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1.
A general and practical procedure for the syntheses of 3,4-di-hydropyrimidine-2(1H)-thiones by a one-pot condensation of aldehyde,β-ketoester or β-diketone and thiourea using La(OTf)3 as the catalyst is described.Mild reaction conditions,excellent yields as well as the environmentally friendly character of La(OTf)3 make it an important alternative to the classic acid-catalyzed Biginelli‘s reaction. 相似文献
2.
An improved method is developed by using strongly acidic cation exchange resin(001×1,H^+ form) as a catalyst for the synthesis of diphenyl 1-(N-benzyloxycarbonyl-amino) alkanephosphonates and 1-(N-benzyloxycarbonylamino) alkanephenyl phosphinic acids in high yields. 相似文献
3.
ZhengLI XiCunWANG 《中国化学快报》2002,13(8):717-720
The 1-aryloxyacetyl-4-(4′-nitrophenyloxyacetyl)-thiosemicarbazides (3a-h) are synthesized via reaction of 4-nitrophenyloxyacetyl chloride with ammonium thiocyanate and aryloxyaceic hydrazides (2a-h) under phase transfer catalysis and microwave irradiation in excellent yield. 相似文献
4.
ShouRiSHENG LuLingWU XianHUANG 《中国化学快报》2003,14(5):456-458
Polystyrene-supported 4-(phenylseleno)morpholine was synthesized and could be used as an efficient α-selenenylating agent for saturated aldehydes.α-Haloaldehydes were prepared by reaction of polystyrene-supported α-selenoaldehydes with bromine or sulfuryl chloride in good yield and high purity. 相似文献
5.
A simplified procedure for enantioselective synthesis of (S)-( )-2-(6′-methoxyl-2-naphthyl)propionic acid ((S)-( )-naproxen), starting from (6-methoxy-α-naphthyl)-1-propanone,with D-mannitol as auxiliary catalyzed by SmCl3 in one-pot is described. The yield is 87.5%(ee value 99%). 相似文献
6.
XinZhi ZongXingSI 《中国化学快报》2002,13(2):129-132
A series of novel compounds 3-(2-furyl)-4-aryl-1,2,4-triazole-5-thiones have been synthesized.All the compounds were characterized by spectral data and elemental analysis. The preliminary biological test showed that some of them exhibited excellent plant-growth regulative activities. 相似文献
7.
Novel blue light-emitting poly(aryl ether)s comprising of bipolar oligofluorene pendants as chromophores have been designed and synthesized,in which pyrimidine and arylamine moieties are utilized as the electron acceptor and electron donor,respectively.Through varying π bridge length from monofluorene to bifluorene and end-cappers from hydrogen to carbazole and diphenylamine,the emission color of the resulting polymers covers from deep blue to greenish blue,and their HOMO and LUMO levels can be modulated to facilitate charge injection to improve the device performance.Polymer lightemitting diodes(PLEDs) are fabricated with the device structure of ITO/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid)(PEDOT:PSS)(50 nm)/polymer(80 nm)/Ca(10 nm)/Al(200 nm).Among these polymers,P2Cz5F-Py with bifluorene bridge and carbazole end-capper shows excellent trade-off between the efficiency and emission wavelength,having a peak luminous efficiency as high as 1.26 cd/A and Commission Internationale de L’Eclairage(CIE) coordinates of(0.17,0.17). 相似文献
8.
α-甲基苯乙烯-异戊二烯)二嵌段共聚物的溶液性质 《功能高分子学报》2001,14(4):422-426
采用体积排斥色谱法(SEC)/示差折光指数(RI)/
-聚(α-甲基苯乙烯-异戊二烯)二嵌段共聚物的溶液性质直角激光光散射(RALLS)/示差粘度(DV)三检测联用技术,在THF为溶剂、25℃的条件下表征了聚(α-甲基苯乙烯-异戊二烯)(PαMS-PI)二嵌段共聚物;计算得到了PαMS-PI分子的无扰尺寸A为0.0778nm.mol 相似文献
9.
