the alkyl side-chain length and the CN substituted position significantly affected their charge carrier transport properties. The DPP-CN-DTE-1 with side-chain 2-mercaptotetradecyl side-chains and inner-side substituted CN groups exhibited the highest hole mobility of 2.52 cm2 V-1 s-1. This work provided a promising approach to develop excellent p-type small-molecule semiconductors with high performance, good solution processability and thermal stability for device fabrications.
- Li, Dizao,Zou, Jiabin,Wei, Congyuan,Zhou, Yankai,Wang, Liping,Zhang, Weifeng,Yu, Gui
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- Cerium-photocatalyzed aerobic oxidation of benzylic alcohols to aldehydes and ketones
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We have developed a cerium-photocatalyzed aerobic oxidation of primary and secondary benzylic alcohols to aldehydes and ketones using inexpensive CeCl3 7H2O as photocatalyst and air oxygen as the terminal oxidant.
- K?nig, Burkhard,Kumar, Sumit,Stahl, Jessica,Yatham, Veera Reddy,Yedase, Girish Suresh
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supporting information
p. 1727 - 1732
(2021/08/05)
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- Direct bromodeboronation of arylboronic acids with CuBr2 in water
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An efficient and practical method has been developed for the preparation of aryl bromides via the direct bromodeboronation of arylboronic acids with CuBr2 in water. This strategy provides several advantages, such as being ligand-free, base-free, high yielding, and functional group tolerant.
- Tang, Yan-Ling,Xia, Xian-Song,Gao, Jin-Chun,Li, Min-Xin,Mao, Ze-Wei
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supporting information
(2021/01/05)
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- SUBSTITUTED 1H-IMIDAZO[4,5-B]PYRIDIN-2(3H)-ONES AND THEIR USE AS GLUN2B RECEPTOR MODULATORS
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Substituted 1 H-imidazo[4,5-b]pyridin-2(3H)-ones as NR2B receptor ligands. Such compounds may be used in NR2B receptor modulation and in pharmaceutical compositions and methods for the treatment of disease states, disorders, and conditions mediated by NR2B receptor activity.
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Page/Page column 134; 135
(2018/04/23)
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- Metal-free hypervalent iodine/TEMPO mediated oxidation of amines and mechanistic insight into the reaction pathways
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A highly efficient metal free approach for the oxidation of primary and secondary amines to their corresponding aldehydes and ketones using PhI(OAc)2 in combination with a catalytic amount of TEMPO as an oxidizing agent is described. This protocol is rapid and provides diverse products under milder reaction conditions in excellent yields. In addition, the mechanistic study is well demonstrated by spectroscopic methods.
- Bansode, Ajay H.,Suryavanshi, Gurunath
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p. 32055 - 32062
(2018/09/29)
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- Chemoselective hydrogen peroxide oxidation of primary alcohols to aldehydes by a water-soluble and reusable iron(iii) catalyst in pure water at room temperature
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Hydrogen peroxide oxidation of primary alcohols to aldehydes is described, which is catalyzed by a novel, reusable and water-soluble FeCl3 complex in situ-formed with quaternary ammonium salt-functionalized 8-aminoquinoline. This reaction exhibits unique chemoselectivity and broad functional-group tolerance, and it can operate efficiently in pure water at room temperature.
- Yan, Qi,Fang, Ye Chen,Jia, Yun Xue,Duan, Xin Hong
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p. 2372 - 2377
(2017/03/21)
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- Method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing alkyl aromatic compound by iron
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The invention discloses a method for synthesizing aromatic aldehyde, aromatic ketone and aromatic ester through catalytically oxidizing an alkyl aromatic compound by iron, and belongs to the technical field of catalytic synthesis. According to the method, a low-cost and environment-friendly iron catalyst is used under a normal pressure; under the action of hydrogen and silicon reagents serving as an accelerant and an oxidant, a side chain of an aromatic hydrocarbon is oxidized into a carbonyl group for generating the corresponding aromatic aldehyde, aromatic ketone and aromatic ester. The method for preparing the aromatic aldehyde, the aromatic ketone and the aromatic ester through a catalytic oxidation reaction, which is provided by the invention, has numerous advantages that a catalyst, reaction raw materials, the oxidant and a silicon reagent are wide in sources and good in stability and is low-cost and environment-friendly; the alkyl aromatic compound is metered to participate in a reaction; the reaction condition is mild; the compatibility of functional groups is good; the scope of application is wide; the reaction selectivity is good; in an optimized reaction condition, the separation yield of a target product can be up to approximately 95 percent.
