Thiophene Groups Research Articles

Discovery of 5-aryl-3-thiophen-2-yl-1H-pyrazoles as a new class of Hsp90 inhibitors in hepatocellular carcinoma

Although hepatocellular carcinoma (HCC)-related mortality has increased over the past decades, treatment options are still very limited, underlining the need for developing new therapeutic strategies. The molecular chaperone heat shock protein 90 (Hsp90) plays a key role in post-translational maturation of many oncogenic client proteins that are important for survival and proliferation of cancer cells. Thus, inhibitors of Hsp90 are promising targets for many cancer types. In this study, 15 diarylpyrazole compounds were screened against MCF7 and HepG2 cell lines. Compound 8, which contained a thiophene group, demonstrated the highest antiproliferative activity against HepG2 cells having an IC50 of 0.083 μM. Four additional diarylpyrazoles, each containing a thiophene group, were prepared and screened for antiproliferative activity. None of these four compounds exhibited superior activity to compound 8 on HepG2 cells. Therefore, compound 8 was selected for further in vitro assays. Cell cycle arrest was observed at the G2 phase in compound 8-treated cells. Compound 8 also caused a 7.7-fold increase in caspase-3. These results confirm the apoptotic effect of compound 8 on HepG2 cells. Moreover, compound 8 inhibited Hsp90 (IC50 = 2.67 ± 0.18 µM) in an in vitro assay and caused a 70.8% reduction in Hsp90 levels in a HepG2 cell-based assay. Additionally, compound 8 caused significant reduction in the levels of Hsp90 client proteins (Akt, c-Met, c-Raf, and EGFR) and a 1.57-fold increase in Hsp70. Molecular docking studies were also performed to predict the binding mode of compound 8 and followed by molecular dynamics simulations to give further insights into the binding mode of 8.

Synthesis, electrochemistry, and electrochromic properties of branched thiophene polymers with different conjugation lengths

Here the authors designed and synthesized three branched thiophene polymers with different effective conjugation lengths of thiophene groups, pTPBT, pTPTT, and pTPQT, mainly based on bithiophene, trithiophene, and quadruple thiophene. The electrochemical curves and theoretical calculation results reflect that the oxidation potential of polymers decreased gradually as the conjugation lengths of thiophene groups increased, which is favorable for the appearance of electrochromism. Electrochromic properties demonstrate that pTBTT displays no electrochromism, pTPTT exhibits an unstable one, while pTPQT shows an obvious stable electrochromism between yellow‐orange and blue‐violet colors. These results indicate that thiophene polymers with effective electrochromism should be the smallest conjugation length of quadruple thiophene at least. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2340–2348

Tuning of optoelectronic properties of triphenylamines-based donor materials for organic solar cells

In the present study, four molecules have been designed by substituting various acceptor moieties around the triphenylamine donor moiety like 2-cyano acrylic acid (R), 2-methylene malonitrile (M1), 2-cyano acrylic acid methyl ester(M2), 2-(2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M3), 2-(6,7-difluoro-2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M4), respectively. CAM-B3LYP/6-31G (d, p) level of theory by using density functional theory (DFT) has been used for the investigation of optoelectronic properties of four new triphenylamine (TPA)-based donor materials (M1–M4) for organic solar cells. In comparison with the recently reported reference molecule, the optoelectronic properties of designed molecules were evaluated. M4 showed absorption maxima at 520[Formula: see text]nm due to extended conjugation with bridged thiophene group. Results of reorganization energy calculations also favor M4 exhibiting highest transfer rate of hole as depicted from its low reorganization energy of hole ([Formula: see text].

Synthesis of aromatic substituted B ← N embedded units with good stability and strong electron-affinity

Two chemically stable B ← N embedded units were synthesized, namely, BNIDT-Ph and BNIDT-Th, with aromatic phenyl (Ph) or thiophene (Th) groups, respectively, attached to the four coordination boron (B) atom. Single crystal data revealed that BNIDT-Ph and BNIDT-Th show obvious π-π interactions (3.83 vs. 3.79 Å) and B ← N dipole-dipole interactions (6.51 vs. 6.67 Å). BNIDT-Ph and BNIDT-Th exhibit strong electronic affinities of 3.70 and 3.81 eV, respectively. Fluorescence quenching was found between PBDB-T and the B ← N embedded molecules in solution, indicating exciton dissociation. These B ← N embedded molecules are potentially useful to further construct novel n-type semiconductors.