Jian Gong LIANG Hai Yan XIE Xin Ping AI Zhi Ke HE* Dai Wen PANG College of Chemistry & Molecular Sciences Wuhan University Wuhan 《中国化学快报》2004,15(11):1319-1322
Semiconductor quantum dots (QDs) present considerable advantages over bulk single-crystal semiconductors1. As a result of quantum confinement, they have unique optical and electronic properties such as broad excitation spectra, narrow, symmetric and tunable emission spectra2. In addition, QDs exhibit high photobleaching threshold and excellent photostability. They are starting to attract considerable attention as novel fluorescence probes in recent years3-6. Recently, Chen and Rosenzwei… 相似文献
10.
XinBinMA ShengPingWANG HongLiGUO GenHuiXU 《中国化学快报》2003,14(5):461-464
Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1(2.5 wt% Ti)catalyst.TS-1 catalyst,as a beterogeneous catalyst,showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts.Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol.the high selectivity was closely related to the weak acid sites over TS-1. 相似文献
11.
Kyung Moon Jung Kyung Hwan Kim Jung‐Il Jin Min Ju Cho Dong Hoon Choi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(22):7517-7533
New deep‐red light‐emitting phosphorescent dendrimers with hole‐transporting carbazole dendrons were synthesized by reacting tris(2‐benzo[b]thiophen‐2‐yl‐pyridyl) iridium (III) complex with carbazolyl dendrons by DCC‐catalyzed esterification. The resulting first‐, second‐, and third‐generation dendrimers were found to be highly efficient as solution‐processable emitting materials and for use in host‐free electrophosphorescent light‐emitting diodes. We fabricated a host‐free dendrimer EL device with configuration ITO/PEDOT:PSS (40 nm)/dendrimer (55 nm)/BCP (10 nm)/Alq3 (40 nm)/LiF (1 nm)/Al (100 nm) and characterized the device performance. The multilayered devices showed luminance of 561 cd/m2 at 383.4 mA/cm2 (12 V) for 15 , 1302 cd/m2 at 321.3 mA/cm2 (14 V) for 16 , and 422 cd/m2 at 94.4 mA/cm2 (18 V) for 17 . The third‐generation dendrimer, 17 (ηext = 6.12% at 7.5 V), showed the highest external quantum efficiency (EQE) with an increase in the density of the light‐harvesting carbazole dendron. Three dendrimers exhibited considerably pure deep‐red emission with CIE 1931 (Commission International de L'Eclairage) chromaticity coordinates of x = 0.70, y = 0.30. The CIE coordinates remained very stable with the current density. The integration of rigid hole‐transporting dendrons and phosphorescent complexes provides a new route to design highly efficient solution‐processable materials for dendrimer light‐emitting diode (DLED) applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7517–7533, 2008 相似文献
12.
Tadaaki Horii Toshinobu Shinnai Kazuhiko Tsuchiya Takeshi Mori Masashi Kijima 《Journal of polymer science. Part A, Polymer chemistry》2012,50(21):4557-4562
Carbazole and fluorene‐based random and alternating copolycondensates were synthesized to develop high‐performance blue light‐emitting polymers by improving electron injection ability of poly(N‐aryl‐2,7‐carbazole)s that showed intense blue electroluminescence (EL) with good hole‐injection and ‐transport ability. These copolycondensates absorbed light energy at about λmax = 390 nm in CHCl3 and 400 nm in film state, and fluoresced at about λmax = 417 nm in CHCl3 and 430 nm in the thin film state. Energy gaps between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of them were about 2.9 eV, and the energy levels of LUMO situated lower than that of corresponding polycarbazole. Polymer light‐emitting diode devices having configuration of indium tin oxide/poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate)/polymer/CsF/Al using the copolycondensates, poly(N‐arylcarbazole‐2,7‐diyl), and poly(9,9‐dialkylfluorene‐2,7‐diyl), emitted bluish EL at operating voltages lower than 7 V. The device embedded the random copolycondensate showed notably higher performance with maximum luminance of 31,200 cd m?2 at 11.0 V, and the current efficiencies observed under operating voltages lower than 7 V were higher than those of the other devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
13.