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Paragraph 0032; 0034
(2017/10/13)
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- Candida parapsilosis ATCC 7330 mediated oxidation of aromatic (activated) primary alcohols to aldehydes
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A green, simple and high yielding [up to 86% yield] procedure is developed for the oxidation of aromatic (activated) primary alcohols to aldehydes using whole cells of Candida parapsilosis ATCC 7330. The biotransformation is carried out under mild conditions at 25 °C, in hexane: water (48 : 2) (v/v).
- Sivakumari, Thakkellapati,Chadha, Anju
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p. 91594 - 91600
(2015/11/10)
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- A molecular breakwater-like tetrapod for organic solar cells
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We report the synthesis and characterization of a tetrapodal breakwater-like small molecule, SO, containing a tetraphenylsilane core and four cyanoester functionalized terthiophene arms. SO possesses a deep lying HOMO energy level of -5.2 eV and a narrow bandgap of 1.9 eV. Absorption, X-ray scattering and differential scanning calorimetry (DSC) measurements indicate crystalline nature of this compound but very slow crystallization kinetics. Solar cells employing SO and phenyl-C61-butyric acid methyl ester (PCBM) were fabricated and evaluated. Relatively low performance was obtained mainly due to the lack of optimal phase separation under various processing conditions including thermal annealing, slow-cooling and solvent annealing. Addition of poly(thienylene vinylene) (PTV), poly(3-hexylthiophene) (P3HT) and a platinum-containing low bandgap conjugated polymer Pt-BODIPY, into the SO/PCBM blend was found to induce device favorable phase separation and the polymers were found to act as the primary hole conductor. Such ternary blend devices showed cooperatively improved performances over binary devices employing either SO or the individual conjugated polymer alone.
- Yang, Jianzhong,He, Wenhan,Denman, Kimberly,Jiang, Ying-Bing,Qin, Yang
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p. 2108 - 2119
(2015/02/05)
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- D-π-A structured porphyrins for efficient dye-sensitized solar cells
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In this study, new push-pull alkoxy-wrapped zinc porphyrin dyes with intramolecular donor-π-acceptor structures have been designed and synthesized for dye-sensitized solar cells (DSCs). The linkers based on thiophene or 2,3-dihydrothieno[3,4-b][1,4] dioxine with cyanoacetic acid can broaden the spectral response of porphyrins into the near-IR region (～850 nm), which is mainly attributed to the cyanoacetic acid group. However, porphyrins with cyanoacrylic acid as an anchoring group lead to a faster charge recombination rate at the dye-sensitized heterojunction interface, which lowers the device photovoltaic performance. By using porphyrins with a rigid π-linker feature structure that is 5-ethynylthiophene-2-carboxylic acid, highly efficient DSC devices with a power conversion efficiency of 9.5% can be obtained. Spectral, electrochemical, photovoltage transient decay and impedance measurements are performed to reveal the influence of π-conjugated linkers and anchoring groups upon the optoelectronic features of porphyrin dyes in DSCs.
