Thiophene Groups Research Articles

Introducing thiophene and benzothiadiazole groups in triphenylamine-based organic dyes with rigidly fused π-bridge to design high-efficiency solar cells: A theoretical investigation

The influence of different types of π-bridges in triphenylamine-based organic sensitizers on their photophysical and photovoltaic properties is investigated by using sophisticated first-principles calculations and reliable theoretical models. Two well-designed strategies, namely the cyclization between separate benzothiadiazole and bithiophene as well as the insertion of electron-rich/deficient groups between the rigidly fused π-bridge and anchor moieties are proposed. It is found that the calculated photophysical and photovoltaic parameters of the dye with an unfused π-bridge reproduce very well the available experimental data, ensuring the rationality of present theoretical methods and models. The designed dye featuring a rigidly fused π-bridge shows a remarkable decrease of power conversion efficiency (PCE), with respect to the dye with an unfused π-spacer (6.36% vs. 11.18%), which implies that simply cyclizing separate aromatic heterocyclic groups is unfavorable for improving the photoelectrical performance. However, the PCE can be increased to 14.20% when an electron-rich thiophene group is introduced between the fused π-bridge and the anchor units. More importantly, replacing the thiophene moiety with an electron-deficient benzothiadiazole group can further improve the photovoltaic performance, and consequently a PCE as high as 23.81% is achieved, which is a significant theoretical improvement for triphenylamine-based organic dyes. To sum up, this study theoretically elucidates the effect of unfused and fused π-bridges as well as the introduction of electron-rich/deficient groups in organic dyes on their photophysical and photoelectric properties and provides a useful guidance for further designing highly-efficient dye sensitizers by molecular engineering.

Unsymmetrical zinc phthalocyanines containing thiophene and amine groups as donor for bulk heterojunction solar cells.

Photovoltaic technology is an alternative resource for renewable and sustainable energy and low costs organic photovoltaic devices such as bulk-heterojunction (BHJ) solar cells, which are selective candidates for the effective conversion of solar energy into electricity. Asymmetric phthalocyanines containing electron acceptor and donor groups create high photovoltaic conversion efficiency in dye sensitized solar cells. In this study, a new unsymmetrical zinc phthalocyanine was designed and synthesized including thiophene and amine groups at peripherally positions for BHJ solar cell. The structure of the targeted compound (4) was characterized comprehensively by FT-IR, UV–Vis, 1H-NMR, and MALDI-TOF MS spectroscopies. The potential of this compound in bulk heterojunction (BHJ) photovoltaic devices as donor was also researched as function of blend ratio (blend ratio was varied from 0.5 to 4). For this purpose, a series of BHJ devices with the structure of fluorine doped indium tin oxide (FTO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/ ZnPc:[6,6]- phenyl-C61- butyric acid methyl ester (PCBM) blend/Al with identical thickness of ZnPc:PCBM layer were fabricated and characterized. Photo current measurements in 4 revealed that the observed photo current maximum is consistent with UV-vis spectra of the compound of 4. Preliminary studies showed that the blend ratio has a critical effect on the BHJ device performance parameters. Photovoltaic conversion efficiency of 6.14% was achieved with 4 based BHJ device.

A Cathodic Electrochromic Material Based on Thick Perylene Bisimide Film with High Optical Contrast and High Stability

A Cathodic Electrochromic Material Based on Thick Perylene Bisimide Film with High Optical Contrast and High Stability

Thiophene-based MOFs for iodine capture: Effect of pore structures and interaction mechanism

The effective capture of radioiodine is vital to the development of the nuclear industry and environmental protection. Metal-organic frameworks (MOFs) are promising adsorbents for iodine vapor due to the versatile metal nodes and linkers, as well as tunable pore structures. Here, five thiophene-based metal–organic frameworks with different pore geometries were investigated for their iodine adsorption properties, and the relationship between the pore structures and iodine adsorption capacities is examined. DUT-68 adsorbs a large amount of iodine (1081 mg/g), which is 28% higher than that of the homologous DUT-67 (843 mg/g), because its large cage could provide more space for the packing of molecular iodine in the middle of the pore. The MIL-53-TDC(In) with 1D straight-through pore channels only has an iodine capacity of 660 mg/g, due to its small pore volume and little confinement effect. Meanwhile, the In-DTC and Ho-DTC, with smaller pore sizes than the kinetic diameter of iodine molecules, exhibit almost no iodine adsorption properties. Raman, fluorescence, XPS spectra and DFT calculation confirm the strong charge transfer effect from thiophene linkers to trapped iodine. DFT calculation also provides quantitative adsorption energy of −44.5 kJ/mol between one iodine molecule and one thiophene group linked with Zr nodes, higher than that of thiophene groups linked with In nodes. This work may motivate the topology-directed design of MOFs for iodine capture with optimized pore structures, metal nodes and linkers to enhance the adsorption performance.

