Synthesis and characterisation of thieno[3,2-b]thiophene-based linear shaped liquid crystals

A series of thieno[3,2-b]thiophene-based liquid crystalline molecules has been synthesised. To investigate the effects of alkyl substituent groups and structure of mesogenic cores, eight kinds of thieno[3,2-b]thiophene-based molecules containing different alkyl substituent groups and mesogenic cores have been synthesised. These molecules were characterised by differential scanning calorimetry, polarising optical microscopy, ultraviolet–visible absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and polarised fluorescence spectroscopy. The results indicated that the thieno[3,2-b]thiophene-based donor-acceptor-donor (D-A-D) type molecules showed the presence of a smectic A phase. Changes in the length of alkyl substituents and mesogenic cores affected the phase transitions, optical and electrochemical properties of the molecules.     

Effects of Replacement on the Optical Properties of Narrow Bandgap Polymers: Comparing the Difference Between Thieno[3,2-b]thiophene Units and Thiophene Units

The effects of replacement on the optical properties of diketopyrrolopyrrole(DPP)-based polymers were discussed through replacing the thieno[3,2-b]thiophene units by thiophene units.It is easy to see that the role of replacement would lead to blue shift of steady-state absorption spectrum when thieno[3,2-b]thiophene units is replaced by thiophene units.Meanwhile,the transient absorption data indicate that the role of replacement would not change the relaxation mechanism of polymer,but is able to adjust the photo-excitation relaxation rate of polymer.Their intensity-dependent dynamic curves show that the exciton-exciton annihilation(EEA)would participate in the relaxation process when the polymer is in the aggregation.Through comparing the EEA data between the polymers,it is found that the role of replacement would change the spatial distribution of exciton.     

2,5-二(2-菲基)-[3,2-b]并二噻吩的合成、表征及在有机薄膜晶体管中的应用

本文合成了2,5-二(2-菲基)-[3,2-b]并二噻吩(PhTT), 表征了其基本的物理和化学性质, 制备了相应的有机薄膜晶体管.     

齐聚[3,2-b]并二噻吩的合成、表征及其在有机薄膜晶体管中的应用

通过Stille偶联反应合成了5.5"-二辛基.2.2':5'2'-三联[3,2-b]并二噻吩,并对该化合物的物理化学性质以及真空蒸镀薄膜的结构和形貌进行了详细表征.以这一化合物作为半导体层、采用顶电极结构制备了有机薄膜晶体管,并对薄膜生长基底温度做了优化,发现基底温度为100℃时器件性能最好,迁移率达到0.13 cm2/V·s,开关比为7×103,阈值电压为-19V.     

Phenyl isothiocyanate in heterocyclic synthesis: Novel synthesis of thiazoles,thieno[2,3-b]pyridine,thiophene and thieno[3,2-c]pyridazine derivatives

Summary The enamino nitriles1 and2 react with phenyl isothiocyanate followed by cyclization with -haloketones3 and10 to afford in each case the thiazole5, thiophene11 and the thieno[2,3-b]pyridine derivatives19 and21. Chemical and spectroscopic evidences for the structures of the new compounds are described.

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Phenylisothiocyanate in der Heterocyclensynthese: Neue Synthesen für Thiazol-, Thieno [2,3-b]pyridin-, Thiophen- und Thieno[3,2-c]pyridazin-Derivate

Zusammenfassung Die Enamin-nitrile1 und2 ergaben nach Reaktion mit Phenylisothiocyanaten und nachfolgender Cyclisierung mit -Halogenketonen3 und10 die entsprechenden Thiazole5, die Thiophene11 und die Thieno[2,3-b]pyridine19 und21. Chemische und spektroskopische Untersuchungen wurden als Strukturbeweise für die neuen Verbindungen herangezogen.

