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1.
本文合成了两系列2,5-取代的噻吩类衍生物1a-1f: 2,5-二(对烷氧基苯基乙炔基)噻吩和2a-2b: 2,5-二[(对烷氧基苯基乙炔基)-对-苯基乙炔基]噻吩)]并通过1H NMR, 13C NMR, HRMS和元素分析对其结构进行了表征。研究了结构与液晶性和光谱性之间的关系,结果表明:化合物1a-1f均为互变型向列相液晶,其液晶相通过DSC、PXRD和偏光显微镜得到确证,而具有更长共扼结构的化合物2a-2b却没有液晶性。分子结构中增加苯基乙炔基团,吸收光谱和发射光谱均发生红移,发光量子效率也显著提高。 相似文献
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合成了A-A-A型双苯乙烯基苯类化合物FR[2,5-二氰基-1,4-二(4'-氟苯乙烯基)苯],并采用核磁共振、红外光谱和元素分析等手段对其进行了表征.用飞秒脉冲诱导荧光光谱法分别研究了2个A-A-A型双苯乙烯基苯类化合物FR与CY[2,5-二氰基-1,4-二(4'-氰基苯乙烯基)苯]以及2个D-A-D型双苯乙烯基苯类化合物MO[2,5-二氰基-1,4-二(4'-甲氧基苯乙烯基)苯]和MA[2,5-二氰基-1,4-二(4'-二甲胺基苯乙烯基)苯]的单、双光子吸收与发射特性.实验结果表明,最大单光子吸收与发射波长随末端取代基供电子能力的增强而增大,末端强吸电子基化合物FR和CY具有相当高的荧光量子产率(分别为0.92与0.89)、较长的荧光寿命(分别为5.8与6.1 ns)及较大的双光子吸收系数(分别为19.1与20.5).末端带强吸电子基的化合物FR与CY的双光子吸收截面(δ,分别为6350 GM和6870 GM)比末端带供电子基的化合物MO和MA的δ(分别为270 GM与1790 GM)要大得多,表明A-A-A型双苯乙烯基苯类化合物具有异常大的δ. 相似文献
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测定了1,4-双(取代苯乙炔基)苯(Ⅰ)和反,反-1,4-双(β-取代苯乙烯基)苯(Ⅱ)的紫外光谱、荧光光谱.用CNDO/S-CI和HMO方法对苯乙炔、二苯乙炔和(Ⅰ)及苯乙烯、1,2-二苯乙烯和(Ⅱ)的激发能进行了计算和研究.讨论了化合物结构对光谱的影响. 相似文献
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测定了1,4-双(取代苯乙炔基)苯(Ⅰ)和反,反-1,4-双(β-取代苯乙烯基)苯(Ⅱ)的紫外光谱、荧光光谱。用CNDO/S-CI和HMO方法对苯乙炔、二苯乙炔和(Ⅰ)及苯乙烯、1,2-二苯乙烯和(Ⅱ)的激发能进行了计算和研究。讨论了化合物结构对光谱的影响。 相似文献
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以取代苯酚4和对氟苯乙酮(5)为原料,经4步反应合成关键中间体1-(4-取代苯氧苯基)乙胺(9),再与3种中间体2-氰基-3-乙氧基-2-戊烯酸乙氧乙酯(1)、2-氰基-3,3-二甲硫基丙烯酸乙氧乙酯(2)和2-氰基-3-氯-4,4,4-三氟丁烯酸乙氧乙酯(3)分别发生缩合反应,合成了3个系列共35个新2-氰基-3-[1-(4-取代苯氧基苯基)乙胺基]烯酸乙氧乙酯类化合物(10,11和12).所有新化合物的结构均经过1H NMR,13C NMR,19F NMR和HRMS的确证,并测试了目标化合物的除草活性,部分化合物在剂量为93.75 g/ha时,对双子叶植物油菜和苋菜的抑制率为100%. 相似文献
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1,3-偶极环加成反应合成1-(取代苄基)-1,2,3-三唑类化合物 总被引:10,自引:0,他引:10
利用苄氯和取代苄氯与叠氮化钠的亲核取代反应合成了一系列苯环上带有不同取代基团的苄基叠氮化合物,亲核取代反应速率受苯环上取代基的影响:吸电子基团的存在,可以促使反应更容易进行.合成的叠氮化合物与苯乙炔经1,3-偶极环加成反应得到了相应的取代苄基1,2,3-三唑类化合物,反应条件温和.这些1,2,3-三唑类目标化合物具有对热稳定的优点.用红外、核磁、元素分析、质谱等对合成的叠氮化合物和1,2,3-三唑类化合物的结构进行了表征,重点研究了1,3-环加成反应的规律.加成反应速率取决于叠氮化合物(偶极物)的极性,即与取代基的电负性有关:苯乙炔(亲偶极物)易于与缺电子的叠氮反应,反之亦然.同时在反应过程中观察到空间位阻效应:反应可以生成两种同分异构体,其中4-苯基-1,2,3-三唑是主要产物. 相似文献
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1,2-双(二溴甲基)苯及4位取代衍生物与反丁烯二腈在N,N-二甲基甲酰胺中反应12 h没有新的产物生成,在同样的条件下,加入碘化钾可使反应发生,主产物是2,3-二氰基萘及其6位取代衍生物,它的产率随加入的碘化钾的量不同而不同.当碘化钾的加入量相当于1,2-双(二溴甲基)苯及4位取代衍生物分子中溴的摩尔数,则1,2-双(二溴甲基)苯及其4位取代衍生物与反丁烯二腈基本作用完毕,反应产物主要是2,3-二氰基萘及其6位取代衍生物,产率87.1%.这个实验事实表明,碘化钾的作用机制不是传统意义上的催化剂而是一个反应试剂.据此,提出了上述反应的机理. 相似文献
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Koushik Saha Benson Joseph Rongala Ramalakshmi Dr. R. S. Anju Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7871-7878
Thermolysis of [Cp*Ru(PPh2(CH2)PPh2)BH2(L2)] 1 (Cp*=η5‐C5Me5; L=C7H4NS2), with terminal alkynes led to the formation of η4‐σ,π‐borataallyl complexes [Cp*Ru(μ‐H)B{R‐C=CH2}(L)2] ( 2 a – c ) and η2‐vinylborane complexes [Cp*Ru(R‐C=CH2)BH(L)2] ( 3 a – c ) ( 2 a , 3 a : R=Ph; 2 b , 3 b : R=COOCH3; 2 c , 3 c : R=p‐CH3‐C6H4; L=C7H4NS2) through hydroboration reaction. Ruthenium and the HBCC unit of the vinylborane moiety in 2 a – c are linked by a unique η4‐interaction. Conversions of 1 into 3 a – c proceed through the formation of intermediates 2 a – c . Furthermore, in an attempt to expand the library of these novel complexes, chemistry of σ‐borane complex [Cp*RuCO(μ‐H)BH2L] 4 (L=C7H4NS2) was investigated with both internal and terminal alkynes. Interestingly, under photolytic conditions, 4 reacts with methyl propiolate to generate the η4‐σ,π‐borataallyl complexes [Cp*Ru(μ‐H)BH{R‐C=CH2}(L)] 5 and [Cp*Ru(μ‐H)BH{HC=CH‐R}(L)] 6 (R=COOCH3; L=C7H4NS2) by Markovnikov and anti‐Markovnikov hydroboration. In an extension, photolysis of 4 in the presence of dimethyl acetylenedicarboxylate yielded η4‐σ,π‐borataallyl complex [Cp*Ru(μ‐H)BH{R‐C=CH‐R}(L)] 7 (R=COOCH3; L=C7H4NS2). An agostic interaction was also found to be present in 2 a – c and 5 – 7 , which is rare among the borataallyl complexes. All the new compounds have been characterized in solution by IR, 1H, 11B, 13C NMR spectroscopy, mass spectrometry and the structural types were unequivocally established by crystallographic analysis of 2 b , 3 a – c and 5 – 7 . DFT calculations were performed to evaluate possible bonding and electronic structures of the new compounds. 相似文献