Seung Hee Yoon Jicheol Shin Hyun Ah Um Tae Wan Lee Min Ju Cho Yong Jae Kim Young Hoon Son Joong Hwan Yang Geesung Chae Jang Hyuk Kwon Dong Hoon Choi 《Journal of polymer science. Part A, Polymer chemistry》2014,52(5):707-718
Novel photo‐crosslinkable hole‐transport and host materials incorporated into multilayer blue phosphorescent polymer light‐emitting diodes (Ph‐PLEDs) were demonstrated in this study. The oxetane‐containing copolymers, which function as hole‐transport layers (HTL), could be cured by UV irradiation in the presence of a cationic photoinitiator. The composition of the two monomers was varied to yield three different hole‐transporting copolymers, [Poly(9,9′‐(5‐(((4‐(7‐(4‐(((3‐methyloxetan‐3‐yl)methoxy)methyl)phenyl)octan‐3‐yl)benzyl)oxy)methyl)?1,3‐phenylene)bis(9H‐carbazole)) ( P(mCP‐Ox)‐I , ‐II , and ‐III )]. In addition, monomer 1 was copolymerized with styrene to produce copolymer P(mCP‐Ph) as a host material for bis[2‐(4,6‐difluorophenyl)pyridinato‐C2,N](picolinato)iridium(III) (FIrpic), a blue‐emitting dopant. All mCP‐based copolymers displayed high glass transition temperatures (Tg) of up to 130–140 °C and triplet energies of up to 3.00 eV. The blue Ph‐PLEDs exhibited a maximum external quantum efficiency of 2.55%, in addition to a luminous efficiency of 8.75 cd A?1 when using the device configuration of indium tin oxide/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate)/ P(mCP‐OX)‐III / P(mCP‐Ph) :FIrpic(15 wt %)/3,3′‐[5′‐[3‐(3‐pyridinyl)phenyl][1,1′:3′,1′′‐terphenyl]‐3,3′′‐diyl]bispyridine/LiF/Al. The device bearing P(mCP‐Ox)‐III HTL, containing the highest composition of mCP unit, exhibited better performance than the other devices, which is attributed to induction of more balanced charge carriers and carrier recombination in the emissive layer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 707–718 相似文献
14.
Youjun He Yi Zhou Guangjin Zhao Jie Min Xia Guo Bo Zhang Maojie Zhang Jing Zhang Yongfang Li Fengling Zhang Olle Inganäs 《Journal of polymer science. Part A, Polymer chemistry》2010,48(8):1822-1829
A new benzodithiophene (BDT)‐based polymer, poly(4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene vinylene) (PBDTV), was synthesized by Pd‐catalyzed Stille‐coupling method. The polymer is soluble in common organic solvents and possesses high thermal stability. PBDTV film shows a broad absorption band covering from 350 nm to 618 nm, strong photoluminescence peaked at 545 nm and high hole mobility of 4.84 × 10?3 cm2/Vs. Photovoltaic properties of PBDTV were studied by fabricating the polymer solar cells based on PBDTV as donor and PC70BM as acceptor. With the weight ratio of PBDTV: PC70BM of 1:4 and the active layer thickness of 65 nm, the power conversion efficiency of the device reached 2.63% with Voc = 0.71 V, Isc = 6.46 mA/cm2, and FF = 0.57 under the illumination of AM1.5, 100 mW/cm2. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1822–1829, 2010 相似文献
15.
