Benzothiadiazole Derivative Research Articles

Selective Construction and Structural Transformation of Homogeneous Linear Metalla[4]catenane and Metalla[2]catenane Assemblies.

Although the synthesis of mechanically interlocked molecules has been extensively researched, selectively constructing homogeneous linear [4]catenanes remains a formidable challenge. Here, we selectively constructed a homogeneous linear metalla[4]catenane in a one-step process through the coordination-driven self-assembly of a bidentate benzothiadiazole derivative ligand and a binuclear half-sandwich rhodium precursor. The formation of metalla[4]catenanes was facilitated by cooperative interactions between strong sandwich-type π-π stacking and non-classical hydrogen bonds between the components. Moreover, by modulating the aromatic substituents on the binuclear precursor, two homogeneous metalla[2]catenanes were obtained. The molecular structures of these metallacatenanes were unambiguously characterized by single-crystal X-ray diffraction analysis. Additionally, reversible structural transformation between metal-catenanes and the corresponding metallarectangles could be achieved by altering their concentration, as confirmed by mass spectrometry and NMR spectroscopy studies.

Selective Construction and Structural Transformation of Homogeneous Linear Metalla[4]catenane and Metalla[2]catenane Assemblies

AbstractAlthough the synthesis of mechanically interlocked molecules has been extensively researched, selectively constructing homogeneous linear [4]catenanes remains a formidable challenge. Here, we selectively constructed a homogeneous linear metalla[4]catenane in a one‐step process through the coordination‐driven self‐assembly of a bidentate benzothiadiazole derivative ligand and a binuclear half‐sandwich rhodium precursor. The formation of metalla[4]catenanes was facilitated by cooperative interactions between strong sandwich‐type π‐π stacking and non‐classical hydrogen bonds between the components. Moreover, by modulating the aromatic substituents on the binuclear precursor, two homogeneous metalla[2]catenanes were obtained. The molecular structures of these metallacatenanes were unambiguously characterized by single‐crystal X‐ray diffraction analysis. Additionally, reversible structural transformation between metal‐catenanes and the corresponding metallarectangles could be achieved by altering their concentration, as confirmed by mass spectrometry and NMR spectroscopy studies.

Ultra-Photostable Random Lasing Coming from the Benzothiadiazole Derivative Dye-Doped Organic System

Ultra-Photostable Random Lasing Coming from the Benzothiadiazole Derivative Dye-Doped Organic System

A solvent- and pH-stable NiII-based metal-organic framework with benzothiadiazole derivative for proton conduction

A one-dimensional metal–organic framework (MOF) with the formula of {[Ni(BIBT)(pydc)(H2O)2]·H2O}n (JXUST-26, BIBT = 4,7-bis(1H-imidazole-1-yl)-2,1,3-benzothiadiazole, H2pydc = 3,5-pyridinedicarboxylic acid) has been successfully synthesized under solvothermal condition, which crystallizes in the monoclinic C2/c space group. It is noteworthy that JXUST-26 exhibits good solvents and pH stabilities as well as relatively good thermal stability. The proton conductivity increases with increasing temperature, and reaches 1.65 × 10−8 S·cm−1 at 30 °C and 3.24 × 10−7 S·cm−1 at 80 °C under 98% relative humidity, respectively. In the low temperature range of 303–353 K, the activating energy (Ea) is 0.51 eV, which belongs to the Vehicle mechanism.

Rational Design of a Multifunctional Benzothiadiazole Derivative in Organic Photonics and Electronics.

In order to achieve a multifunctional compound with potential application in organic photonics and electronics, a multidonor benzothiadiazole derivative was rationally designed and synthesized employing microwave irradiation as energy source, increasing the process efficiency about yields and reaction times in comparison with conventional conditions. This powerful compound displayed solvatochromism and showed efficient behavior as red optical waveguide with low OLC around 10-2 dB μm-1 and with the capacity of light transmission in two directions. In addition, the proposed derivative acted as efficient p-type semiconductor in organic field-effect transistors (OFETs) with hole mobilities up 10-1 cm2 V-1 s-1 . This corroborates its multifunctional character, thus making it a potential candidate to be applied in hybrid organic field-effect optical waveguides (OFEWs).

F···Br and F···S Heterohalogen-Bond-Directed 2D Self-Assemblies of a Benzothiadiazole Derivative.