Experimental and theoretical studies of imidazole based chemosensor for Palladium and their biological applications

An imidazole derivative (probe L1) bearing a thiophene group was developed as an ON-OFF fluorescent chemosensor for palladium ions. The UV–vis absorption and fluorescence spectral behavior of probe L1 towards various cations were investigated in HEPES buffer aqueous solution. The absorbance intensity of probe L1 considerably enhanced whereas the fluorescence emission intensity was quenched in the presence of Pd2+ ions, while the presence of other metal ions had no notable interference. The stoichiometry of the complex was determined using Job’s plot and a plausible recognition mechanism of probe L1 and Pd2+ is proposed. Density Functional Theory (DFT) calculations were used to study the electronic properties and to optimize the structure on the selectivity of Pd2+ ions and are correlated with the experimental results. The intracellular Pd2+ ion detection in living cells was performed using probe L1 on brine shrimp nauplii (Artemia salina) up to 20 μg/mL.

Artificial Thiophdiyne Ultrathin Layer as an Enhanced Solid Electrolyte Interphase for the Aluminum Foil of Dual-Ion Batteries.

In this study, we design a novel carbon-based material containing thiophene and acetylenic linkers as functional groups named thiophdiyne (Thi-Dy) and apply it as an ultrathin artificial protective layer for the commercially available aluminum (Al) foil of dual-ion batteries (DIBs). The Thi-Dy films can be grown easily and directly on the Al foil through a mild Glaser-Hay coupling reaction. The as-proposed thiophene and acetylenic linker functional groups in Thi-Dy layers act as energetic active sites for the effective fabrication of a stable hybrid solid electrolyte interphase (SEI) during the electrochemical process, which is revealed through the ex situ measurement. The Thi-Dy-enhanced SEI layer contributes to offer a more effective and regulated lithium intercalation and diffusion pathway and delay the pulverization and huge volume expansion of the Al-Li alloy during long cycles, which are confirmed by the improvement on the cyclic stability of DIBs. Those studies are expected to provide novel thiophene-containing functional materials and mass-produced surface modification approach for metal anode protection, which will promote the research for the next-generation rechargeable battery.

Synthesis and Properties of Benzodithiophene-Based Donor-Acceptor Metallo-Supramolecular Polymers

Two new conjugated donor-acceptor (D-A) supramolecular building blocks, which contain benzo[1,2-b:4,5-b′]dithiophene (BDT) electron-donating cores modified with alkoxy (BDT-OR) or thiophene (BDT-Th) groups and electron-accepting 2,2′:6′,2″-terpyridine moieties, were synthesized via Pd-catalyzed Stille coupling. Under the introduction of transition metal ion Ru2+, the novel metallo-supramolecular polymers PBDT-OR and PBDT-Th were obtained by self-assembly polymerization of the monomeric building blocks BDT-OR and BDT-Th, respectively. The resulting polymers exhibitbroad absorption band from 300 to 600 nm. The embedding of the transition metal ions Ru2+ into the backbones of the supramolecular polymers increases the electron-withdrawing capacity of the terpyridine moieties. Consequently, the absorption bands of both PBDT-OR and PBDT-Th exhibit red-shift at the longer wavelength compared with the corresponding monomeric building blocks, 622 nm for PBDT-OR and 625 nm for PBDT-Th, which results from intramolecular charge transfer (ICT). The LUMO energy levels of PBDT-OR and PBDT-Th are similar, −3.44 and −3.43 eV, respectively, while their HOMO energy levels are different, −5.25 and 5.17 eV, respectively, due to distinct electron-donating abilities of the BDT cores modified with alkoxy and thiophene groups. PBDT-OR and PBDT-Th show reduced electrochemical energy gaps, 1.81 and 1.74 eV, respectively. Meanwhile, the resulting polymers PBDT-OR and PBDT-Th are thermally stable under 300 and 389 °C, respectively.