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Facile Preparation of α‐Cyano‐α,ω‐Diaryloligovinylenes: A New Class of Color‐Tunable Solid Emitters 下载免费PDF全文
Dr. Peng An Nian‐Sheng Xu Prof. Hao‐Li Zhang Prof. Xiao‐Ping Cao Dr. Zi‐Fa Shi Wei Wen 《化学:亚洲杂志》2015,10(9):1959-1966
An efficient Knoevenagel condensation reaction was used to construct a series of α‐cyano‐α,ω‐diaryloligovinylenes, which show prominent fluorescence emission in the solid state. On investigating the effect of conjugation length on fluorescent properties, we found that the diene structure showed superior solid‐state luminescence. Furthermore, the emission color could be adjusted by introducing donor or acceptor functional groups at the terminal aryl groups. Full‐color emission in the visible region can be achieved by adding different functional groups to the α‐cyano‐α,ω‐diaryldivinylene moiety. The structure–property relationships were elucidated and some observations such as the substitution position effects were discussed. These compounds have potential applications as full‐color solid emissive candidates in material science and their simple structures allow them to be easily modified resulting in further interesting properties. 相似文献
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Saija Werner Doris Pospiech Dieter Jehnichen Kathrin Eckstein Hartmut Komber Peter Friedel Andreas Janke Franziskus Näther Uta Reuter Brigitte Voit Rosa Taurino Massimo Messori 《Journal of polymer science. Part A, Polymer chemistry》2011,49(4):926-937
A series of diblock copolymers of n‐pentyl methacrylate and methyl methacrylate (PPMA/PMMA BCP) with one or two terminal functional groups was prepared by sequential anionic polymerization of PMA and MMA using an allyl‐functionalized initiator and/or and end‐capping with allyl bromide. Allyl functional groups were successfully converted into OH groups by hydroboration. The morphology in bulk was examined by temperature‐dependent small‐angle X‐ray measurements (T‐SAXS) and transmission electron microscopy (TEM) showing that functional groups induced a weak change in d‐spacings L0 as well as in the thermal expansion behavior. T‐SAXS proved that the lamellar morphologies were stable over multiple heating/cooling cycles without order‐disorder transition (ODT) until 300 °C. While non‐functionalized BCP formed parallel lamellae morphologies, additional OH‐termination at the PMMA block forced in very thin films (ratio between film thickness and lamellar d‐spacing below 1) the generation of perpendicular lamellae morphology through the whole film thickness, as shown by Grazing‐incidence small‐angle X‐ray scattering experiments (GISAXS) measurements. Functionalized BCP were successfully used in thin films as templates for silica nanoparticles in an in‐situ sol–gel process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
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The present paper describes the preparation by conventional methods (when not available commercially) and the pKa-determination of the α-, β- and γ-isomers of pyridylethanamide, 3-pyridylpropanamide. 4-pyridylbutanamide, 5-pyridyl-pentanamide, pyridylmethanol, 2-pyridylethanol, 3-pyridylpropanol, 4-pyridyl-butanol, 5-pyridylpentanol, pyridylmethylamine, 2-pyridylethylamine, 3-pyridyl-propylamine, 4-pyridylbutylamine, and 5-pyridylpentylamine. While a field effect accounts for many variations in pKa as a function of chain length, marked inductive effects are operative in some methyl and ethyl homologs. The pKa-decreasing influence of an intramolecular H-bond is also apparent in some lower homologs belonging to the α-series. 相似文献