- Lu, Jianfeng,Xu, Xiaobao,Cao, Kun,Cui, Jin,Zhang, Yibo,Shen, Yan,Shi, Xiaobo,Liao, Liangsheng,Cheng, Yibing,Wang, Mingkui
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supporting information
p. 10008 - 10015
(2013/09/02)
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- Modified McFadyen-Stevens reaction for a versatile synthesis of aliphatic/aromatic aldehydes: Design, optimization, and mechanistic investigations
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The traditional McFadyen-Stevens reaction requires harsh alkaline reaction conditions, thus precluding application to the synthesis of aliphatic aldehydes. Our modified McFadyen-Stevens reaction enables the transformation from the N,N-acylsulfonyl hydrazine to the corresponding aldehyde upon treatment with an imidazole-TMS imidazole combination without relying on oxidative or reductive reagents. The reduced basicity and in situ protection of the resulting aldehyde widens the substrate scope to include aliphatic aldehydes, even ones bearing an α-hydrogen atom. Close examination of the side reactions for particular substrates in combination with theoretical considerations via DFT calculations led to a mechanistic understanding of the McFadyen-Stevens reaction involving an acyl diazene and a hydroxy carbene as reasonable intermediates.
- Iwai, Yuri,Ozaki, Takashi,Takita, Ryo,Uchiyama, Masanobu,Shimokawa, Jun,Fukuyama, Tohru
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p. 1111 - 1119
(2013/06/04)
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- Macrocyclic triphenylamine based organic dyes for efficient dye-sensitized solar cells
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A novel class of organic D-π-A dyes employing macrocyclic triphenylamine dimer as electron donor was designed and synthesized for dye-sensitized solar cells. The prepared compounds showed high chemical and elelctrochemical stabilities as well as good long-wave absorption. Photovoltaic devices based on these dyes showed high open circuit voltage (higher than that of N3) and achieved a solar energy to electricity conversion efficiency of 6.31%. All the performances indicate the dyes containing macrocyclic triphenylamine dimer is a good candidate for dyes sensitized solar cells.
- Zhao, Yun,Jiang, Kejian,Xu, Wei,Zhu, Daoben
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p. 9113 - 9118
(2012/10/30)
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- Chemistry of polyhalogenated nitrobutadienes, part 11: Ipso-formylation of 2-chlorothiophenes under Vilsmeier-Haack conditions
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The regioselective ipso-formylation of electron-rich, 3,4-push-pull- substituted 2-chlorothiophenes under Vilsmeier-Haack conditions was performed in good yields. The synthetic scope of this new reaction was explored using various halothiophenes, chloroanilines, and 1-methyl-3-chloroindole. In comparison with their structural C-H analogs the chlorinated thiophenes, anilines, and the indole proved to be less reactive toward electrophilic attack by chloromethyleniminium salts.
- Vogt, Eva-Janina,Zapol'skii, Viktor A.,Nutz, Eva,Kaufmann, Dieter E.
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experimental part
p. 285 - 294
(2012/07/14)
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- Application of flow chemistry to the selective reduction of esters to aldehydes
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The reduction of esters to aldehydes is an important transformation in organic chemistry and several reducing agents have been described. However, the use of this reaction in medicinal and natural product chemistry is limited due to the instability of the intermediates and the high reactivity of the reaction products. In the current article, the general and selective reduction of esters with diisobutyl-tert-butoxyaluminum hydride in flow is reported. This reagent allows esters to be reduced in the presence of different functional groups, including those considered to be of similar or higher reactivity. Copyright
- De Munoz, Juan M.,Alcazar, Jesus,De La Hoz, Antonio,Diaz-Ortiz, Angel
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supporting information; experimental part
p. 260 - 263
(2012/02/16)
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- Synthesis and photovoltaic properties of new metalloporphyrin-containing polyplatinyne polymers
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Three new solution-processable platinum(II) polyyne polymers containing zinc(II) porphyrinate chromophores P1, P2, and P3 and their corresponding dinuclear model complexes were synthesized via the CuI-catalyzed dehydrohalogenation reaction of the platinum(II) chloride precursor and each of the respective bis(ethynyl)-zinc(porphyrin) metalloligands. The thermal, photophysical (absorption, excitation and emission spectra), electrochemical, and photovoltaic properties of P1-P3 were investigated. These results are also correlated by time-dependent density functional theory (TDDFT) calculations. The computations corroborate the presence of moderate conjugation in the π-systems, somewhat more accentuated for P3 where more favorable dihedral angles between the porphyrin and thiophene rings are noted. Moreover, the computed excited states are predicted to be π-π* in nature with some charge transfer components from the trans-[-C≡CPt(L)2C≡ C-]n unit to the porphyrin rings. The optical bandgaps range from 1.93 to 2.02 eV for P1-P3. Intense π-π*-localized fluorescence emissions typical of the Q-bands of the polymers were observed. The effect of thiophene ring along the polymer chain on the extent of π-conjugation, luminescent and photovoltaic properties of these metalated materials was also examined. Bulk heterojunction solar cells using these metallopolymers as an electron donor blended with a methanofullerene electron acceptor were studied. In one case, the metallopolymer P3 showed a power conversion efficiency of 1.04% with the open-circuit voltage of 0.77 V, short-circuit current density of 3.42 mA cm-2 and fill factor of 0.39 under illumination of an AM 1.5 solar cell simulator.
