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5‐(2‐Bromoacetyl)‐2,3,4‐trisubstituted‐thiophene was used as a synthetic intermediate to prepare a series of thiophene derivatives and thiophene incorporating oxazole, imidazole, thiazole, pyrrole, and pyridine rings via substitution and cyclo‐condensation reactions. The data were extracted from the spectra of the resulting products confirmed their suggested structures. The newly synthesized compounds were screened to evaluate their in vitro antimicrobial activity vs several positive and negative gram bacteria and fungi. The screening data revealed that the thiophene derivative 7a, incorporating a thiazole ring, displayed strong activity against all tested microorganisms when compared with the antibiotics used. [ABSTRACT FROM AUTHOR]

We reported here reactions of 2‐bromo‐1‐(4‐methyl‐2‐(tosylamino)thiazol‐5‐yl)ethanone 1 with 2‐cyanoethanethioamide afforded new 2‐cyanomethylthiazole derivative. The reaction of the latter with arylidenemalononitrile derivatives afforded thiazolo[3,2‐a]pyridine derivatives. Also, compound 1 was subjected to a one‐pot four component Gewald reaction with molecular sulfur, malononitrile and aromatic aldehydes in the presence of L‐proline afforded 2‐aminothiophene derivatives. The structure of the newly synthesized compounds was established based on its elemental and spectral data. [ABSTRACT FROM AUTHOR]

Despite a significant work that has been done on thiophene, continuous efforts are still being made by the researchers to identify novel heterocyclic compounds with potential bioactivities. Thiophene nucleus has been extensively utilized by the researchers across the globe for the development of diverse bioactive heterocycles for hitting a wide range of biological targets. This review throws light on synthetic approaches that have been used for the synthesis of potential thiophene derivatives followed by the depth analysis of them with respect to their pharmacological significance. This review can help the medicinal chemists and researchers to develop novel leads having thiophene nucleus with high efficacy and reduced side effects. [ABSTRACT FROM AUTHOR]

Due to a wide range of applications in electronic materials, polythiophenes attract considerable attention in organic and polymer syntheses as well as in materials science. For the purpose of developing the practical synthetic protocol, this review focuses on the deprotonative pathway in the preparation of thiophene organometallic monomer, which was shown to be effective employing 2‐halo‐3‐substituted thiophene as a monomer precursor. The thus metallated thiophene monomer was shown to undergo polymerization by nickel(II) complex catalysis, with which highly regioregular head‐to‐tail (HT)‐type polythiophenes were obtained with controlled molecular weight and molecular weight distribution. Several polythiophene derivatives with modified thiophene‐ring and side‐chain structures were shown to be designed in order to achieve the designed functionality as materials. [ABSTRACT FROM AUTHOR]

A series of trigonal-shaped molecules (TPyT and TPyP) and a polymer (P2TPy) with donor–acceptor–donor (D–A–D) structural arrangement were designed with thiophene and 2,4,6-trisubstituted pyridine as the backbone i.e., a 4-(4-(decyloxy)phenyl)-2,6-di(thiophen-2-yl)pyridine core structure, for the first time and synthesized via a microwave assisted one pot reaction. The extension of conjugation of the system by substituting thiophene acrylonitrile (TPyT) and phenyl acrylonitriles (TPyP and P2TPy) via low cost condensation reactions improved the linear optical, electronic and thermal properties of the synthesized compounds. Furthermore, the nonlinear absorption (NLA) was also enriched appreciably by increasing the conjugation. The three compounds showed an "effective two-photon absorption" phenomenon with the NLA coefficient (βeff) of the order of 10−10 m W−1. The suitability to be utilized in the fabrication of all-optical limiting devices is best achieved by polymer P2TPy as it exhibits substantially higher βeff (7.02 × 10−10 m W−1) and an extremely low optical limiting threshold (1.42 J cm−2). [ABSTRACT FROM AUTHOR]

Hybrid imidazolium SILCs (supported ionic liquid catalysts) were prepared on the basis of H3PMo12O40 and H3PW12O40, grafted to mesoporous silicas of two types: silica gel and silochrome. They are active and stable catalysts for the peroxide oxidation of thiophene and thioanisole and oxidative desulfurization of diesel fuel. The structure of heteropolyanions on the surface depends on the silica nature and the Im: HPA ratio; a decrease in this ratio leads to their partial destruction. The specific activity (TOF) for the conversion of thiophene, which is the most oxidation-resistant sulfur-containing heterocycle, was 80–100 h−1 for W derivatives and 40–47 h−1 for Mo derivatives, which exceeds the values known from the literature. The use of W catalysts reduces the sulfur content in diesel fuel from 1080 to 7–8 ppm. [ABSTRACT FROM AUTHOR]

Conditions for the Gewald synthesis of 2-amino-5,5-dimethyl-4,7-dihydro-5H-thieno[2,3-c]pyrans from 2,2-dimethyltetrahydropyran-4-ones have been optimized, and the yields have been improved. A procedure has been developed for the synthesis of new pyrano[4′,3′:4,5]thieno[2,3-b]pyridines by the Thorpe–Ziegler reaction of thieno[2,3-c]pyrans. Anticonvulsant activity of the synthesized compounds was studied. [ABSTRACT FROM AUTHOR]