Design and synthesis of Phenylaminothiophene donor-based chromophore with enhanced electro-optic activity

Three novel chromophores B-D have been synthesized based on thiophene derivatived donors, including 5-(methyl(phenyl)amino)thiophene 5-(bis(4-methoxyphenyl)amino)thiophene 5-((4-methoxyphenyl)(methyl)amino)thiophene groups respectively, with the same isophorone-derived bridge and tricyanovinyldihydrofuran (TCF) acceptors. A new strategy was proposed to improve the electron donating ability of the chromophore, thienyl groups were explored as a replacement for the phenyl unit in the donor part of the chromophore. Density functional theory calculations suggested that the first hyperpolarizability of (arylamino) thiophene donor-containing chromophore B-D is about 20% higher than that of 4-(dialkylamino) phenyl counterpart chromophore A. At least 50% enhancement in bulk nonlinearity (r33) is realized as the donor subunits were changed from alkylaniline to (arylamino) thiophene donors. Polymeric thin films doped with 25 wt% chromophore B-D have been poled to afford large r33 values of 131, 143 and 138 p.m./V at 1.31 μm, respectively, which is much higher than the EO activity of chromophore A (88 pm/V).

Role of π conjugation in n-hexylphenothiazine dyes for solar cell-a density functional theory approach.

The N-hexylphenothiazine-based organic sensitizers are designed for Dye Sensitized Solar Cell (DSSC). The different π spacer (thiophene and cyanovinyl) groups were substituted in third and seventh position N-hexylphenothiazine. From the structural modifications, the π spacer effect was analyzed. The optoelectronic properties of the dyes were tuned by structural modifications. The optimized geometry, highest occupied molecular orbital and lowest unoccupied molecular orbital energy level, and absorption spectra were calculated. The natural bond orbital analysis gives the net electron transfer from the donor to acceptor. The electrochemical properties and light-harvesting efficiency of the designed dye sensitizers were calculated. The π spacer increase resulted in the redshift of the absorption peak. Based on the density functional theory and time dependant density functional theory calculations, the designed dye molecules are evaluated for DSSC application.

Covalent 2D Patterning, Local Electronic Structure and Polarization Switching of Graphene at the Nanometer Level.

A very facile and efficient protocol for the covalent patterning and properties tuning of graphene is reported. Highly reactive fluorine radicals were added to confined regions of graphene directed by laser writing on graphene coated with 1‐fluoro‐3,3‐dimethylbenziodoxole. This process allows for the realization of exquisite patterns on graphene with resolutions down to 200 nm. The degree of functionalization, ranging from the unfunctionalized graphene to extremely high functionalized graphene, can be precisely tuned by controlling the laser irradiation time. Subsequent substitution of the initially patterned fluorine atoms afforded an unprecedented graphene nanostructure bearing thiophene groups. This substitution led to a complete switch of both the electronic structure and the polarization within the patterned graphene regions. This approach paves the way towards the precise modulation of the structure and properties of nanostructured graphene.

Effect of Functionalization of Reduced Graphene Oxide Coatings with Nitrogen and Sulfur Groups on Their Anti-Corrosion Properties.

Electrophoretic production of anticorrosion carbonaceous coatings on copper could be successfully performed by anodic oxidation of negatively charged graphene platelets suspended in an aqueous solution. The various platelets were synthesized by Hummer’s method followed by a hydrothermal reduction in the presence of NH4SCN which was expected to substitute some parts of graphene structure with nitrogen and sulfur groups. X-ray photoelectron spectroscopy analysis confirmed that the graphene precursors, as well as the coatings, contained typical nitrogen groups, such as pyridinic and pyrrolic, and sulfur groups, such as thiol, thiophene, or C-SO2. However, due to oxidation during deposition, the qualitative and quantitative composition of the graphene coatings changed relative to the composition of the precursors. In particular, the concentration of nitrogen and sulfur dropped and some thiophene groups were oxidized to C-SO2. Studies showed the functionalized coatings had a uniform, defect-free, hydrophobic, more adhesive surface than nonmodified films. The corrosion measurements demonstrated that these coatings had better protective properties than the ones without these heteroatoms. This behavior can be assigned to the catalytic activity of nitrogen towards oxidation of C-SO2 groups to C-SO3H with oxygen.