- Zhan, Hongmei,Lamare, Simon,Ng, Annie,Kenny, Tommy,Guernon, Hannah,Chan, Wai-Kin,Djurisic, Aleksandra B.,Harvey, Pierre D.,Wong, Wai-Yeung
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scheme or table
p. 5155 - 5167
(2012/04/17)
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- Aerobic oxidation of benzylic halides to carbonyl compounds with molecular oxygen catalyzed by tempo/kno2 in aqueous media
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Benzylic halides were successfully oxidized to the corresponding aldehydes and ketones in good to excellent yields in aqueous media with molecular oxygen as oxidant in the presence of catalytic amounts of TEMPO (2,2,6,6- tetramethylpiperidyl-1-oxy) and potassium nitrite (KNO2).
- Liu, Qifa,Lu, Ming,Yang, Fei,Wei, Wei,Sun, Feng,Yang, Zhenbang,Huang, Sufeng
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scheme or table
p. 1106 - 1114
(2010/04/29)
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- Thiophene-linked porphyrin derivatives for dye-sensitized solar cells
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Three novel organic dyes based on porphyrin derivatives were designed and synthesized for dye-sensitized solar cells, resulting in a maximum power conversion efficiency (η) of 5.14% and a maximum IPCE value of 72% for a cell based on the PZn-hT dye. The Royal Society of Chemistry 2009.
- Liu, Yijiang,Xiang, Na,Feng, Xiaoming,Shen, Ping,Zhou, Weiping,Weng, Chao,Zhao, Bin,Tan, Songting
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supporting information; experimental part
p. 2499 - 2501
(2009/09/30)
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- Near-infrared fluorophores containing benzo[c]heterocycle subunits
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(Chemical Equation Presented) The syntheses and spectroscopic properties of eight new push-pull-type near-infrared fluorophores that contain either isobenzofuran or isothianaphthene subunits are presented. The isobenzofuran dyes demonstrate significantly red-shifted absorption compared with their isothianaphthene counterparts, which is attributed to isobenzofuran's more potent pro-quinoidal character.
- Meek, Scott T.,Nesterov, Evgueni E.,Swager, Timothy M.