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Peter J. Roth Daniel Kessler Rudolf Zentel Patrick Theato 《Journal of polymer science. Part A, Polymer chemistry》2009,47(12):3118-3130
Five different polymers, poly[methyl methacrylate] (PMMA), poly[lauryl methacrylate] (PLMA), poly[diethylene glycol methacrylate] (PDEGMA), poly[N‐isopropylacrylamide] (PNIPA), and poly[styrene] (PS) prepared by the RAFT process and thus terminated with dithioesters were aminolyzed in the presence of S‐3‐butynyl methane thiosulfonate (MTS), which was synthesized in two steps. Analysis of the polymers by 2D NMR, UV–vis absorbance, and gel permeation chromatography revealed them to quantitatively carry acetylene end groups connected with disulfide bridges, indicating that functional MTS reagents can be employed for end group functionalization of RAFT polymers. This versatile method is of advantage compared with conjugations with functional maleimides, where isolation of terminal thiols is often required but inexpedient for poly[(meth)acrylates] because their terminal thiols may undergo backbiting and thus avoid conjugation. The acetylene‐terminated polymers were bound to an azide functionalized glass surface in a Cu(I) catalyzed cycloaddition. The modified surfaces exhibited water contact angles corresponding to the polarity of the attached polymers. In the case of the stimulus responsive polymers PNIPA and PDEGMA, the surfaces showed temperature‐dependent contact angles. The disulfide bond connecting the polymers to the surface could be selectively cleaved and resulted in all surfaces having the same contact angle, independent of the nature of the polymer prior attached to the surface. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3118–3130, 2009 相似文献
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Visible light‐induced thiol‐ene reaction: A new strategy to prepare Α,ω‐dithiol and Α,ω‐divinyl telechelic polythiolether oligomers 下载免费PDF全文
Wenchao Ma Dong Chen Lianying Liu Yuhong Ma Li Wang Changwen Zhao Wantai Yang 《Journal of polymer science. Part A, Polymer chemistry》2016,54(6):740-749
A new strategy is developed to prepare both α,ω‐dithiol and α,ω‐divinyl linear telechelic polythiolether oligomers by visible light induced thiol‐ene chemistry in the presence of a fac‐Ir(ppy)3 photoredox catalyst. Polythiolether oligomers of well‐defined end groups and controlled molecular weights have been successfully synthesized at varying monomer molar ratios of 1,4‐benzenedimethanethiol (BDMT) to diethylene glycol divinyl ether (DEGVE). 1H NMR and MALDI‐TOF MS analyses demonstrate that as‐prepared polythiolethers possess high end‐group fidelity, which is further supported by the successful polyaddition of polythiolethers bearing α,ω‐dithiol and α,ω‐divinyl groups. For example, with the α,ω‐dithiol‐ (Mn = 1900 g mol?1, PDI = 1.25) and α,ω‐divinyl‐terminated (Mn = 2000 g mol?1, PDI = 1.29) polythiolethers as macromonomers, the molecular weight of resulting polythiolether is up to 7700 g mol?1 with PDI as 1.67. The reactivity of the terminal thiol group is further confirmed by the addition reaction with N‐(1‐pyrenyl)maleimide. UV‐vis spectra and fluorescene measurements suggest that fac‐Ir(ppy)3 undergo a redox quenching process reacted with BDMT to generate thiyl free radicals. With these results, the mechanism of the thiol‐ene reaction catalyzed by photoredox catalyst is proposed. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 740–749 相似文献