Su Sertliğinin Filtre Kahvenin Uçucu Bileşenlerine ve Lezzetine Etkisi

Su kahve hazırlamada kahve çeşidinden sonra ikinci önemli bileşen olup kahve kalitesini etkilemektedir. Bu çalışmada filtre kahve hazırlamada kullanılan dört farklı sertliğe sahip suyun (şişelenmiş, arıtma, orta sert ve sert su) filtre kahvenin uçucu bileşenlerine ve lezzetine etkisinin araştırılması amaçlanmıştır. En fazla sayıda uçucu bileşen orta sertlikteki su kullanılarak hazırlanan filtre kahvede (12 furan, 7 pirazin, 3 pirol, 2 aldehit, 1 furanon,1 keton, 1 piridin ve 1 tiyofen grubundan olmak üzere toplam 28 uçucu bileşen) belirlenmiştir. Filtre kahve hazırlamada kullanılan suyun sertliğinin 2-metilfuran, 2-metilbutanal, 5-metil-3-hegzanon, 1-metil-1H-pirol, 2-vinil-5-metilfuran, 2-(metoksimetil) furan, dihidro-2-metil- 3(2H)-furanon, 2-etil-3-metil-pirazin, 3-etil-2,5-dimetil-pirazin, 2-furankarboksaldehit, benzaldehit, 2,2'-bifuran ve 2,2'-metilenbisfuran uçucu bileşenlerinin alan yüzdesini etkilediği tespit edilmiştir. Koku karakterleri (kavrulmuş kahve (2,27), kavrulmuş fındık (2,35), badem (0,96), çiğ sebze (2,69), toprak (0,96)) sert suyla hazırlanan filtre kahvelerde düşük yoğunlukta algılanmıştır. Sert suyla hazırlanan filtre kahvede tat karakterlerinden acı (3,63) en fazla algılanırken, en az algılanan karakterler fındık (0,40), baharat (0,63), limon kabuğu (0,58), tatlı (1,04), ekşi (1,52) tat olmuştur. Orta sert suyla hazırlanan filtre kahvede ise fındık (1.63), baharat (1.96), limon kabuğu (3.21), tatlı (2.23) tat karakterleri yoğun algılanmıştır. Ekşilik yumuşak suyla hazırlanan örneklerde en yoğun algılanırken (3,55), orta sert suyla hazırlanan kahvelerde ekşiliğin yoğunluğu azalmış (2,55), en düşük ise sert suyla hazırlanan örneklerde (1,52) algılanmıştır. Çalışma sonucunda su sertliğinin filtre kahvenin lezzetini etkilediği belirlenmiş olup, daha fazla uçucu bileşen içeren filtre kahve elde edilmesi için filtre kahve hazırlanmada orta sertlikte suyun kullanılması önerilmektedir.

Chimeric Drug Design with a Noncharged Carrier for Mitochondrial Delivery.

Recently, it was proposed that the thiophene ring is capable of promoting mitochondrial accumulation when linked to fluorescent markers. As a noncharged group, thiophene presents several advantages from a synthetic point of view, making it easier to incorporate such a side moiety into different molecules. Herein, we confirm the general applicability of the thiophene group as a mitochondrial carrier for drugs and fluorescent markers based on a new concept of nonprotonable, noncharged transporter. We implemented this concept in a medicinal chemistry application by developing an antitumor, metabolic chimeric drug based on the pyruvate dehydrogenase kinase (PDHK) inhibitor dichloroacetate (DCA). The promising features of the thiophene moiety as a noncharged carrier for targeting mitochondria may represent a starting point for the design of new metabolism-targeting drugs.

Design, Synthesis, Molecular Docking, and Tumor Resistance Reversal Activity Evaluation of Matrine Derivative with Thiophene Structure.

Nasopharyngeal carcinoma (NPC) frequently occurs in Southern China. The main treatments of NPC are chemotherapy and radiotherapy. However, chemo-resistance arises as a big obstacle in treating NPC. Therefore, there is a great need to develop new compounds that could reverse tumor drug resistance. In this study, eight matrine derivatives containing thiophene group were designed and synthesized. Structures of these 8 compounds were characterized by 1H-NMR, 13C-NMR, and high-resolution mass spectrometer (HRMS). The cytotoxicity and preliminary synergistic effects of these 8 compounds were detected against nasopharyngeal carcinoma (NPC) cells and cisplatin-resistant NPC cells (CNE2/CDDP), respectively. Furthermore, the in vivo and in vitro tumor resistance reversal effects of compound 3f were evaluated. Moreover, docking studies were performed in Bclw (2Y6W). The results displayed that compound 3f showed synergistic inhibitory effects with cisplatin against CNE2/CDDP cells proliferation via apoptosis induction. Docking results revealed that compound 3f may exert its effects via inhibiting anti-apoptosis protein Bcl-w.