Ultra-high resolution imaging of thin films and single strands of polythiophene using atomic force microscopy

Real-space images of polymers with sub-molecular resolution could provide valuable insights into the relationship between morphology and functionality of polymer optoelectronic devices, but their acquisition is problematic due to perceived limitations in atomic force microscopy (AFM). We show that individual thiophene units and the lattice of semicrystalline spin-coated films of polythiophenes (PTs) may be resolved using AFM under ambient conditions through the low-amplitude (≤ 1 nm) excitation of higher eigenmodes of a cantilever. PT strands are adsorbed on hexagonal boron nitride near-parallel to the surface in islands with lateral dimensions ~10 nm. On the surface of a spin-coated PT thin film, in which the thiophene groups are perpendicular to the interface, we resolve terminal CH3-groups in a square arrangement with a lattice constant 0.55 nm from which we can identify abrupt boundaries and also regions with more slowly varying disorder, which allow comparison with proposed models of PT domains.

Controlling the magnetic exchange coupling in hybrid heterojunctions via spacer layers of π -conjugated molecules

Mastering and understanding the magnetic couplings between magnetic electrodes separated by organic layers are crucial for developing new hybrid spintronic devices. We study the magnetic exchange interactions in organic-inorganic heterojunctions and unveil the possibility of controlling the strength of the magnetic exchange coupling between two ferromagnetic electrodes across $\ensuremath{\pi}$-conjugated molecules' ($\ensuremath{\alpha}$-sexithiophene or para-sexiphenyl) ultrathin film. In $\mathrm{F}{\mathrm{e}}_{3}{\mathrm{O}}_{4}/\ensuremath{\pi}$-conjugated molecules/Co magnetic tunnel junctions, an antiferromagnetic interlayer exchange coupling with variable strength is observed according to the nature of the aromatic rings (thiophene or phenyl groups). The underlying physical mechanism is revealed by ab initio calculations relating the strength of magnetic coupling to the spin moment penetration into a molecular layer at the molecule/Co interface. The prospect that magnetic coupling between two ferromagnetic electrodes can be mediated and tuned by organic molecules opens different perspectives in the way magnetization of organic tunnel junctions or spin valves can be driven.

The Critical Role of Electron‐Donating Thiophene Groups on the Mechanical and Thermal Properties of Donor–Acceptor Semiconducting Polymers

AbstractOrganic semiconducting donor–acceptor polymers are promising candidates for stretchable electronics owing to their mechanical compliance. However, the effect of the electron‐donating thiophene group on the thermomechanical properties of conjugated polymers has not been carefully studied. Here, thin‐film mechanical properties are investigated for diketopyrrolopyrrole (DPP)‐based conjugated polymers with varying numbers of isolated thiophene moieties and sizes of fused thiophene rings in the polymer backbone. Interestingly, it is found that these thiophene units act as an antiplasticizer, where more isolated thiophene rings or bigger fused rings result in an increased glass transition temperature (Tg) of the polymer backbone, and consequently elastic modulus of the respective DPP polymers. Detailed morphological studies suggests that all samples show similar semicrystalline morphology. This antiplasticization effect also exists in para‐azaquinodimethane‐based conjugated polymers, indicating that this can be a general trend for various conjugated polymer systems. Using the knowledge gained above, a new DPP‐based polymer with increased alkyl side chain density through attaching alky chains to the thiophene unit is engineered. The new DPP polymer demonstrates a record low Tg, and 50% lower elastic modulus than a reference polymer without side‐chain decorated on the thiophene unit. This work provides a general design rule for making low‐Tg conjugated polymers for stretchable electronics.

Electrochromic properties of multifunctional conductive polymer based on naphthalene

Conductive polymers are high-tech materials with high energy efficiency, bright colors, compatible with ambient conditions and superior optical properties. The properties of the polymer vary depending on the properties of the monomer used in polymer synthesis. For this reason, the use of multifunctional new monomers with high π-electron density and branching, containing different functional groups, is important in the formation of different types of conductive polymers. In this study, a new monomer suitable for double-sided polymerization on the thiophene groups in the center with the naphthalene molecule has been synthesized (DPN) and polymer P(DPN) has been obtained via this new monomer. P(DPN) is very stable and has the best optical properties. Also it is a special material with the potential to be used for sensor studies with amide groups and active amine protons that can be derivated.