The increasing level of antimicrobial resistance in pathogenic bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a major public health concern. Thus, in this context, a novel series of 1,3,4‐oxadiazole‐substituted thiophenes (4 a–m) and 1,2,4‐triazole (6 a–m) substituted thiophene derivatives were synthesized. Characterization of all the synthesized derivatives was done by various spectroscopic techniques such as 1H NMR, 13C NMR spectroscopy and mass spectrometry, and evaluated for antimicrobial activity against various pathological strains using broth dilution and disc diffusion method. In particular, compound 6 e and 4 e exhibited significant inhibitory potential with MIC ranging from 2–7 μg mL−1 against S. aureus, B. subtilis, P. aeruginosa and E. coli. Additionally, compound 6 e was found to be highly potent against methicillin resistant S. aureus (MRSA; MIC=2 μg mL−1). Molecular docking studies were also performed to confer the possible mode of action and association studies indicate the binding of potent active compound with DHFR enzyme (Ka=2.10×103 M−1). Further, the mechanism of action has also been explored by atomic force microscopy (AFM), which reveals the bacterial cell wall deformity and cell wall rupturing that may lead to bacteria cell death. Additionally, in silico ADME prediction study suggested the drug like properties of active compounds. [ABSTRACT FROM AUTHOR]

The question whether organic compounds occur on Mars remained unanswered for decades. However, the recent discovery of various classes of organic matter in martian sediments by the Curiosity rover seems to strongly suggest that indigenous organic compounds exist on Mars. One intriguing group of detected organic compounds were thiophenes, which typically occur on Earth in kerogen, coal, and crude oil as well as in stromatolites and microfossils. Here we provide a brief synopsis of conceivable pathways for the generation and degradation of thiophenes on Mars. We show that the origin of thiophene derivatives can either be biotic or abiotic, for example, through sulfur incorporation in organic matter during early diagenesis. The potential of thiophenes to represent martian biomarkers is discussed as well as a correlation between abundances of thiophenes and sulfate-bearing minerals. Finally, this study provides suggestions for future investigations on Mars and in Earth-based laboratories to answer the question whether the martian thiophenes are of biological origin. [ABSTRACT FROM AUTHOR]

The reaction of the 3-oxo-N,3-diphenylpropan-amide (3) with either malononitrile or ethyl cyanoacetate in ammonium acetate gave the 1,2-dihydropyridine derivatives 6a or 6b, respectively. On the other hand, carrying the same reaction in the presence of triethylamine gave the 1,6-dihydropyridine derivatives 7a and 7b, respectively. Moreover, compound 3 reacted with 2-aminoprop-1-ene-1,1,3-tricarbonitrile to give the pyridine derivative 9. Compound 7b reacted with the active methylene derivatives 10a,b and 4a,b to give the naphthyridine derivatives 11a,b and 12a,b; respectively. Compound 3 was also used for the synthesis of thiophene derivatives 13a,b and 16a,b. In addition, the reaction of ethyl benzoylacetate (1) with o-phenylene diamine gave the benzimidazole derivative 18. The reactivity of the latter product towards different reagents was studied to give different products. The cytotoxicity of the newly synthesized products was studied towards some cancer and normal cell lines, in addition toxicity of compounds was measured and docking of the most active compounds was done. Compounds 6b, 7b, 9, 13a, 13b, 16a, 20b, 20c, 24b, 25 and 26b exhibited optimal cytotoxic effect against cancer tested cell lines. These active compounds were evaluated against c-Met kinase using foretinib as the reference drug where all compounds expressed higher activity than the reference drug. [ABSTRACT FROM AUTHOR]

The chalcone derivatives 3a‐d reacted with either malononitrile or ethyl cyanoacetate in ethanol in the presence of catalytic amount of ammonium acetate in an oil bath at 120°C to give the Knowevenagel condensation products 5a‐h. The latter compounds reacted with hydrazine hydrate and afforded the 4H‐pyrazole derivatives 7a‐h, respectively. The reaction of compounds 7a‐h with ethyl cyanoacetate in dimethylformamide under refluxing condition afforded the cyanoacetamido derivatives 8a‐h, respectively. When compounds 8a‐h reacted with elemental sulfur and either of malononitrile or ethyl cyanoacetate in ethanol containing triethylamine, the thiophene derivatives 9a‐h and 10a‐h, respectively, were obtained. The structure of the newly synthesized compounds was established by the analytical and spectral data. All the newly synthesized compounds were evaluated against the six cancer cell lines: A549, HT‐29, MKN‐45, U87MG, and SMMC‐7721 and H460. Compounds 3c, 5h, 7g, 7h, 8f, 9e, 9g, and 10g were selected to examine their Pim‐1 kinase inhibition activity as these compounds showed high inhibition toward the c‐Met kinase and the tested cancer cell lines. Furthermore, compounds 3b, 3c, 5g, 5h, 7f, 7g, 7h, 8e, 8f, 8g, 8h, 9e, 9f, 9g, 9h, 10g and 10h were selected to be tested for pan‐assay interference compounds analysis (PAINS). Almost all the tested compounds showed zero PAINS alert and can be used as drug compounds in the future. [ABSTRACT FROM AUTHOR]

In this work, thiophene derivatives were synthesized in good yields via multicomponent reaction of isoquinoline, alkyl bromides, activated acetylenic compounds, isothiocyanates, and catalytic amounts of ZnO nanorods (NRs) at room temperature under solvent‐free conditions. This procedure for the synthesis of thiophene derivatives is green, easy, and simple with excellent yield. In addition, DPPH radical scavenging and ferric reduction power experiment has been studied for the evaluation of the antioxidant activity of some prepared thiophenes, for example, 5b, 5d, 5e, and 5f. As outcome, the compound 5d exhibited a noteworthy radical trapping activity and excellent reducing ability than synthetic antioxidants such as butylated hydroxytoluene (BHT) and 2‐tertbutylhydroquinone (TBHQ). Moreover, the antimicrobial activity of some synthesized thiophenes was confirmed by employing the disk diffusion test on Gram‐positive and Gram‐negative bacteria. The obtained results of disk diffusion test showed that compounds 5b, 5d, 5e, and 5f prevented bacterial growth. [ABSTRACT FROM AUTHOR]