Halogen bonding (XB) is of great importance in fabricating a two-dimensional (2D) self-assembly for its adaptive directionality. However, the XBs involving fluorine (F) have barely been studied due to the absence of an σ-hole on F. Here, 2D self-assemblies of a F-substituted 4,7-bis(5-bromo-4-dodecylthiophen-2-yl)-5,6-difluorobenzo[c][1,2,5]thiadiazole (BTZ-BrF) molecule on graphite were investigated using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. STM experiments revealed that the 2D patterns of BTZ-BrF had a clear solvent and concentration dependence, showing a frame-like pattern in aliphatic acid and aliphatic hydrocarbon solvents at high concentrations. At lower concentrations, a bamboo-like and a wave-like pattern were observed in aliphatic acid, whereas small frame-like and large ladder-like domains at high solution concentrations in aliphatic hydrocarbon were observed. As the concentration further decreased, two linear patterns were observed. DFT calculations suggested that the hetero-XBs of F···Br, F···S, Br···S, and Br···N, the homo-XBs of type-II Br···Br, and the S···S interactions synergistically directed and stabilized the polymorphic 2D architectures. This understanding of intermolecular XBs during the molecular assembly at the molecular level may shed light on the ongoing efforts of regulating nanostructures of multifunctional organics.

A New Benzothiadiazole Derivative with Systemic Acquired Resistance Activity in the Protection of Zucchini (Cucurbita pepo convar. giromontiina) against Viral and Fungal Pathogens

The ability of plant resistance inducers to provide protection against viral diseases is one of their main advantages over conventional pesticides. In the case of viral diseases that cannot be controlled directly with pesticides, insecticides are used to control the vectors of viruses. However, the effectiveness of such treatments is strictly dependent on the time of application. The plant response to the application of systemic acquired resistance (SAR) inducers, as a result of the stimulating action of these substances, does not depend on the time of application as it triggers the plant's natural defence mechanism. The best-recognised substance showing SAR inducer activity is acibenzolar-S-methyl ester (ASM, BTH). As its activity against different plant pathogens of crops has been well documented, the current research is concentrated on the search for novel substances of the type. The tested substance, N-methoxy-N-methylbenzo(1,2,3)thiadiazole-7-carboxamide (BTHWA), is an amide derivative of benzothiadiazole, showing plant resistance-inducing activity. This article presents the activity of BTHWA that has led to increased resistance of zucchini (Cucurbita pepo convar. giromontiina) towards viral infections. In addition, since the occurrence of the fungal pathogen, powdery mildew, was also observed during the two-year field experiments, the activity of BTHWA related to the reduction of infection with this fungus was also investigated. The substance was applied in two different variants either four or eight times, over the whole vegetation season. Surprisingly, the variant of four applications performed at the beginning of the vegetation season proved more effective in protection against viruses and fungus. A possible explanation may be the occurrence of the growth-immunity trade-off phenomenon that is known in the literature. Disturbance in plant metabolism resulting from eight applications may lead to lower yields of plants treated with SAR inducers. Perhaps such overstimulation of the plants we treated eight times may not have brought the optimum increase in plant resistance.

Red fluorescent benzothiadiazole derivative loaded in different nanoformulations: Optical properties and their use in bio-imaging

Fluorophores with optimized nonlinear optical properties have become prominent as contrast labels in laser scanning microscopy (LSM). The purpose of this work is to report on a novel benzothiadiazole derivative, namely 4,7-bis(5-((9,9-dioctyl-9H-fluoren-2-yl)ethynyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (EFBT) and its optical performance when it is loaded into organic nanostructures intended as labels for LSM. Four different nanostructured labels were prepared: i) EFBT-loaded silica nanoparticles (SiNPs); ii) folate-bioconjugated SiNPs (SiNPs-FA); iii) EFBT-loaded PEGylated nanoparticles (NPs-PEG); and iv) EFBT-loaded folate-terminated PEGylated nanoparticles (NPs-PEG-FA). All these nanostructures are reported through a comparative study of their linear and nonlinear optical properties, including their performance as exogenous label agents in the cervical cancer cell line HeLa. This assessment of the performance of a specific fluorophore loaded into different nanostructured matrices (labels), and fairly compared under the same characterization conditions, including the LSM settings, is less common while previous reports had focused in comparing silica and PEGylated nanoparticles but loaded with different fluorophores. The results show that the internal molecular organization into each type of organic nanostructure impacted differently the properties of EFBT, where the silica matrix tend to preserve the optical performance of the fluorophore by preventing intermolecular interactions; in contrast, PEGylated nanoparticles favored molecular interactions and introduced non-radiative decay channels that degrades drastically the optical performance. Nevertheless, the use of functionalized ends entities produced a better cellular label uptake with PEGylated that with silica nanoparticles. In overall, the NPs-PEG-FA label produced the best HeLa imaging.