Potentially self-dopable poly(3-hexylthiophene) block copolymers/carbon nanotube nanocomposites for enhanced processibility and electrical properties

Development of new hole-transport layer (HTL) materials for organic photovoltaic (OPV) applications is one crucial issue to mitigate such limitations of low power efficiency, processibility, and stability derived from poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a common HTL material. To this end, poly(3-hexylthiophene) (P3HT)-based diblock copolymers including the different ratios between polystyrene (PSty) or/and poly(neopentyl styrene sulfonate) (PNSS) as a second block segment were designed and then used for incorporating with single wall carbon nanotubes (SWCNTs) to form potentially self-dopable nanocomposites. The structure of fabricated P3HT-based diblock copolymer/SWCNT nanocomposites was examined by microscopic and spectroscopic characterizations, exhibiting a charge transfer behavior between P3HT and SWCNT, and growth of the P3HT crystalline phase along the SWCNT surface with a form of the conducting path. The acquired SWCNT nanocomposites exhibited good solubility and dispersion in various organic solvents including toluene, chlorobenzene, THF, chloroform, and DMF, which are good solvents for the PSty or/and PNSS neutral second block. The concept for the neutralized second block by protecting groups can prevent the poisoning ITO substrate by water contamination as shown in the conventional aqueous PEDOT-PSS solution. Notably, the PNSS constituent in the nanocomposite was merely acidified to give in-situ sulfonic acid groups in PSty by simple thermolysis process at 160 °C for 30 min after a solution process for fabrication of a thin film. The thermolysis step provided efficient doping of P3HT by PSS, in which the thiophene groups worked as Brønsted base are protonated by taking protons from sulfonic acid groups and then lead to a form of ionic bonds between cationic thiophene and anionic sulfonate groups. In addition, the formed ionic bonds in the nanocomposites led to an insoluble thin film, which has a good advantage for the further solvent process without substantial damages. The beneficial features of the conducting path along SWCNT and the efficient doping of P3HT by PSS in the acquired nanocomposites led to ca. 5-fold higher electrical conductivity (3.16 S cm−1) and similar work function (5.1 eV) in comparison to water contained commercial PEDOT:PSS (0.6 S cm−1 and 5.0 eV, respectively). As such, the rationally designed potentially self-dopable SWCNT nanocomposites can be one of the promising alternatives beyond the commercial PEDOT: PSS HTL material.

Design, synthesis and biological evaluation of 1,4-dihydroxyanthraquinone derivatives as anticancer agents

The novel hydroxyanthraquinone derivatives containing nitrogen-mustard and thiophene group were designed to covalently bind to topoisomerase II, and their structures were confirmed by nuclear magnetic resonance and high resolution mass spectrometer technologies in this article. The in vitro cytotoxicity against different cancer cell lines and one normal liver cell line (L02) was evaluated by MTT assay. Compound A1 was the most potent anti-proliferative agent against the human liver cancer HepG-2 cells (IC50 = 12.5 μM), and there is no obvious growth inhibitory effect on normal liver tissue L02 cells. The good cytotoxicity and selectivity of compound A1 suggest that it could be a promising lead for further optimization. The mechanisms of action about compound A1 and A4 were further investigated through analysis of cell apoptosis. Confocal microscopy tracks the location of compound A1 in the cell, which could enter the cytoplasm and nucleus, and induce severe deformation of the nucleus. The docking study demonstrated that A1 could interact with the catalytic active site in topoisomerase II.

Preparation and microwave absorption properties of Nanomesh Poly (3,4-ethylenedioxythiophene) covalently functionalized graphene oxide