Iodination of a series of benzene and thiophene derivatives by potassium dichloroiodate monohydrate was studied with and without a solvent. The liquid substrates tend to be more reactive in water while the solid substrates afford better yields in dichloromethane or under the solvent-free conditions. The 2-substituted thiophenes show good to excellent yields whereas the yield for 3-substituted and 3,4- or 2,4-disubstituted thiophenes and benzene derivatives are significantly lower. The mechanochemical reaction of 5-carbaldehyde-2,2′-bithiophene shows excellent yields, while 2,2′-bithiophene gives practical yields only in dichloromethane. In the case of thiophene and N -acetyl- p -toluidine, electrophilic iodination is accompanied by a small extent of chlorination. [ABSTRACT FROM AUTHOR]

The thiophene core is the most broadly applied constructing blocks to the production of many biomolecules, pharmaceutical drugs,vitamins,also in industrial compounds, in dyes compounds because of its high stability in environment. Thiophene derivatives were synthesized in present study from chalcone compound as a starting material from aldol reaction in first step, followed by cyclization reactions by using various conditions, and this paper involved new reaction for diazonium salts to producing (Sulfide- azo) compounds in same bond for the first time that we termed (Sulfazane) as a first and Novel preparation to this new type of compounds.,the synthesized derivatives were confirmed through numerous spectral techniques (FT.IR,H.NMR,C.NMR), other physic-chemical data for synthesized thiophene derivatives,besides to studying of behavior of compounds in organic solvents and screening tests for efficiency of thiophene derivatives against microbes. [ABSTRACT FROM AUTHOR]

The catalytic C-H silylation of a variety of aromatic heterocycles such as furan, pyrrole and thiophene derivatives with secondary hydrosilanes has been achieved by using an yttrium metallocene complex. This protocol provides an efficient and straightforward way for the synthesis of a series of silylated heteroaromatic compounds containing tertiary silane moieties without the need for an additive or H2 acceptor. [ABSTRACT FROM AUTHOR]

This study aims to design and synthesize a number of novel pyran, thiophene, and pyridine derivatives incorporating thiazole ring and evaluate their antitumor inhibition (μM) as significant anticancer agents. The reactivity of compound 1 [2‐(4‐oxo‐4,5‐dihydrothiazol‐2‐yl)acetonitrile] towards different chemical reagents was described. Furthermore, the reactivity of all the newly synthesized products was evaluated. The most active compounds towards all the three tumor cancer cell lines used such as MCF‐7 (breast adenocarcinoma), NCI‐H460 (non‐small cell lung cancer) and SF‐268 (CNS cancer), and normal fibroblasts human cell line (WI‐38) were compounds 6d, 8, and 10b, which compared with the antiproliferative effects of the reference control doxorubicin. Also, some of the novel compounds indicate higher inhibition than doxorubicin against some of the cancer cell lines used such as 6c (especially towards MCF‐7) and 2b, 6b (especially towards SF‐268). [ABSTRACT FROM AUTHOR]

The reaction of ethyl benzoylacetate with malononitrile in an oil bath at 120°C gave the condensation product 3. The latter compound underwent a series of heterocyclization to give thiophene, thiazole, pyridine, and pyran derivatives. The structures of the synthesized products were established on the basis of analytical and spectral data. The antitumor evaluation of the newly synthesized products against the six cancer cell lines namely human gastric cancer (NUGC and HR), human colon cancer (DLD1), human liver cancer (HA22T and HEPG2), human breast cancer (MCF), nasopharyngeal carcinoma (HONE1), and normal fibroblast cells (WI38) indicated that many compounds expressed high inhibition against the six cancer cell lines. Compounds 3, 8a, 8c, 14b, 16b, 16c, 16d, 19a, 19b, 20a, 22a, 27b, and 28a were the most cytotoxic compounds among the tested compounds. [ABSTRACT FROM AUTHOR]

A series of novel 1,4-pentadien-3-one derivatives containing a thiophene sulfonate group were designed, synthesized, and their antibacterial activities were assessed. Antibacterial bioassays indicated that some of the title compounds exerted significant bioactivities against Xanthomonas axonopodis pv. Citri (Xac), Ralstonia solanacearum (Rs) and Xanthomonas oryzae pv. Oryzae (Xoo). Especially for Xac, the value of minimum 50% effective concentration (EC50) of compound 4-((1E,4E)-5-(3-nitrophenyl)-3-oxopenta-1,4-dien-1-yl)phenylthiophene-2-sulfonate (3k) is 11.0 μg/mL, which is significantly superior to bismerthiazol (BT) (51.6 µg/mL) and thiodiazole-copper (TC) (94.7 µg/mL). Meanwhile, the mechanism of action of compound 3k was confirmed by using scanning electron microscopy (SEM). These results suggested that 1,4-pentadien-3-one derivatives containing thiophene sulfonate group may be considered as activators in the design of antibacterial agents. [ABSTRACT FROM AUTHOR]

The results of studies on the activation of С–Н and С–S bonds of thiophenes and their derivatives by transition metal compounds are summarized. A variety of thiophene-to-metal coordination modes, which depend on a particular metal and its surrounding ligands, are considered, as well as the transformations of thiophene compounds under the influence of transition metal complexes. [ABSTRACT FROM AUTHOR]