Modulation of halogen-bonded 2D self-assemblies of benzothiadiazole derivative: Concentration and solvent effects

Halogen bonding (XB) with definite directivity and moderate strength like hydrogen bonding has been widely utilized in medical science, organic optoelectronics, and crystal engineering. Whereas, the mechanisms of hetero-halogen bonding (Br···S) induced 2D supramolecular self-assembly are still poorly understood. In this paper, an asymmetrical Br-substituted thiophene-based benzothiadiazole derivative (BTZ-Br) was selected as a building block to explore the self-assembly behaviors driven by XBs using scanning tunneling microscopy (STM). Besides, the short-chain solvents (heptanoic acid and nonanoic acid) and long-chain solvents (n-tridecane and n-tetradecane) were used to study the solvent effect on the BTZ-Br’s assemblies. The BTZ-Br molecules could form frame-like patterns on graphite in all solvents at relatively high concentrations. Whereas, at lower concentration, bamboo-like and linear arrangements were observed in short-chain solvents and long-chain solvents, respectively. Such structural difference is partially caused by the co-absorption of long-chain solvents, which changes the intermolecular bonding mode and stabilizes the molecular arrays via van der Waals forces between BTZ-Br and n-alkanes. Density functional theory (DFT) calculation further confirms the important role of XBs during assembling. This work is helpful for the in-depth understanding of XBs and may provide feasible guidance for the fabrication of novel 2D textures via XBs.

ADOPO‐anchored benzothiadiazole derivative toward efficiently P/N/S synergistic flame retarding of epoxy thermoset

AbstractFlame‐retarded epoxy thermosets are highly desirable for electronics‐related basic materials in the new‐generation information applications. Herein, a DOPO‐anchored benzothiadiazole flame retardant, namelyDOPO‐BTD, is designed and synthesized for P/N/S synergistic flame‐retarded epoxy thermosets.DOPO‐BTDpossesses good thermal stability and excellent compatibility with the epoxy matrix. As reflected by UL 94 test, theDOPO‐BTDcoated EP passes the V0 rating and achieves a higher LOI value of 34.6% at ultralow P content of 0.39 wt%. The investigation of theDOPO‐BTD‐triggered P/N/S synergistic flame‐retarded effect by thermal images further validated the flame retarded efficacy and dramatic inhibition of the flame. Meanwhile, the incorporation of 4.8 wt%DOPO‐BTDinto the epoxy matrix, the PHRR, THR, SPR, TSP, and COP are significantly decreased by 37.97%, 27.44%, 25.49%, 19.83%, and 31.70%, respectively. Additionally, the fire growth index (FGI) is sharply dropped 26.06%. Moreover, the TGIR and TGMS results convince the flame‐retarded mechanism ofDOPO‐BTDthrough the combination of the gas‐phase and condensed‐phase pathways. The P/N/S synergisticDOPO‐BTDcan serve as a promising flame retardant for efficiently fabricating the flame‐retarded epoxy thermosets, and this study sheds light on the development of multiple elements synergistic flame‐retardants for functional polymers with great application potential.

Theoretical enhancement of the electronic and optical properties of a new D-π-A-π-D synthesized donor molecule for a new generation of fullerene-based bulk heterojunction (BHJ) for new organic solar cells devices

Herein, photophysical and electronic properties of a newly synthesized D-π-A-π-D benzothiadiazole derivative referred to ‘R’ molecule, were theoretically improved. Using Density Functional Theory (DFT), and it extended TDDFT methodologies, a news SMi (i = 1–4) benzothiadiazole derivatives are designed and studied by the modification of the acceptor (A) ring. Theoretical calculations show that going from R molecules to SMi ones, an intramolecular charge transfer is obtained. Indeed, the calculated dipole moment variation (μCT) between the ground and the first excited state increases. Consequently, an enhancement of the absorption in the visible part, and a reduction of the calculated optical band gap and the energy gap HOMO-LUMO are obtained. Furthermore, the calculated power conversion efficiency (PCE) factor of the bulk-heterojunction (BHJ) based on the investigated molecules (R and SMi, i = 1–4), as donor material and the fullerene (C60) as an acceptor one, increases drastically from 8% for R molecule to 13.5% for SM3 one according to Marks diagram. Finally, reduced density gradient analysis (RDG) analysis on the SM3-C60 designed composite proves the weak Vander-Waals interactions between the donor SM3 and the chosen acceptor C60.

A π-extended benzothiadiazole derivative for a high-efficiency TADF-sensitized fluorescent organic light-emitting diode.

A new fluorescent emitter based on π-extended benzothiadiazole was synthesized. The emitter exhibited a large molar extinction coefficient, a high quantum yield of 98% and a large radiative decay rate of 108 s-1. Moreover, the obtained TADF-sensitized fluorescent OLED displayed excellent device performance with a high EQEmax of 14.3%.