In this work, we report a simple and effective method to prepare conducting poly (3,4-ethylenedioxythiophene)/thiophene-grafted graphene oxide (Th-GO-PEDOT) composite with enhanced microwave absorption properties. The first step, the carboxyl group of graphene oxide was converted into an acyl chloride intermediate by treating with thionyl chloride and then reacted with thiophene to give the thiophene group. The second step, the target product of Th-GO-PEDOT was successfully obtained by in-situ polymerization of 3,4-ethylenedioxythiophene on the surface of thiophene-grafted graphene nanosheets (Th-GO). The resulting samples were fully characterized by Raman spectroscopy, FT-IR, X-ray and Vector network analyzer. The as-prepared Th-GO-PEDOT composites exhibited superior electromagnetic microwave absorption performance and showed the minimum reflection loss (RL) of − 47.5 dB (99.9% microwave absorption) at 15.5 GHz frequency and effective frequency (RL ≤ − 10 dB) of 4.9 GHz only 1.5 mm matching thickness. This study found that the strong covalent bond interaction between PEDOT and graphene is the crucial factor for the enhanced EM absorption performance, which provided a method for designing and manufacturing the microwave absorption materials further to meet the requirements of the ideal absorber.

Designing Donor-Acceptor thienopyrazine derivatives for more efficient organic photovoltaic solar cell: A DFT study

The present work focuses on the design and development of new thienopyrazine-derivatives in alternate Donor-Acceptor (D-A) structure for solar cells applications. Eight molecules based on thienopyrazine combined with the electron-rich thiophene or bithiophene units have been investigated using the DFT and TDDFT methods with B3LYP functional implemented with 6-31G(d,p) basis set. The focus was on the effect of substitution and doping on the structural, optoelectronic, photovoltaic and transporting properties. The result shows that the substitution by bithiophene groups decreases energy gap (Eg), produces a high bathochromic shift and increases oscillator strength of the lowest-lying transition compared to the substitution with thiophene groups. The doping of studied molecules makes them more planar and improves their electronic properties. Other characteristics, such as the ionization potential (IP), electronic affinity (EA), reorganization energies (λ+ and λ−), voltage in open circuit (Voc), and charge transfer are discussed. All of the molecules show moderate values of voltage in open circuit and efficient charge transfer. In the light of these results, we suggest promising models of systems for applications in optoelectronic. OPVC solar cell based on the most appropriate designed molecule (low band gap and high VOC) in bulk heterojunction composite with [6,6] -phenyl-C61-butyric acid methyl ester (PCBM) as an acceptor has been modeled. A model energy band diagram is described for OPVC to simulate the energy transfer between active layers. These materials are potentially interesting for the realization of optoelectronic devices and can be qualified as future materials for renewable energy.

Promoter Effects of Functional Groups of Hydroxide-Conductive Membranes on Advanced CO2 Electroreduction to Formate.

The electrochemical reduction of CO2 at ambient conditions provides a latent solution of turning waste greenhouse gases into commodity chemicals or fuels; however, a satisfactory ion-conducting membrane for maximizing the performance of a CO2 electrolyzer has not been developed. Here, we report the synthesis of a sequence of hydroxide-conductive polymer membranes, which are based on polymer composites of poly(vinyl alcohol)/Guar hydroxypropyltrimonium chloride, for use in CO2 electrolysis. The effect of different membrane functional groups, including thiophene, hydroxybenzyl, and dimethyloctanal, on the efficiency and selectivity of CO2 electroreduction to formate is thoroughly evaluated. The membrane incorporating thiophene groups exhibits the highest Faradaic efficiency of 71.5% at an applied potential of -1.64 V versus saturated calomel electrode (SCE) for formate. In comparison, membranes containing hydroxybenzyl and dimethyloctanal groups produced lower efficiencies of 67.6 and 68.6%, respectively, whereas the commercial Nafion 212 membrane was only 57.6% efficient. The improved efficiency and selectivity of membranes containing thiophene groups are attributed to a significantly increased hydroxide conductivity (0.105 S cm-1), excellent physicochemical properties, and the simultaneous attenuation of formate product crossover.