Influence of chemical structure on thermal, optical and electrochemical properties of conjugated azomethines

A correlation between a chemical structure of π-conjugated azomethines and their physicochemical properties has been studied, towards their optoelectronic applications. Eight various homo-aryl moieties have been coupled with either phenylene or thiophene groups, via imine bond, resulting in 15 (9 novel) azomethines. Differential scanning calorimetry (DSC), thermogravimetric analysis (TG), UV-Vis absorption and photoluminescence spectroscopy, and cyclic voltammetry techniques have been used to investigate their thermal, optical and electrochemical properties. Moreover, these results have been supported by the density functional theory (DFT) calculations. Introduction of thiophene rings, into the structure of studied azomethines, proved to increase resistance towards hydrolysis, their thermal stability and reduction potential, together with an enhancement of their π-delocalization. Simultaneously, the presence of thiophene rings in azomethine structures has decreased their emissive properties, compared to their completely homo-aryl analogues. The highest thermal stability and the most enhanced conjugation has been observed for azomethines consisting of such central units moieties as fluorene, naphtalene and biphenylene. Surprisingly, the presence of conjugation breaking ether or methylene bridge provides interesting photoluminescence properties, when coupled with thiophene. Finally, the substitution with side methyl groups proved to induce a reduction of oxidation potential and an increase of melting temperatures. Thiophene, fluorene, naphtalene and biphenylene groups, due to enhancement of thermal stability and extension of absorption range, appear to be good building units for novel materials for photovoltaic structures, while the most promising properties in the context of application in emissive devices have been observed for phenylene-coupled compounds with such groups as phenylene or biphenylene.

Exploring the Effect of the Number of Characteristic Groups in Melaminebased Polymers on the Photocatalytic Performance

: Three polymers containing different numbers of thiophene groups were constructed. Degradation experiments on the aqueous solutions of tetracycline and norfloxacin revealed that the polymer with three thiophene groups in the monomer indicated the best degradation efficiency of 73.7% for tetracycline and 56.9% for norfloxacin. Moreover, this polymer had a relatively stronger ability to separate and transport photocharging carriers under visible light. Therefore, the photocatalytic performance of conjugated polymers could be regulated by changing the number of characteristic groups. Background: Antibiotic residues in the environment are considered as one of the most serious sources of environmental pollution. Although catalyst photodegradation is regarded as the most promising strategy to solve environmental pollution-related problems, it still requires new and advanced photocatalysts. Objective: To design new organic conjugated material structures. Material and Methods: Three polymers (ThME-1, ThME-2, and ThME-3) were prepared by the condensation of melamine with 2, 5-thiophenedicarboxaldehyde, thieno[3, 2-b]thiophene-2, 5-dicarbaldehyde, and dithieno[3, 2-b:2’, 3’-d]thiophene-2, 6-dicarbaldehyde. The photocatalytic performance of these polymers was investigated by testing their diffused light absorption capacity, photocurrent response, AC impedance, specific surface area, fluorescence, and thermal stability. Results: ThME-3, containing three thiophene groups in the monomer, manifested the best degradation efficiency of 73.7% for tetracycline and 56.9% for norfloxacin. Conclusion: The photocatalytic performance of conjugated polymers could be regulated by changing the number of characteristic groups.

Simple anthracene derivatives: different mechanoluminescence properties tailored only by a thiophene group

Here, anthracene was selected as the fluorescent core, then boronic ester and the self-assembling thiophene group were introduced to the “9” and “10” sites of anthracene, respectively.

Chalcogen bonding mediates the formation of supramolecular helices of azapeptides in crystals.

To explore whether chalcogen bonding was able to drive the formation of supramolecular helices, alanine-based azapeptides containing a β-turn structure, with a thiophene group, respectively, incorporated in the N- or C-terminus, were employed as helical building blocks. While the former derivative formed a supramolecular M-helix via intermolecular SS chalcogen bonding in crystals, the latter formed P-helix via intermolecular SO chalcogen bonding.

Electrochromic properties of pyrene conductive polymers modified by chemical polymerization.