Novel chiral bifunctional thiourea derivatives have been synthesised and successfully applied to the intermolecular Morita-Baylis-Hillman (MBH) reaction of an aromatic aldehyde with methyl vinyl ketone (MVK) and to the intramolecular MBH reaction of ω-formyl-enone. The corresponding products were obtained with high enantioselectivities (up to 98% ee). The thiourea organocatalyst derived from a β-amino alcohol gave high enantioselectivities (92% ee) in the intermolecular MBH reaction, whereas the same chiral ligand afforded the corresponding product in high yield (85%) with moderate enantioselectivity (75% ee) in the intramolecular MBH reaction. The use of a thiophene ring-containing thiourea derivative gave high enantioselectivities in the intermolecular and intramolecular MBH reactions (85% and 95% ee, respectively). [ABSTRACT FROM AUTHOR]

Oligothiophene derivatives have been extensively studied as p‐type semiconducting materials in organic electronics applications. This work reports the synthesis, self‐assembly and photophysical properties of acceptor–donor–acceptor (A–D–A)‐type oligothiophene derivatives by end‐group engineering of quaterthiophene (QT) with naphthalene monoimide (NMI) chromophores that are further connected to a trialkoxy benzamide wedge. Conjugation to the NMI units reduces the HOMO–LUMO gap significantly, and consequently the absorption spectrum exhibits a bathochromic shift of about 50 nm compared with QT. Furthermore, extended H‐bonding interactions among the amido groups of the peripheral wedges produce entangled fibrillar nanostructures and gelation in hydrocarbon solvents such as methylcyclohexane, wherein the A–D–A chromophore exhibits typical H‐aggregation. On the contrary, the fact that the same chromophore, lacking only the amido units, does not produce gels or H‐aggregates indicates strong impact of H‐bonding on the self‐assembly. Computational studies revealed the electronic properties of the chromophore and predicted the geometry of a dimer in the H‐aggregate that reasonably matches with the experimental results. Bulk electrical conductivity measurements determined an excellent conductivity of 2.3×10−2 S cm−1 for the H‐aggregated system (OT‐1), which is two orders of magnitude higher than that of the same chromophore lacking the amido groups (OT‐2). [ABSTRACT FROM AUTHOR]

Photochemical oxidative cyclization of 2- and 3-thienylstilbenes (heterostilbenes) containing mono-, di- and trimethoxy groups in the benzene ring or heterocyclic fragment results in the formation of isomeric thieno-annelated polycyclic aromatic compounds demonstrating optical properties that differ from those of initial stilbene derivatives. The structures of cyclic products were evaluated via1H and 13C NMR, HRMS, elemental analysis and X-ray crystallography. The research was aimed to study the effect of substituents in stilbene derivatives of thiophene as well as the position of the styryl fragment in the thiophene nucleus on the occurrence of photocyclization reactions. [ABSTRACT FROM AUTHOR]

The thermodynamic characteristics of adsorption (TCA) of thiophene and its derivatives are determined under the conditions of equilibrium gas adsorption chromatography (GAC) on columns with graphitized thermal carbon black (GTCB) of Carbopack C HT grade. It is shown that the TCA values ​​ depend largely on the number and nature of the substituents in the main structural fragment. It is found that the surface of the GTCB is characterized by low structural selectivity for positional isomers in the series of thiophene derivatives. The effect of polar retention of an adsorbate on graphite from the gas phase due to additional intermolecular specific interactions of polar groups of the adsorbate with an easily polarizable surface of the base face of graphite is established and studied. Conclusions are reached on the applicability of the two-dimensional ideal gas model for describing the mobility of strongly polar molecules of thiophene derivatives on surfaces of graphite, and on the considerable limitations of this model when applied to the adsorption of thiophene molecules, along with its methyl and halogen derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of novel thieno[3,2–b]thiophene-fused BODIPY derivatives with water-soluble groups were designed, synthesized and evaluated. • These compounds exhibited NIR absorptions (∼660 nm) and high molar extinction coefficients (0.73 × 105-1.42 × 105 M−1·cm−1). • These compounds possessed good singlet oxygen generation and photodynamic anti Eca-109 cancer cells abilities. • Compound II 4 could be well uptaked by Eca-109 cells, and showed much better photodynamic efficiency both in vitro and in vivo than Temoporfin. To discover new photosensitizers with long wavelength UV–visible absorption, high efficiency, and low side effects for photodynamic therapy, here, a series of novel thieno[3,2–b]thiophene-fused BODIPY derivatives were designed, synthesized and characterized. These compounds had a distinct absorption band at 640–680 nm, fluorescence emission at 650–760 nm, and good solubility with anti-aggregation effects. These new compounds possessed obvious singlet oxygen generation ability and photodynamic anti-Eca-109 cancer cells activities in vitro. Among them, compound II 4 could be well uptaked by Eca-109 cells, and result in the apoptosis after laser irradiation, and have outstanding photodynamic efficiency both in vitro and in vivo. Therefore, II 4 could be considered as a potential photosensitizer drug candidate for PDT and photo-imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • The perovskite's VB and CB frontier molecular orbitals are well matched with the three compounds (T 16 , T 17 , and T 18). • The solubility of T 18 is improved by the presence of azomethine groups, which also causes a red shift in the absorption wavelength. • For usage as the active layer of an organic solar cell, T 18 is ideally suited. DFT and TDDFT approaches were used to design three (T 16,17,18) molecules based on 4,4′-dimethoxy-2,2′-bithiophene core to explore the influence of substitution of triphenylamine (TPA) fragment by methoxy groups, and introduction of azomethine π-bridges on the optoelectronic properties of hole transporting materials for perovskite solar cells (PSCs) or as donor for organic solar cells (OSCs). To shed light on the efficiency, stability, and solubility several physicochemical parameters were computed in dichloromethane solvent. All designed molecules show appropriate frontier molecular orbital levels, which facilitates effective hole transfer from the perovskite materials to the HTMs in the hole-transporting layer in PSC devices. They all show good efficiency and pore-fillings and are stable and soluble in dichloromethane. Electron-hole pairs can easily dissociate into free charge carriers, especially for T 16 and T 17 ; consequently, improve short-circuit current densities and facilitate hole transport. It is also advised to use T 18 which includes azomethine bridges as a donor with a non-fullerene Y6 acceptor to create effective OSCs because it exhibits high open circuit voltage, fill factor and low gap energy. [ABSTRACT FROM AUTHOR]