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supporting information; experimental part
p. 2991 - 2993
(2009/05/07)
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- Synthesis and properties of novel second-order NLO chromophores containing pyrrole as an auxiliary electron donor
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A novel series of second-order NLO chromophores containing pyrrole as an auxiliary electron donor was synthesized via Knoevenagel reactions between 5-aminated N-methylpyrrole-2-carbaldehydes and different electron-accepting groups, i.e., malononitrile, picolinium tosylate and 2-dicyanomethylene-3-cyano- 4,5,5-trimethyl-2,5-dihydrofuran (TCF). Their corresponding NLO chromophores containing thiophene in the place of pyrrole were also prepared for comparison. The resulting NLO chromophores showed good solubility in common organic solvents such as CHCl3, THF and DMF, except for TTCF containing thiophene and TCF, which is soluble in polar aprotic solvents but poorly soluble in less polar solvents. NMR studies of these chromophores showed that, in comparison with thiophene rings in the same type of NLO chromophores, pyrrole rings had higher electron density, as evidenced by the up-field chemical shifts of pyrrole protons. TGA investigations showed good thermal stability of these chromophores in nitrogen with the onset weight loss temperatures in the range of 203 to 296 °C. Positive solvatochromism of 10-44 nm from dioxane to chloroform were found for these chromophores, and moderate to very large molecular static hyperpolarizabilities (β0) of 57-1490 × 10-30 esu were revealed by hyper-Rayleigh scattering measurements. For chemical bonding to polymer chains, hydroxyl-containing NLO chromophores were also prepared and characterized for their linear and nonlinear optical properties. The Royal Society of Chemistry 2008.
- Ma, Xiaohua,Liang, Ran,Yang, Fan,Zhao, Zhenhua,Zhang, Aixin,Song, Naiheng,Zhou, Qifeng,Zhang, Jianping
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scheme or table
p. 1756 - 1764
(2009/09/06)
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- Synthesis and nonlinear optical absorption properties of two new conjugated ferrocene-bridge-pyridinium compounds
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Two electron donor-π-acceptor (D-π-A) chromospheres, with ferrocene as the electron donor and pyridinium as the electron acceptor, were synthesized. The nonlinear optical absorption (NOA) properties in the solution state were investigated by the Z-scan technique. Both compounds exhibited reverse saturable absorption (RSA) and optical limiting effect under nanosecond pulse irradiation.
- Yang, Fan,Xu, Xiu-Ling,Gong, Yong-Hua,Qiu, Wen-Wei,Sun, Zhen-Rong,Zhou, Jin-Wei,Audebert, Pierre,Tang, Jie
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p. 9188 - 9194
(2008/02/10)
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- One-pot synthesis of ω-bromoesters from aromatic aldehydes and diols using pyridinium hydrobromide perbromide
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A simple and efficient one-pot procedure has been developed for the synthesis of ω-bromoesters from aromatic aldehydes and diols in the presence of pyridinium hydrobromide perbromide (PHPB) and triethoxymethane in which aldehyde reacts first with diol and the product, cyclic acetal, reacts with PHPB to give the final product, ω-bromoesters.
- Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
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p. 1989 - 1992
(2007/10/03)
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- Integrin expression inhibitors
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The present invention provides an integrin expression inhibitor, and an agent for treating arterial sclerosis, psoriasis, cancer, retinal angiogenesis, diabetic retinopathy or inflammatory diseases, an anticoagulant, or a cancer metastasis suppressor on the basis of an integrin inhibitory action. Namely, it provides an integrin expression inhibitor comprising, as an active ingredient, a sulfonamide compound represented by the following formula (I), a pharmacologically acceptable salt thereof or a hydrate of them. In the formula, B means a C6-C10 aryl ring or 6- to 10-membered heteroaryl ring which may have a substituent and in which a part of the ring may be saturated; K means a single bond, —CH═CH— or —(CR4bR5b)mb— (wherein R4b and R5b are the same as or different from each other and each means hydrogen atom or a C1-C4 alkyl group; and mb means an integer of 1 or 2); R1 means hydrogen atom or a C1-C6 alkyl group; Z means a single bond or —CO—NH—; and R means a C6-C10 aryl ring or 6- to 10-membered heteroaryl ring which may have a substituent and in which a part of the ring may be saturated, respectively.