     

受体强度及D/A比对D-A型共轭聚合物几何结构和电子性质的影响研究

以Thieno[3,2-b]thiophene(TT)为电子供体(D),Benzo[c][1,2,5]thiadiazole(BT)、[1,2,5]thiadiazolo[3,4-g]quinoxaline(Td Q)、和Benzobis[1,2,5]thiadiazole(BBT)为电子受体(A),设计了供体-受体摩尔比(D/A比)分别为1∶1和2∶1的6种供体-受体交替排列的D-A型共轭聚合物.采用杂化的密度泛函方法(B3LYP),在6-31G(d)理论水平下研究了其几何结构和电子性质.研究发现,电子受体接受电子的能力和D/A比对基于TT的D-A型共轭聚合物的几何结构和电子性质有重要影响.对于D/A比相同的聚合物,电子受体接受电子的能力增强,聚合链上桥键的键长缩短,供体环上的碳碳双键的平均键长(L_(AD))增大而碳碳单键平均键长(L_(AS))减小.对由相同电子供体和受体构成的聚合物,D/A比增加,桥键变长.电子受体对D/A比为2∶1的聚合物的性质影响有显明的规律.当电子受体接受电子的能力增强,聚合物的能隙(Eg)变窄、价带(W_(VB))和导带(W_(CB))变宽、载流子有效质量(m_H和m_L)减小.研究发现,p-TdQ-TT和p-BBT-DTT能隙窄,能带相对较宽、载流子有效质量小,可能是的潜在的本征导电聚合物材料.     

New star-shaped molecules derived from thieno[3,2-b]thiophene unit and triphenylamine

A series of new substituted triphenylamine (TPA) derivatives with alkyl thieno[3,2-b]thiophene and thiophene units were synthesized in a combinatorial manner. Suzuki coupling of a dioxaborolane TPA derivative and 2-bromo-3-nonylthieno[3,2-b]thiophene or Stille coupling of fresh stannyl thieno[3,2-b]thiophene was used. All compounds were characterized by ¹H and ¹³C NMR, HRMS, UV-vis spectrometry and DSC measurements. It was demonstrated that the optical and thermal properties of these materials can be tuned by varying both the conjugation length and thienothiophene and thiophene combination on the TPA branches. Moreover, the measured molar extinction coefficients were increasing from 63,000 (λ_max = 354 nm) to 131,000 L mol⁻¹ cm⁻¹ (λ_max = 428 nm) for TPA-thienothiophenes and TPA-bithiophene thienothiophenes, respectively. Some of them showed molecular glass behavior.     

Novel ferroelectric liquid crystals based on fused thieno[3,2-b]furan and thieno[3,2-b]thiophene cores

Several series of new benzofused thieno[3,2-b]furan- and thieno[3,2-b]thiophene-based derivatives have been synthesized and their mesomorphic properties investigated. All the studied compounds exhibit a SmC* phase with very wide temperature interval. Additionally, some types of the compounds show the cholesteric, SmA or blue phase. In the ferroelectric SmC* phase we evaluated physical properties of relevance for possible applications.     

A concise synthesis of functionalized 2,3-dihydrofuro[3,2-b], [3,2-c], and [2,3-b]pyridines

A strategy for the efficient and rapid one-pot synthesis of 2-aryl-2,3-dihydrofuro[3,2-b], [3,2-c], and [2,3-b]pyridines from readily available o-nitropicolines and aromatic aldehydes is described. The key transformation involves reaction of o-nitropicolines with aromatic aldehydes in the presence of TBAF and Hünig's base giving rise to functionalized products having molecular complexity suitable for further manipulation.     