The discovery of new photosensitizer drugs with long wavelength Uv–vis absorption, high efficiency and low side-effects is still a challenge in photodynamic therapy. Here a series of novel mes o-substitutedphenyl thieno[3,2-b]thiophene-fused BODIPY derivatives were designed, synthesized and characterized. All these compounds have strong absorption at 640–680 nm and obvious fluorescence emission at 650–760 nm. They exhibited high singlet oxygen generation ability and significant photodynamic efficiency against Eca-109 cancer cells. Compounds II 4 , II 6 , II 9 , II 10 and II 13 could generate intracellular ROS and induce cell apoptosis after laser irradiation, which displayed superior photodynamic efficiency against Eca-109 cells than Temoporfin in vitro and in vivo. Among them, compound II 4 specifically exhibited excellent anti-tumor efficacy, and could be selected as a new drug candidate for PDT. [Display omitted] • A series of novel TT-BODIPY derivatives were designed, synthesized and evaluated. • They exhibited NIR absorptions (650 nm) and high molar extinction coefficients. • They displayed good singlet oxygen generation and anti-tumor (Eca-109) abilities. • Compound II 4 showed much better photodynamic activity than Temoporfin. [ABSTRACT FROM AUTHOR]

• Two thiophene derivatives as the π-bridge are developed for NLO materials by altering the aromatic bridge of reference molecule M1. • Compared to the reference molecule M1, all newly designed chromophores have a narrower band gap, greater hyperpolarizability (β tot), and red-shifted absorption spectra. • The modifications of π-spacer units of reference chromophore M1 effect studied chromophores' (NLO) properties. • The β tot values of all chromophores are higher than those of the urea molecule (β tot) value of urea = 43 a.u). Three metal-free organic compounds based on N,N-Diethylaniline as a donor, and 2-(3-cyano-5,5-dimethylfuran-2(5H)-ylidene)malononitrile as an acceptor of electrons with the D-π-A architecture were investigated theoretically using DFT, LC-DFT and TD-DFT techniques for future usage as NLO materials. The effect of changing the π-linker of the parent compound M1 on the electronic, photophysical characteristics and the nonlinear optical response has been extensively studied and discussed. M1-M3 exhibit a band gap (E gap) in the 1.51 to 1.85 eV range with λabs of 600 to 900 nm. The results indicate that M3 possesses excellent polarization characteristics of the first total hyperpolarizability β tot at 15.48 × 10–28 esu associated with a low E gap at 1.51 eV. Examining the NBO, the DOS, and the TDM reveals that charge separation occurred following photoexcitation, and the electrons were migrated from the donor to the acceptor group. [Display omitted] [ABSTRACT FROM AUTHOR]

• Introducing an organic sulfur-containing group in catalyst, except for –SO 3 H groups. • Regulating content of thiophene groups by adjusting proportion of aromatic monomers. • The introduction of thiophene groups increases –SO 3 H group densities of catalyst. • Thiophene groups enhance the CH- π interaction between catalyst and cellulose. Two different aromatic monomers, naphthalene and benzothiophene, were ingeniously selected to prepare a solid acid with thiophene groups, which can selectively convert cellulose into glucose. The content of thiophene groups in the solid acids was regulated by adjusting the proportion of aromatic monomers. The effect of thiophene groups on physico-chemical structures and catalytic activity of solid acids was discussed. The experiment results indicate that the sulfur content in solid acids was up to 19.57 wt%. The introduction of thiophene groups increased –SO 3 H group density and adsorption capacity by 30.99 % and 64.36 %, respectively. These positive changes result in excellent catalytic activity of solid acids. The cellulose conversion rate and glucose selectivity reached 78.9 % and 97.1 % respectively at 150 °C and 7 h. [Display omitted] [ABSTRACT FROM AUTHOR]

Liquid crystalline organic semiconductors have garnered significant attention in the realm of organic thin-film transistors (OTFTs) due to their inherent controllability of phase and electrical properties with temperature variations. Typically, liquid crystalline semiconductors possess distinct structures comprising rigid anisotropic cores and flexible chains. Here, we sought to identify liquid crystalline semiconductor materials by appending a thiophene ring and octyl chain to the anisotropic 6-(thiophen-2-yl)benzo[ b ]thiophene (TBT) backbone. Among the investigated TBT derivatives, the compound featuring additional thiophene ring and octyl chains on both sides exhibited pronounced liquid crystalline characteristics, specifically the SmE phase. The optical, thermal, and electrical characteristics as well as thin film properties of the TBT derivatives were investigated. The TBT compound was employed through solution-shearing as an active layer for top-contact/bottom-gate OTFTs. The liquid-crystalline TBT (2,6-bis(5-octylthiophen-2-yl)benzo[ b ]thiophene) thin film annealed at low temperature (30 °C) showed hole mobility as high as 0.025 cm2/Vs and current on/off ratio of > 106. This results in a significant enhancement by an order of magnitude compared to the sample annealed at 70 °C in the SmE phase, and nearly a two-fold improvement compared to the performance observed in the sample annealed at 130 °C in the transition phase. The utilization of the TBT derivative as a p-channel material represents a significant step toward the development of novel liquid crystalline semiconductors. [Display omitted] • Novel 6-(thiophen-2-yl)benzo[ b ]thiophene (TBT) derivatives were synthesized. • The effect of the end-capping group on TBT-based semiconductors was investigated. • The liquid crystalline phases and characteristics were examined. • Developed compounds were employed as active layers for OFETs. • The liquid crystalline compound exhibited the highest mobility at the crystal phase. [ABSTRACT FROM AUTHOR]