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- Transition-Metal-Free: A Highly Efficient Catalytic Aerobic Alcohol Oxidation Process
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A highly efficient catalytic system without transition metals has been developed for aerobic alcohol oxidations. Under the optimal reaction conditions, various alcohol substrates were converted into their corresponding carbonyl compounds by air with TEMPO/Br2/NaNO2 as catalyst, especially the oxidation of benzylic alcohols to benzaldehydes in high yields. Copyright
- Liu, Renhua,Liang, Xinmiao,Dong, Chunyan,Hu, Xinquan
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p. 4112 - 4113
(2007/10/03)
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- Method of converting functional group through halogen-metal exchange reaction
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A method by which a halogen atom of a halogen compound can be efficiently replaced with an electrophilic group. Also provided are: a reagent for converting a functional group through a halogen-metal exchange reaction, characterized by comprising either a mixture of a magnesium compound represented by the formula R1—Mg—X (I) (wherein R1 represents a halogen atom or an optionally substituted hydrocarbon residue; and X1 represents a halogen atom) and an organolithium compound represented by the formula R2—Li (II) (wherein R2 represents an optionally substituted hydrocarbon residue) or a product of the reaction of the magnesium compound with the organolithium compound; and a process for producing with the reagent a compound in which a halogen atom of a halogen compound has been replaced with an electrophilic group.
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- INTEGRIN EXPRESSION INHIBITORS
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The present invention provides an integrin expression inhibitor, and an agent for treating arterial sclerosis, psoriasis, cancer, retinal angiogenesis, diabetic retinopathy or inflammatory diseases, an anticoagulant, or a cancer metastasis suppressor on the basis of an integrin inhibitory action. Namely, it provides an integrin expression inhibitor comprising, as an active ingredient, a sulfonamide compound represented by the following formula (I), a pharmacologically acceptable salt thereof or a hydrate of them. In the formula, B means a C6-C10 aryl ring or 6- to 10-membered heteroaryl ring which may have a substituent and in which a part of the ring may be saturated; K means a single bond, -CH=CH- or - (CR4bR5b)mb- (wherein R4b and R5b are the same as or different from each other and each means hydrogen atom or a C1-C4 alkyl group; and mb means an integer of 1 or 2); R1 means hydrogen atom or a C1-C6 alkyl group; Z means a single bond or -CO-NH-; and R means a C6-C10 aryl ring or 6- to 10-membered heteroaryl ring which may have a substituent and in which a part of the ring may be saturated, respectively.
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- Influence of solvent polarity and viscosity on nonradiative processes in oligothiophenes with intramolecular charge transfer
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By the methods of luminescence, picosecond spectroscopy, and quantum-chemical calculations the mechanisms of electron excitation energy deactivation in some oligothiophenes with intramolecular charge transfer depending on the solvent polarity and viscosity have been investigated. While for 2-N-piperidino-5-(2',2'-dicyanovinyl)thiophene (PDCVT) the main channel of nonradiative deactivation is the transition to a lower intermediate state with a "twisted" double bond controlled by the medium viscosity, in the case of (E)-{2-[2-5-piperidino-2-thienyl]-6-(triftuoridemethyl)-4H-4-pyranylidene}propanedinitryl (PTFDN) fluorescence quenching is initiated by the solvent polarity. For two other oligothiophenes, 2-N-piperidino-5-cyanothiophene (PCT) and 2-N-piperidino-5"-cyanoterthiophene (PCTT), differing in the length of the thiophene chain, we have revealed, along with the effective quenching of fluorescence in short-chain PCT (independent of the solvent polarity and viscosity), an increase in the radiation capacity in PCTT with increasing polarity of the solvent. The possible mechanisms of nonradiative deactivation in the investigated oligothiophenes are discussed.
- Bondarev, S. L.,Knvukshto, V. N.,Tikhomirov, S. A.,Kalosha, I. I.,Bobrov, S. A.,Masalov, N. V.,Nevar, N. M.,Tyvorskii, N. M.,Kel'in, A. V.,Kulinkovich, O. G.,Dzilinski, K.