Anesthetic efficacy of single buccal infiltration of 4% articaine and 2% lignocaine in extraction of maxillary 1st molar

Background:The extraction of tooth being the most common procedure in oral surgery should be pain free with limited dosage and limited needlepricks. Articaine being unique among amide local anesthetics contains a thiophene group, which increases its liposolubility, and an ester group which helps biotransformation in plasma. Because of the high diffusion properties, it can be used as a single buccal infiltration to extract a maxillary tooth.Aim and Objective:Objective of the study was to compare the efficacy of single buccal infiltration of 4% articaine with that of 2% lignocaine for maxillary first molar extraction.Methodology:A triple blind randomized controlled study was carried on 100 patients of age group 18-60 years who required maxillary first molar extraction, visiting the Department of Oral and Maxillofacial surgery. They were included in the study after obtaining informed consent. Buccal infiltration of 1.8 ml of anesthetic solution was given randomly to 100 patients with appropriate blinding of the cartridges. Objective signs were checked. If any additional injection was given, it was noted as type and number of rescue injection given. Postoperatively VAS score and surgeon's quality of anesthesia was noted. Duration of anesthesia was measured every 5 minutes for 50 minutes from infiltration.Results:Out of 50 patients in group A (Articaine), in 44 patients extraction was done without the need of additional injection whereas in group B(Lignocaine), 29 patients require additional infiltration on the palatal side. The VAS score values for group A were also significantly less in comparison with group B. The mean duration of anesthesia for Group A being (71.70 ± 17.82 min) in 44 patients who only received buccal infiltration.Interpretation and Conclusion:The efficacy of single buccal injection of articaine is comparable to buccal and palatal injection of lignocaine.

Recyclable mechanoluminescent luminogen: different polymorphs, different self-assembly effects of the thiophene moiety and recovered molecular packing via simple thermal-treatment

We report a purely organic recyclable mechanoluminescent luminogen (tPE-5-MeTh) with a thiophene group as the self-assembly unit. The recoverability could be achieved through simple thermal-treatment.

Dendritic copolymer electrode for second harmonic alternating current voltammetric signalling of pyrene in oil-polluted wastewater

A sensitive dendritic star copolymer-based sensor for pyrene (PY), was developed by in situ electrosynthesis of generation 3 poly(propylene thiophenoimine)-co-poly(3-hexylthiophene) (G3PPT-co-P3HT) on a gold disk electrode (Au). The electrochemical reactivity and the signal transduction properties of the Au|G3PPT-co-P3HT co-polymer electrode were studied by second harmonic alternating current voltammetry (SHACV) and alternating current voltammetry (ACV), respectively. SHACV analysis confirmed the occurrence of Faradaic electrode process (with a standard rate constant, k0 value of 3.36 cm s−1), possibly originating from the surface-confined thiophene groups of the co-polymer electrode. The ACV responses of the Au|G3PPT-co-P3HT electrode to pyrene gave a linear range (LR) of 2.73–26.86 nM and a limit of detection (LOD) of 1.34 nM PY. The low LOD value suggests that the PY sensor has promise for monitoring compliance to the World Health Organization (WHO) approved limit for polyaromatic hydrocarbons (PAHs) in wastewater, which is 3.93 nM. The sensor was used to determine PY levels in oil-polluted wastewater samples, which were found to contain 4.93–23.49 nM PY, depending on how far into the sea the samples were collected. The high recovery rate obtained for the oil-polluted seawater samples, indicate that ACV signalling protocol makes the Au|G3PPT-co-P3HT electrode very suitable for application in samples that have complex matrices.

Donor functionalized quinoline based organic sensitizers for dye sensitized solar cell (DSSC) applications: DFT and TD-DFT investigations.

The influence of different donor groups in quinoline based novel sensitizers for dye sensitized solar cell (DSSC) applications is analyzed by using density functional theory (DFT) and time dependent density functional theory (TD-DFT). Quinoline and donor functionalized quinoline based novel organic sensitizers have been designed with different π-spacers for DSSC applications. The ground state molecular structure of novel organic sensitizers is fully optimized by DFT calculation in both gas and chloroform phases. Electronic absorption characteristics are predicted by the TD-DFT calculation in both gas and chloroform phases. The polarizable continuum model is used for solvent phase optimization. The net electron transfer from the donor to acceptor is calculated from natural bond orbital (NBO) analysis. The injection energy and dye regeneration energy values are also calculated. Different donor groups are substituted in quinoline, and these substituted quinoline donors are used as the donor group. Cyanovinyl and thiophene groups act as π-spacers and cyanoacrylic acid acts as an acceptor. DFT and TD-DFT studies of the quinoline and donor functionalized quinoline sensitizers show that the coumarin based and N-hexyltetrahydroquinoline donors are more efficient for DSSC application.