A series of hydroxy thiophene-conjugated benzothiazole derivatives (HTB s) was prepared to investigate their fluorescence emission behaviors and capability to selectively stain subcellular organelles for fluorescence imaging. The HTB derivatives exhibited excited-state intramolecular proton transfer (ESIPT) and intramolecular charge transfer (ICT) behaviors, according to their molecular structure. Subtle changes in the molecular structure of the HTB influenced its response to changes in the surrounding environment, such as the solvent polarity and/or pH. In vitro cellular imaging experiments revealed that HTB A (5-(benzo[d]thiazol-2-yl)-[2,2′-bithiophen]-4-ol) could selectively stain mitochondria. In contrast, HTB B -CO 2 Et (ethyl 5'-(benzo[d]thiazol-2-yl)-3′-hydroxy-[2,2′-bithiophene]-5-carboxylate), which contains a regioisomeric hydroxy thiophene unit with an electron-withdrawing ethyl ester group, showed the capability to stain lipid droplets (LDs) in living cells. When the hydroxyl group in HTB B -CO 2 Et was protected with a benzyl group, effective staining of LDs in live cells was achieved. Thus, we successfully obtained an effective fluorescent probe. Collectively, the results indicated that small structural changes resulted in substantial changes in the intracellular localization and in vitro imaging ability of the prepared compounds. [Display omitted] • Hydroxy thiophene-conjugated benzothiazole derivatives (HTB s) were synthesized. • HTB s exhibited polarity-dependent bright emission due to ESIPT and ICT. • The structural change of HTB s enabled selective staining of mitochondria and lipid droplets. [ABSTRACT FROM AUTHOR]

A new thiophene-substituted terpyridine derivative has been prepared and characterized. This ligand features a thiophene heterocycle (as an electrochemically polymerizable unit) as well as two chlorine atoms for further functionalization.

A variety of thienoquinolones were synthesized from readily accessible thiophene derivatives by regioselective acylations and subsequent two‐fold Buchwald–Hartwig–amination. This cyclization allows a convenient synthesis of biologically and pharmaceutically important thienoquinolones. Several thienoquinolones were synthesized in good to very good yields. The optical properties of the products were studied in detail. [ABSTRACT FROM AUTHOR]

π-Acidic triangular silver(I) 3,5-bis(trifluoromethyl)pyrazolate (Ag3pz3) can form 1 : 1 adducts with dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (DMDBT), benzothiophene (BT), and 2,5-dimethylthiophene (DMT), which are stabilized by weak Ag⋯S and Ag⋯C contacts and sometimes by π–π stacking and, therefore, may represent a weak interaction model for some adsorptive desulfurization processes. [ABSTRACT FROM AUTHOR]

Multifunctional pyrazole derivative, i.e. 3-amino-1-(5-hydroxy-3-methyl-1H-pyrazol-4-yl)-1H-benzo[f]chromene-2-carbonitrile (PBCC) has been synthesized and characterized. To shed light on various properties of interests, the ground state geometry was optimized by adopting Density Functional Theory (PBE/TZ2P). The effect of different functionals on the absorption wavelengths was studied by using Time-Domain DFT (TDDFT), e.g. GGA functional PBE, hybrid functionals B3LYP and PBE0, rang separated functionals CAM-B3LYP, LCY-PBE and CAMY-B3LYP, Dispersion Corrections PBE-D3 and B3LYP-D3. Among all these functionals PBE and PBE-D3 were found to be good choices which reproduced the absorption spectra of the PBCC. With the aim to enhance the electro-optical, charge transfer and photovoltaic properties, five new derivatives were designed by di-substituting the –F, –Cl, –Br, –COOH and –CN at benzochromene moiety. The electron injection barrier, band gap alignment and related calculated photovoltaic parameters revealed that PBCC and its newly designed derivatives would be proficient to be used in photovoltaic devices. These compounds can be used as donor materials in dye-sensitized solar cells (DSSCs) with favorable type-II band alignment. Moreover, PBCC and most of its derivatives might also be good choice as efficient acceptors with poly(dithieno[3,2-b:2,3-d]pyrrole thiophene) (PDTPr-T) and donor materials with Phenyl-C61-butyric acid methyl ester (PC61BM) in organic solar cells. [ABSTRACT FROM AUTHOR]

A series of pyrazole-thiophene derivatives exhibiting good Akt inhibitory activities were obtained on the basis of conformational restriction strategy, leading to the discovery of compound 1d and 1o which showed excellent in vitro antitumor effect against a variety of hematologic cancer cells and their potential of inducing apoptosis, blocking the cell cycles at S phase and significantly inhibiting the phosphorylation of downstream biomarkers of Akt kinase of cancer cells. Amongst, compound 1o also exhibited good PK profiles and inhibited about 40% tumor growth in MM1S xenograft model. Compound 1o might be a potential candidate for further development. Image 1 • Compound 1d and 1o with good Akt inhibitory activities were obtained on the basis of conformational restriction strategy. • Compound 1d and 1o showed excellent in vitro antitumor effect. • Compound 1o exhibited good PK profiles and a 40% tumor growth inhibition in MM1S xenograft tumor model. [ABSTRACT FROM AUTHOR]