Ab initio investigation of 2,2′‐bis(4‐trifluoromethylphenyl)‐5,5′‐bithiazole for the design of efficient organic field‐effect transistors
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Shamoon Ahmad Siddiqui Ali Al‐Hajry M. S. Al‐Assiri 《International journal of quantum chemistry》2016,116(5):339-345
The initial molecular structure of 2,2′‐bis(4‐trifluoromethylphenyl)‐ 5,5′‐bithiazole has been optimized in the ground state using density functional theory (DFT). The distribution patterns of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) have also been evaluated. To shed light on the charge transfer properties, we have calculated the reorganization energy of electron λe, the reorganization energy of hole λh, adiabatic electron affinity (EAa), vertical electron affinity (EAv), adiabatic ionization potential (IPa), and vertical ionization potential (IPv) using DFT. Based on the evaluation of hole reorganization energy, λh, and electron reorganization energy, λe, it has been predicted that 2,2′‐bis(4‐trifluoromethylphenyl)‐5,5′‐bithiazole would be a better electron transport material. Finally, the effect of electric field on the HOMO, LUMO, and HOMO–LUMO gap were observed to check its suitability for the use as a conducting channel in organic field‐effect transistors. © 2015 Wiley Periodicals, Inc. 相似文献
16.
Chia‐Shing Wu Ya‐Ju Yang Szu‐Wen Fang Yun Chen 《Journal of polymer science. Part A, Polymer chemistry》2012,50(18):3875-3884
This study reports the synthesis, curing, and optoelectronic properties of a solution‐processable, thermally cross‐linkable electron‐ and hole‐blocking material containing fluorene‐core and three periphery N‐phenyl‐N‐(4‐vinylphenyl)benzeneamine ( FTV ). The FTV exhibited good thermal stability with Td above 478 °C in nitrogen atmosphere. The FTV is readily cross‐linked via terminal vinyl groups by heating at 160 °C for 30 min to obtain homogeneous film with excellent solvent resistance. Multilayer PLED device [ITO/PEDOT:PSS/cured‐ FTV /MEH‐PPV/Ca (50 nm)/Al (100 nm)] was successfully fabricated using solution processed. Inserting cured‐ FTV is between PEDOT:PSS and MEH‐PPV results in simultaneous reduction in hole injection from PEDOT:PSS to MEH‐PPV and blocking in electron transport from MEH‐PPV to anode. The maximum luminance and maximum current efficiency were enhanced from 1810 and 0.27 to 4640 cd/m2 and 1.08 cd/A, respectively, after inserting cured‐ FTV layer. Current results demonstrate that the thermally cross‐linkable FTV enhances not only device efficiency but also film homogeneity after thermal curing. FTV is a promising electron‐ and hole‐blocking material applicable for the fabrication of multilayer PLEDs based on PPV derivatives. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 000: 000–000, 2012 相似文献
17.
Poly‐p‐phenylenebenzobisoxazole (PBO) contains a fully conjugated rod‐like backbone entailing excellent optoelectronic properties and superior stabilities. Poly(2,3‐dihydrothieno‐1,4‐dioxin):polystyrenesulfonate (PEDOT:PSS) is a hole transferring medium, which was spun into a thin‐film between PBO and indium‐tin‐oxide to facilitate photovoltaic (PV) effect by forming a donor‐acceptor interlayer to separate and to transport photoinduced charges. Optimum PBO thickness for PV heterojunctions was about 71 nm at which the hole transferring PEDOT:PSS generated the maximum short circuit current (Isc) at a thickness of 115 nm. By using a layer of lithium fluoride (LiF) as an electron transferring layer adhering to Al cathode, the most open circuit voltage (Voc) and Isc were achieved with a LiF thickness of 1–2 nm because of possible electric dipole effect leading to an increase of Voc from 0.7 to 0.92 V and of Isc from about 0.1 to 0.2 μA. No PV response was observed for all PBO homojunctions because of insufficient exciton separation into electrons and holes. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 988–993, 2007 相似文献
18.