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Dominik Albrecht Dr. Florian Vogt Thorsten Bach Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4284-4296
3‐(ω′‐Alkenyl)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 2 – 4 were prepared as photocycloaddition precursors either by cross‐coupling from 3‐iodo‐5,6‐dihydro‐1H‐pyridin‐2‐one ( 8 ) or—more favorably—from the corresponding α‐(ω′‐alkenyl)‐substituted δ‐valerolactams 9 – 11 by a selenylation/elimination sequence (56–62 % overall yield). 3‐(ω′‐Alkenyloxy)‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones 5 and 6 were accessible in 43 and 37 % overall yield from 3‐diazopiperidin‐2‐one ( 15 ) by an α,α‐chloroselenylation reaction at the 3‐position followed by nucleophilic displacement of a chloride ion with an ω‐alkenolate and oxidative elimination of selenoxide. Upon irradiation at λ=254 nm, the precursor compounds underwent a clean intramolecular [2+2] photocycloaddition reaction. Substrates 2 and 5 , tethered by a two‐atom chain, exclusively delivered the respective crossed products 19 and 20 , and substrates 3 , 5 , and 6 , tethered by longer chains, gave the straight products 21 – 23 . The completely regio‐ and diastereoselective photocycloaddition reactions proceeded in 63–83 % yield. Irradiation in the presence of the chiral templates (?)‐ 1 and (+)‐ 31 at ?75 °C in toluene rendered the reactions enantioselective with selectivities varying between 40 and 85 % ee. Truncated template rac‐ 31 was prepared as a noranalogue of the well‐established template 1 in eight steps and 56 % yield from the Kemp triacid ( 24 ). Subsequent resolution delivered the enantiomerically pure templates (?)‐ 31 and (+)‐ 31 . The outcome of the reactions is compared to the results achieved with 4‐substituted 5,6‐dihydro‐1H‐pyridin‐2‐ones and quinolones. 相似文献
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Massimo Gazzano Viscardo Malta Maria Letizia Focarete Mariastella Scandola Richard A. Gross 《Journal of Polymer Science.Polymer Physics》2003,41(10):1009-1013
The crystal structure of poly(ω‐pentadecalactone) (PPDL) synthesized by enzyme‐catalyzed polymerization was determined by full‐profile refinement. A pseudo‐orthorombic monoclinic unit cell with dimensions a = 7.49(1), b = 5.034(9), and c = 20.00(4)Å (fiber axis), and α = 90.06(4)° hosts two monomeric units belonging to polymer chains with opposite orientation, according to the P21 space‐group symmetry. A close similarity to the crystal structure of poly(?‐caprolactone) was evident. However, the even number of backbone atoms in the monomer unit of PPDL leads to a lower crystal symmetry. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1009–1013, 2003 相似文献
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Enantioselective Allylic Hydroxylation of ω‐Alkenoic Acids and Esters by P450 BM3 Monooxygenase 下载免费PDF全文
B.Sc. Katharina Neufeld Birgit Henßen Prof. Dr. Jörg Pietruszka 《Angewandte Chemie (International ed. in English)》2014,53(48):13253-13257
Chiral allylic alcohols of ω‐alkenoic acids and derivatives thereof are highly important building blocks for the synthesis of biologically active compounds. The direct enantioselective C? H oxidation of linear terminal olefins offers the shortest route toward these compounds, but known synthetic methods are limited and suffer from low selectivities. Described herein is an enzymatic approach using the P450 BM3 monooxygenase mutant A74G/L188Q, which catalyzes allylic hydroxylation with high to excellent chemo‐ and enantioselectivities providing the desirable secondary alcohols. 相似文献