Phenacylbromide derivatives constitute a multilateral group of precursors for the synthesis of numerous heterocycles of organic compounds. Briefly, 5‐(2‐bromo‐acetyl)‐substituted‐thiophene derivative has been used as a synthon for synthesis of new thiophene‐containing compounds through the reaction with nucleophilic nitrogen compounds and thioamides. The suggested structures of the newly synthesized thiophene compounds were confirmed and assured with different spectroscopic tools and with CHN elemental analysis. Additionally, the antimicrobial activity of these thiophene compounds was recorded to investigate their potency against various types of bacteria and fungi. Results showed that these compounds exhibit significant inhibitory activity against the growth of tested bacterial and fungal strains and that some derivatives were more potent than the employed reference drugs. [ABSTRACT FROM AUTHOR]

The synthesis, characterisation and application as electron-acceptors in organic photovoltaic cells of new [1,2,5]thiadiazolo[3,4-g]quinoxaline-based small molecules with oligo(ethylene oxide) solubilising groups and tunable optical bandgaps are reported. A new p-type polymer consisting of a polythiophene derivative substituted with analogous solubilising groups was also synthesised to perform as a donor, in combination with the small molecules, for bulk-heterojunction solar cells using ethanol/anisole mixtures as low toxic solvents to process the active blends. Comparison of the structural, electrochemical and photophysical properties of the small molecules elucidated on the structural dependence of their optical bandgaps, ranging from 1.31 to 2.25 eV. The active layers composed of the polythiophene donor and the small molecules showed well-intermixed morphologies, and the best performing blends showed a fibrillar-type morphology, indicative of more ordered molecular packings. Blends processed from the 50 : 50 (v/v) mixture of ethanol and a low toxic solvent, anisole, yielded low power conversion efficiencies of 0.39% in non-optimized organic solar cells. Although the efficiencies are low, these are the first reported results of OSCs with active layers composed of non-fullerene acceptors processed from ethanol-based solvent formulations. This study provides guidelines for the design of non-fullerene acceptors for the fabrication of OSCs processed from environmentally friendly solvents. [ABSTRACT FROM AUTHOR]

In an attempt to establish novel candidate with promising anticancer activity, two derivatives of (benzo[d]thiazol‐2‐yl)thiophene backbone 1 and 14 were synthesized, and they further reacted with various chemical reagents to afford the corresponding substituted thiophene derivatives 6, 8, 10, 15, 17, and 20, thieno[3,2‐d]pyrimidine derivatives 2–5, 7, 9, 16, 21, 23, and 24, thieno[3,2‐b]pyridine derivatives 11–13, and thieno[3,2‐e][1,4]oxazepine derivative 18. Structures of prepared compounds were affirmed via spectral and elemental data. Among the obtained compounds, seven derivatives 2, 3, 4, 5, 11, 12, and 13 were chosen by National Cancer Institute, USA. Such compounds were screened for their antitumor activity versus 60 cancer cell lines in one‐dose (10 μmol) screening assay. The outcomes showed that all selected compounds exhibited moderate to high anticancer activity towards many cancer cell lines among which compounds 5 and 11 exerted potent antitumor activity against numerous malignant growth cell lines particularly Ovarian Cancer IGROV1. [ABSTRACT FROM AUTHOR]

This work presents the study of the adsorption affinity of biobased adsorbent prepared by pyrolysis of rice husks (PRH) toward thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) in single and mixed solutions in a batch mode using a model fuel and real diesel. A degree of desulfurization higher than 40% is observed in case of an initial sulfur concentration in the fuel not higher than 1000 ppm. The adsorption selectivity of PRH from single solutions of the three aromatic sulfur heterocycles (ASHs) decreases following the line: T > BT > DBT. The theoretical equilibrium adsorption capacity of PRH in regard to the three sulfur compounds adsorption is determined using the adsorption isotherms of Langmuir, Freundlich, Dubinin-Radushkevich and Temkin. The calculated values of the thermodynamic parameters, such as the Gibbs energy, ΔG0, the entropy, Δ0, and the enthalpy, ΔH0, indicate that the adsorption in PRH-ASHs-fuel system proceeds at normal and high temperature values through simultaneous physical and chemical interactions. [ABSTRACT FROM AUTHOR]

We have synthesized and characterized fluorene derivatives with alkylated thiophene as solution-processed organic semiconductors for organic field-effect transistor. HOMO/LUMO energy levels of the developed materials were tuned via different electron-acceptors. Organic field-effect transistor fabricated from dicyanovinylene-functionalized fluorine derivative with octyl thiophene as the side group exhibited n-channel characteristic with electron mobility of 0.0055 cm2/Vs and current on/off ratio ∼106. Film surface morphology and texture were correlated with the corresponding device performance. [ABSTRACT FROM AUTHOR]