Highly Emissive Luminogens Based on Imidazo[1,2‐a]pyridine for Electroluminescent Applications
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Natarajan Nagarajan Gunasekaran Velmurugan Asit Prakash Dr. Nanda Shakti Prof. Dr. Monica Katiyar Prof. Dr. Ponnambalam Venuvanalingam Prof. Dr. Rajalingam Renganathan 《化学:亚洲杂志》2014,9(1):294-304
A search for novel organic luminogens led us to design and synthesize some N‐fused imidazole derivatives based on imidazo[1,2‐a]pyridine as the core and arylamine and imidazole as the peripheral groups. The fluorophores were synthesized through a multicomponent cascade reaction (A3 coupling) of a heterocyclic azine with an aldehyde and alkyne, followed by Suzuki coupling and a multicomponent cyclization reaction. All of the compounds exhibited interesting photophysical responses, especially arylamine‐containing derivatives, which displayed strong positive solvatochromism in the emission spectra that indicated a more polar excited state owing to an efficient charge migration from the donor arylamine to the imidazo[1,2‐a]pyridine acceptor. The quantum yields ranged from 0.2 to 0.7 and depended on the substitution pattern, most notably that based on the donor group at the C2 position. Moreover, the influence of general and specific solvent effects on the photophysical properties of the fluorophores was discussed with four‐parameter Catalán and Kamlet–Taft solvent scales. The excellent thermal, electrochemical, and morphological stability of the compounds was explored by cyclic voltammetry, thermogravimetric analysis, and AFM methods. Furthermore, to understand the structure, bonding, and band gap of the molecules, DFT calculations were performed. The performance of the electroluminescence behavior of the imidazo[1,2‐a]pyridine derivative was investigated by fabricating a multilayer organic light‐emitting diode with a configuration of ITO/NPB (60 nm)/EML (40 nm)/BCP (15 nm)/Alq3 (20 nm)/LiF (0.5 nm)/Al(100 nm) (ITO=indium tin oxide, EML=emissive layer, BCP=2,9‐dimethyl‐4,7‐diphenyl‐1,10‐phenanthroline, Alq3=tris(8‐hydroxyquinolinato)aluminum), which exhibited white emission with a turn‐on voltage of 8 V and a brightness of 22 cd m?2. 相似文献
19.
Masahiro Funahashi Prof. Dr. Fapei Zhang Dr. Nobuyuki Tamaoki Dr. Jun‐ichi Hanna Prof. Dr. 《Chemphyschem》2008,9(10):1465-1473
5‐Hexyl‐5′′‐hexynyl‐2,2′:5′,2′′‐terthiophene exhibits the smectic E phase below 200 °C and does not crystallize when it is cooled to ?100 °C. Between 200 and ?100 °C, non‐dispersive transport is observed for holes and electrons with time‐of‐flight spectroscopy. Over the entire temperature range, the electron mobility is approximately twice as high as that of the hole. The hole and electron transport characteristics in the smectic phase below 0 °C are explained by the Gaussian disorder model, which was proposed for amorphous organic semiconductors. The disorder parameters, σ and Σ, are almost the same for holes and electrons. However, the pre‐exponential parameter μ0 for the electron is twice as large as that for the hole, which can be attributed to the difference in the extension of the LUMO of the molecules. The energetic disorder σ is primarily determined by the disorder in the orientation of the permanent dipoles of liquid crystal molecules. 相似文献
20.
Zhengfeng Chang Prof. Shanghui Ye Bairong He Zirong Bei Liya Lin Prof. Ping Lu Bin Chen Dr. Zujin Zhao Prof. Huayu Qiu 《化学:亚洲杂志》2013,8(2):444-449
Excimers are generally considered as detrimental to OLEDs. For pyrene‐based chromophores, however, this is not always true. In this contribution, two new methylated tetraphenylpyrenes, 1,3,6,8‐tetra‐o‐tolylpyrene (TTPy) and 1,3,6,8‐tetrakis(3,5‐dimethylphenyl)pyrene (TDMPPy), were synthesized through Suzuki coupling reactions. TDMPPy absorbs and emits light at longer wavelengths than TTPy due to its more planar conformation and thus better conjugation. TDMPPy is prone to excimer formation, thus leading to a strong bathochromic shift (84 nm) in the photoluminescence spectrum of its film. TDMPPy exhibits efficient electroluminescence originating from pyrene excimers, affording a maximum luminance of 26 670 cd m?2 and a current efficiency as high as 10.8 cd A?1 in a non‐doped OLED (ITO/PEDOT:PSS (50 nm)/NPB (30 nm)/TDMPPy (30 nm)/TPBI (40 nm)/Ca:Ag). 相似文献