Synthesis,Characterization, and Crystal Structure of One Novel Indolo[3,2-b]carbazole Derivative

Indolocarbazole derivatives have been reported to be promising organic semicon- ductor candidates and electroluminescent （EL） materials. One novel indolocarbazole derivative, 2,8-acetyl-5,11-dihexyl-6,12-（di-p-tolyl）-5,11-indolo[3,2-b]carbazole （YK4）, has been synthesized, and its crystal structure has also been carefully studied. YK4 is triclinic, space groups Pi with a = 9.409（5）, b = 13.974（5）, c = 15.488（5） A, α = 90.281（5）, β = 105.456（5）, Z= 93.728（5）°, M,. = 688.94, V= 1958.1（14） A3, Z = 2, Dc.= 1.168 g/cm-3,μ = 0.070 mm-1, F（000） = 740, Rint = 0.0475, R （I〉 20（/）） = 0.1146, wR （I〉 20（/）） = 0.2186, R（all data） = 0.2192 and wR （all data） = 0.2701. Like other indolo[3, 2-b]carbazole derivatives which were introduced in the 5- and 11-positions, the intermolecular short contacts are localized between the pendant groups and acetyl groups of the neighboring indolocarbazole molecules. The molecule of YK4 possesses poor face-to-face π-π stacking between two adjacent molecules in the crystal. The calculated bond lengths and bond angles of YK4 also proved the result of crystallography.     

Photochromic dihetarylethenes. 6. Photochromic derivatives of thieno[3,2-b]thiophene

1,2-Bis{5-(2-benzothiazolyl)-2-methyl-6-trifluoromethylthieno[3,2-b]thiophen-3-yl}hexafluorocyclopentene possessing high fatigue resistance was synthesized for the first time. Its photochromic and fluorescence properties were studied. The structure of its cyclic form was established by X-ray diffraction analysis.     

Novel 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylate esters: Highly efficient synthesis and mesogenic evaluation of a new class of materials exhibiting the smectic C phase

A series of alkyl 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylates were prepared via a direct, efficient Pd(0)-catalysed Suzuki–Miyaura coupling approach. A series of long-chain alkyl thieno[3,2-b]thiophene-2-carboxylate esters, synthesised from newly reported alkyl mercaptoacetates, were elaborated into the target compounds via regioselective (C-5) halogenation followed by cross-coupling with 4-alkoxyphenyltrifluoroborate salts. As expected, these target alkyl 5-(4-alkoxyphenyl)thieno[3,2-b]thiophene-2-carboxylate ester mesogens exhibited the orthogonal smectic A phase; notably, they are the first materials built on the thieno[3,2-b]thiophene motif to also exhibit the smectic C mesophase.     

Synthesis, complexation, and fluorescence behavior of 3,4-dimethylthieno[2,3-b]thiophene carrying two monoaza-15-crown-5 ether groups

A novel fluoroionophore 1 based on 3,4-dimethylthieno[2,3-b]thiophene bearing two monoaza-15-crown-5 ethers at 3- and 4-positions was prepared. UV–vis and fluorescence responses of compound 1 upon the addition of alkali and alkaline earth metal cations were evaluated in acetonitrile solution. Receptor 1 showed unique response for Ba²⁺ due to the formation of an intramolecular sandwich complex.     

Synthesis and Herbicidal Activity of 2-Benzoyliminopyrimido[3,2-b]-1 2,4-Thiadiazolines

SincethesynthesisandherbicidalactivityofDPX-4l89wasreportedinl98o,awidevarietyofsulfonylureaswithimprovedselectivityand/oreffectivenesshavebeendeveloped'-'.Inacontinuingstudyonthesynthesisandherbicidalactivityofthiophenesulfonylureaandsubstitutedbenzenesulfonylureaderivatives'-',wehavefoundthatsulfonylureaherbicideshaveexcellentherbicidalactivityagainstawiderangeofweeds,butmostofthemwerenotselectivelyactiveherbicides.Inthispaperwedescribethesynthesisandherbicidalactivityofthirteen3-benzoly-l-…     

New liquid crystals derived from thiophene connected to the 1,2,4-oxadiazole heterocycle

In this study, eight new compounds derived from thiophene were synthesised and characterised. The four symmetrical compounds contain two heterocyclic 1,2,4- oxadiazole on each side of the 2,5-disubstituted thiophene, and the four non-symmetrical compounds contain alkyne groups as a spacer replacing one of these heterocycles. Some of the compounds presented liquid crystalline properties with smectic and nematic mesophases. The non-symmetrical compounds presented low emission of blue light.     