In this study, the copper catalyzed amination reactions of 3,4-dibromothiophene with some primary, cyclic and acyclic secondary amines were investigated to prepare novel electron rich-thiophenes which are expected to be used as novel N-containing donor type monomer candidates for conductive polymers. In order to obtain better yields, this S N Ar type amination reaction was optimized by studying the reaction conditions, such as the copper catalyst, the type of copper source, the presence of a base and the type of the solvent on the model reaction between 3,4-dibromothiophene and n-butylamine. A variety of 3,4-(N,N′-dialkylamino)thiophenes and 3-(N-alkylamino)thiophenes were synthesized in moderate yields under the optimized reaction conditions. In addition, two new heterocyclothiophene derivatives were successfully prepared from the cyclization reaction of 3,4-bis(N-butylamino)thiophene. The characterization of the isolated alkylaminothiophenes was performed by FTIR, 1H and 13C NMR, GCMS and elemental analysis. The theoretical calculations for all alkylaminothiophenes were executed by using the DFT/B3LYP/6-311+G(2d,p) approach. Image 1 • Some alkylaminothiophenes from 3,4-dibromothiophene were synthesized. • Two novel heterocyclothiophenes were prepared from 3,4-bis(N-butylamino)thiophene. • DFT calculations for all alkylaminothiophenes were performed. • The theoretical results were compared with the experimental spectroscopic data. [ABSTRACT FROM AUTHOR]

A rapid and highly efficient 1,3‐dipolar [3 + 2] cycloaddition of nonstabilized azomethine ylides generated in situ with benzo[b]thiophene 1,1‐dioxides as the dipolarophiles has been developed. The efficient method affords tricyclic pyrrolidine‐fused benzo[b]thiophene 1,1‐dioxide derivatives in high to excellent yields (up to 99%) with excellent diastereoselectivities (up to >25:1 dr) under mild reaction conditions. The structure of a typical product was confirmed by X‐ray crystallography. [ABSTRACT FROM AUTHOR]

Electrochemical studies on a series of new conjugated oligothiophene derivatives are reported. The molecular architectures (D−A and A−D−A) of these compounds present different donor cores (thiophene, bithiophene) with different numbers of 3‐octylthiophene units (that act as π‐bridge and solubilizing components). The acceptor end groups adopted were, in all the cases, ethyl cyanoacrylate units. The results from voltammetric experiments confirm the close relationship between the structure of these oligothiophenes and their electrochemical behavior. Furthermore, we carried out quantum mechanical calculations to be able to obtain the HOMO/LUMO characteristics of some of our compounds in order to confirm our hypotheses on their electrochemical behavior. Moreover, the roles of the oligothiophene backbone and the ethyl cyanoacrylate group in cyclic voltammetry were elucidated by carrying out two different electrolyses at anodic and cathodic peak potentials. In particular, we were successful in the anodic dimerization of a tetrathiophene (D−A) to an octithiophene (A−D−A) (in high yield) with a considerable shortening of the chemical synthesis. [ABSTRACT FROM AUTHOR]

Synthesis of three photovoltaic polymers PFBT-HH, PFBT-HF and PFBT-FF based on benzothiadiazole derivatives and fluorene ring was carried out by direct arylation reaction. The polymers were designed to have a donor–π–acceptor –(D–π–A)n– structure, PFBT derivatives were synthetized employing similar reaction conditions to evaluate the effect of fluorine atoms into the acceptor moiety. For synthesis of PFBT-polymers via direct arylation reaction, the presence of fluorine atoms promotes materials with lower molecular weight and with deep HOMO and LUMO energy levels. An expected increment of photochemical stability with the substitution of fluorine atoms on polymers was observed for its pristine films, and the reduction of polymers photodegradation due to presence of PC61BM fullerene derivative. Photovoltaic characteristics of PFBT-polymers were evaluated into Polymer Solar Cell with bulk- heterojunction architecture fabricated under the configuration glass/ITO/PEDOT:PSS/polymer:PC61BM/PFN/FM. Devices were fabricated at room atmospheric conditions, using an easy-to-manufacture superior electrode (FM = Field's metal) which was free vacuum deposited by melting it about 90 °C, average power conversion efficiencies of 2.3, 1.1 and 1.2% were reached for high molecular weight fractions of polymers PFBT-HH, PFBT-HF and PFBT-FF, respectively. [ABSTRACT FROM AUTHOR]

A series of polycyclic aromatic hydrocarbons (PAHs), consisting of two pairs of BN units, have been designed and their synthesis has been achieved by electrophilic C−H borylation. Two conjugation extension directions can be found in these B2N2‐embedded PAHs. The B2N2‐containing backbone with shorter effective conjugation length is isoelectronic with diaryl‐fused anthracene, whereas the second derivative, with longer effective conjugation length, is isoelectronic with bis(trans‐arylvinyl)benzene. By incorporating different aryl groups, i.e. furyl, thienyl, benzo[b]furyl, and benzo[b]thienyl groups, into the two crossed directions of the B2N2‐embedded PAHs, their electronic and optical properties have been comparatively investigated by photophysical, electrochemical, and theoretical approaches. It is found that both the substituents and their conjugation extension directions have significant effects on the aromatic and photophysical properties of the B2N2‐embedded PAHs. The conjugation extension in the shorter backbone is more pronounced on the effective conjugation length than the longer backbone. Moreover, all the B2N2‐embedded PAHs behave as both Lewis acids and Lewis bases, and reversible photoluminescence switching can be observed by simply neutralizing the added Lewis acid or Lewis base. [ABSTRACT FROM AUTHOR]

Widely distributed in nature, coumarins are one of the more common and well-known representatives of a flavonoid class. Nevertheless, they exhibit a strong and broad variety of biological activities. In the present research study, we describe a series of naphthalene and quinoline, furan and thiophene derivatives fused with a coumarin scaffold. The compounds have been interpreted by IR, GCMS, and NMR spectral studies and evaluated in vitro for their antimicrobial activities against four different pathogenic bacterial strains such as E. coli, P. aeruginosa, K. pneumonia, S. aureus and S. faecalis and fungal strains such as A. flavus, A. fumigatus and B. albicans. The coumarins fused with thiophene ring exhibit promising anti-microbial properties. [ABSTRACT FROM AUTHOR]