Pyrene is composed of four benzene rings and has a unique planar melting ring structure. Pyrene is the smallest condensed polycyclic aromatic hydrocarbon, and its unique structural properties have been extensively studied. Pyrene has excellent properties such as thermal stability, high fluorescence quantum efficiency and high carrier mobility. This paper mainly used thiophene, EDOT and triphenylamine groups to enhance the pyrene based π-conjugated system and control the molecular accumulation of organic semiconductors, and improve their charge transport performances. Five kinds of polymer were synthesized and correspondingly characterized. The five kinds of pyrene conductive polymer had outstanding properties in terms of solubility, fluorescence intensity and thermal stability, good film-forming properties, stable electrochromic properties and high coloring efficiency. The coloration efficiency (CE) of PPYTP was as high as 277 cm2 C−1, and the switching response time was short. The coloring time of PPYEDOT was 1.3 s and the bleaching time was 3.2 s. The lower impedance will also provide the possibility of such polymers being incorporated into electrochromic devices in the future. In short, the synthesized new pyrene conductive polymers will have wide application prospects in the field of electrochromic materials.

Polymer defect engineering – conductive 2D organic platelets from precise thiophene-doped polyethylene

Synthesis and crystallization of polyethylene with precisely positioned thiophene groups were used to produce polymer crystals with a conductive surface.

Study on the influence of the introduction of the thiophene group on the photocatalytic performance of polymer

Two novel conjugated organic polymers BTTh-1 and BTTh-2 were designed and synthesized. They were prepared by the reaction of two aldehyde units with melamine. Both aldehyde units were based on benzothiadiazole. The difference between the final aldehyde units was the introduction of thiophene groups in the BTTh-2 aldehyde monomer units. The difference between the two materials in the photocatalytic degradation of tetracycline was discussed in the context of the thiophene unit. The degradation efficiency of tetracycline by BTTh-2 (90.9%) was much higher than that of BTTh-1 (40.7%). The characterization results showed that BTTh-2 has a strong charge separation ability and fast transmission rate. After light excitation, the recombination ability of photogenerated holes and electrons becomes weak, and it has better utilization ability for visible light; the bandgap width is narrower.

Direct current powered humidity sensor based on a polymer composite with humidity sensitive electronic conduction

Solid-state humidity sensors are generally AC powered as they sense the fluctuations in the dielectric polarization and/or ionic conductance of the water layer formed by Kelvin condensation on the effective surface of their hydrophilic sensing elements. DC-powered, printable, and bendable hygrometers, however, are demanded for battery-driven wearable electronics. Here, we demonstrate that the electronic (as opposed to ionic) conduction in the polymer composite poly(3,4-ethylenedioxythiophene–poly(styrenesulfonate) (PEDOT:PSS) thin films constantly decreases with increasing relative humidity (RH) in the surrounding atmosphere and use this property for the fabrication of a DC-powered solid state hygrometer. PEDOT, the conductive component of this composite, is hydrophobic, and the hydrogen bonding of the airborne H2O to the surface available sulfonic acid groups of the non-conductive component, PSS, is verified as the main cause of sensitivity. This hydrogen bonding deters the doping action involving H+ transfer from the sulfonic acid groups to the thiophene groups on the PEDOT chain and decreases the bulk conductivity of the sensing element. As predicted by this model, the electrical resistance measurements carried out by applying DC and AC electric fields lead to different RH dependences; the former demonstrates the positive RH dependence in the full RH range, while the latter results in strongly nonlinear RH sensitivity crossing zero around RH 60%. Our model assists better understanding of the charge conduction mechanisms in PEDOT:PSS. The described sensing mechanism is anticipated to initiate research on many two-component organic composites for the fabrication of varieties of gas and humidity sensors.

Phenylthioether thiophene-based oxime esters as novel photoinitiators for free radical photopolymerization under LED irradiation wavelength exposure

Four new photoinitiators (PIs) containing phenylthioether-substituted thiophene groups as chromophores and oxime ester groups as initiating groups were designed and synthesized. These compounds exhibit excellent absorption under exposure to light-emitting diode (LED) irradiation wavelength (i.e., 365–425 nm). Moreover, they have a higher radical generation efficiency than the commercial PI O-benzoyl-α-oxooxime (i.e., OXE 01). The mechanism by which these oxime esters generate radicals was investigated via steady-state photolysis, high performance liquid chromatography, and online 1H NMR. These PIs can efficiently initiate the polymerization of acrylate monomer. Acetyl oxime esters show higher conversions than OXE 01 under LED irradiation at 365–425 nm. The methyl substituent on the benzene ring, the volume effect of the large alkyl group, and the acetyl substitution on the oxime ester all contribute to high photoinitiation efficiency. Owing to their excellent absorption and efficient photoinitiation properties, these optimized PIs have great potential in photocuring applications.