Fluorescent liquid crystalline compounds with 1,3,4-oxadiazole and benzo[b]thiophene units

A series of fluorescent liquid crystalline compounds containing 1,3,4-oxadiazole and benzo[b]thiophene units have been prepared. In CH₂Cl₂ solution, these compounds displayed a fluorescent emission with λ_max at 422–426 nm and quantum yields of 41–48%. Most of them exhibited thermotropic liquid crystalline properties with nematic and/or smectic A phases with excellent thermal stability. This work revealed that longer terminal alkoxy chains would be detrimental to the formation of mesophases for such kind of compounds. The effect of the terminal groups on mesomorphic and spectroscopic property is discussed.     

Synthesis of New 2-[(Substituted-pyrazolin-1-yl)carbonyl]-thieno[2,3-b]pyridine Derivatives

The reaction of 3-amino-4,6-dimethyl-2-thieno[2,3-b]pyridine carbohydrazide ( 1 ) with appropriate chalcones 2a-2d in the presence of acid catalyst produced the corresponding 3-amino-2-[(3,5-disubstituted-pyrazolin-1-yl)carbonyl]-4,6-dimethylthieno[2,3-b]pyridines 3a-3d . 3-Amino-2-[(3-substituted-pyrazolin-1-yl)carbonyl]-4,6-dimethylthieno[2,3-b]pyridines 7a, 7b were also obtained by the cyclization reaction of carbohydrazide 1 with Mannich base derivatives 6a, 6b under basic condition.     

SYNTHESIS AND REACTIONS OF SOME NEW THIENO[2,3-b]-PYRIDINES AND THE ANTIMICROBIAL EFFECTS

Abstract

3,5-Dicyano-6-mercapto-4-phenylpyridin-2(1H)-one (1) was reacted with ethyl chloroacetate to give compound (II) which on reaction with hydrazine hydrate gave the corresponding hydrazide derivative (III). Acylation of (III) with acetic acid, phenylisocyanate, or phenylisothiocyanate gave different monoacyl derivatives (IV-VI). Condensation of III with aromatic aldehydes and acetylacetone gave compounds VII_a-c, VIII respectively. Compound I was reacted with chloroanilides, bromoacetone and phenacyl bromide to yield the IX-XI; these and compound II gave thieno[2,3-b]-pyridines (XU-XV) on treatment with sodium ethoxide solution. Reaction of XII with acetic anhydride gave the diacetyl derivative XVI. Hydrolysis of compound XII with sodium hydroxide gave the corresponding acid (XVII) which on treatment with acetic anhydride gave the oxazine derivative (XVIII). Reaction of oxazine compound XVIII with ammonium acetate and hydrazine hydrate gave pyrido[3′,2′:4,5] thieno[3,2-d]pyrimidin-4.7-dione derivative (XIX) and (XX) respectively. The N-amino derivative (XX) was reacted with 4-nitrobenzaldehyde to give the corresponding azomethine (XXI).

Significant in vitro gram-positive and gram negative antibacterial activities as well as anti-fungal effect were observed for some members of the series.     

噻吩并[2,3-b]吡啶类化合物的合成及生物活性

用邻氨基噻吩腈与不同结构的二羰基化合物反应,合成了新的多取代噻吩并吡啶类衍生物4-氨基-5-取代羰基噻吩并[2,3-b]吡啶-6-酮。用元素分析、红外光谱、核磁共振氢谱和质谱等测试技术对所合成化合物的结构进行了表征。初步生物活性测试表明,该类化合物有较好的杀菌活性和一定的除草活性。