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p. 230 - 237
(2007/10/03)
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- Tributylmagnesium ate complex-mediated novel bromine-magnesium exchange reaction for selective monosubstitution of dibromoarenes
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Lithium tributylmagnesate complex (n-Bu3MgLi), readily prepared from n-BuLi and n-BuMgCl (2:1), is a novel metallation agent. It is quite efficient for the selective mono-bromine-magnesium exchange of 2,6-dibromopyridine (1) under non-cryogenic conditions (at -10°C) to give a stable magnesate intermediate. Subsequent treatment with DMF gave 6-bromo-2-formylpyridine (3) in excellent yield. This method is also applicable for selective monosubstitution of several other kinds of dibromoarenes.
- Iida, Takehiko,Wada, Toshihiro,Tomimoto, Koji,Mase, Toshiaki
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p. 4841 - 4844
(2007/10/03)
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- Synthesis, transition temperatures, and optical properties of various 2,6-disubstituted naphthalenes and related 1-benzothiophenes with butylsulfanyl and cyano or isothiocyanato terminal groups
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Fourteen compounds based on 2,6-disubstituted naphthalenes or related 1-benzothiophene moieties with butylsulfanyl and cyano or isothiocyanato terminal groups have been synthesised. The transition temperatures of the compounds and their refractive indices have been determined and the derived values for the optical anisotropies, polarisabilities and order parameters have been calculated. With one exception (which also shows a smectic A phase), all the compounds with naphthyl and phenyl groups are solely nematogenic; for these compounds the naphthyl unit gives an average increase in T(N-I) value and melting point of 72 and 20°C respectively compared to the values for the compounds with a phenyl in place of the naphthyl unit. The incorporation of a 2,5-thiophene unit in place of phenyl lowers T(N-I) and when it is part of a 1-benzothiophene unit the depression is even greater. The naphthalene compounds increase the values of optical anisotropy by approximately 0.04, compared to the phenyl systems, mainly because they increase the refractive index of the e-ray (n values); compound 12 has an exceptionally high optical anisotropy (Δn value) of 0.54.
- Seed,Toyne,Goodby,Hird
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p. 2069 - 2080
(2007/10/03)
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- NLO dye compositions and use thereof in producing NLO elements
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Nonlinear optical elements are disclosed which comprise a polyimide which is solution and/or melt processible, and a poled NLO dye. Also disclosed is a process for making such elements, and devices in which they can be used. Disclosed NLO dyes include STR1
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- Photochemical Synthesis of Phenyl-2-thienyl Derivatives
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The irradiation (in benzene solution) of 5-bromo- and 5-iodo-thiophene-2-carbaldehyde or the corresponding methyl ketones furnishes the corresponding 5-phenyl derivatives.The same reactivity for other halogenothiophenes is reported: 3,5-dibromothiophene-2-carbaldehyde furnishes the 3-bromo-5-phenyl-2-thienyl derivative while the corresponding di-iodo compound yields 3,5-diphenylthiophene-2-carbaldehyde.In contrast, 5-acetyl-2,3-di-iodothiophene furnishes only the photosubstitution pruduct at C-5.Generally the iodine-containing compounds are more reactive and more stable under the reaction conditions than ones bearing bromine, in agreement with previous reports on the corresponding furan photochemistry.
- Antonioletti, Roberto,Auria, Maurizio D',Onofrio, Franco D',Piancatelli, Giovanni,Scettri, Arrigo
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p. 1755 - 1758
(2007/10/02)
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- KINETICS OF THE FORMYLATION OF THIOPHENE DERIVATIVES WITH N,N-DIMETHYLFORMAMIDE
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The kinetics of the formylation of five thiophene derivatives in the presence of phosphorus oxychloride and the formylation of thiophene in the presence of thionyl chloride were investigated.The effect of the condensing agent on the reaction rate is shown, and rate constants and the activation parameters are calculated.The isokinetic dependence and the Hammett dependence of the reactivities on the structure were established for this reaction series.The effect of the solvent on the formylation was studied.
- Freidlin, G.N.,Kuraeva, N.A.,Solop, K.A.
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p. 230 - 233
(2007/10/02)
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