Modulation of Halogen-Bonded 2d Self-Assemblies of Benzothiadiazole Derivative: Concentration and Solvent Effects

Modulation of Halogen-Bonded 2d Self-Assemblies of Benzothiadiazole Derivative: Concentration and Solvent Effects

Perylene Diimide-Based Multicomponent Metallacages as Photosensitizers for Visible Light-Driven Photocatalytic Oxidation Reaction

Perylene Diimide-Based Multicomponent Metallacages as Photosensitizers for Visible Light-Driven Photocatalytic Oxidation Reaction

Unexpectedly Long Lifetime of the Excited State of Benzothiadiazole Derivative and Its Adducts with Lewis Acids.

We report a study of photoluminescent properties of 4-bromo-7-(3-pyridylamino)-2,1,3-benzothiadiazole (Py-btd) and its novel Lewis adducts: (PyH-btd)2(ZnCl4) and [Cu2Cl2(Py-btd)2{PPO}2]·2C7H8 (PPO = tetraphenyldiphosphine monoxide), whose crystal structure was determined by X-ray diffraction analysis. Py-btd exhibits a lifetime of 9 microseconds indicating its phosphorescent nature, which is rare for purely organic compounds. This phenomenon arises from the heavy atom effect: the presence of a bromine atom in Py-btd promotes mixing of the singlet and triplet states to allow efficient singlet-to-triplet intersystem crossing. The Lewis adducts also feature a microsecond lifetime while emitting in a higher energy range than free Py-btd, which opens up the possibility to color-tune luminescence of benzothiadiazole derivatives.

π-stacked donor-acceptor molecule to realize hybridized local and charge-transfer excited state emission with multi-stimulus response

• The HLCT property based on the ISCT emitter is presented. • The HLCT&ISCT emitter enables multi-stimulus response properties. • High efficiency and exciton utilization in OLEDs are achieved. Organic materials with multi-stimulus response (MSR) properties have magnificent application prospects in the optoelectronics field. Herein, a new asymmetric donor-spiro-acceptor type hybridized local and charge-transfer excited state (HLCT) compound based on benzothiadiazole derivative (2P-BT) moiety, Spiro-2P-BT-TPA , was designed and synthesized. The fluorene unit has a rigid linker to position the acceptor and donor subunit in close vicinity with control over their spacing and molecular structure and to achieve MSR properties, such as quasi-aggregation-induced emission (quasi-AIE), mechanochromic and solvatochromic. Moreover, Spiro-2P-BT-TPA possesses a high photoluminescence quantum yield (PLQY) of 80.9% when it is incorporated in a solid matrix, owing to spatial confined D/A stacked structure, multi-inter/intramolecular interactions as well as quasi-AIE properties. OLEDs based on Spiro-2P-BT-TPA achieve an EQE of 6.6% and the exciton utilization is 40%. To the best of our knowledge, this is a novel example for HLCT materials based on intramolecular spatial charge transfer as well as MSR properties.

Multi-color mechanochromic luminescence of three polymorphic crystals of a donor–acceptor-type benzothiadiazole derivative

The three polymorphic crystals of a donor–acceptor dye exhibited different luminescence colors, which changed in response to mechanical grinding.

White-light emission system based on cyclodextrin/surfactant supramolecular assembly

A multiple luminescence colors system was facile constructed based on the supramolecular assembly of anionic β-cyclodextrin, dodecayltrimethylaminium bromide (DTAB), a naphthalimide dye (G1) and a benzothiadiazole derivative (G2). Significantly, the fabricated system exhibited highly efficient energy transfer from G1 to G2, accompanying by fluorescence color change from blue to yellow, including white light. Furthermore, the white light emission supramolecular assembly was constructed from anionic cyclodextrin with low degree of substitution and DTAB exhibited reversible temperature responsiveness with fluorescent color changes from white to yellow.

Chemical, Metabolic, and Cellular Characterization of a FtsZ Inhibitor Effective Against Burkholderia cenocepacia.

There is an urgent need for new antimicrobials to treat the opportunistic Gram-negative Burkholderia cenocepacia, which represents a problematic challenge for cystic fibrosis patients. Recently, a benzothiadiazole derivative, C109, was shown to be effective against the infections caused by B. cenocepacia and other Gram-negative and-positive bacteria. C109 has a promising cellular target, the cell division protein FtsZ, and a recently developed PEGylated formulation make it an attractive molecule to counteract Burkholderia infections. However, the ability of efflux pumps to extrude it out of the cell represents a limitation for its use. Here, more than 50 derivatives of C109 were synthesized and tested against Gram-negative species and the Gram-positive Staphylococcus aureus. In addition, their activity was evaluated on the purified FtsZ protein. The chemical, metabolic and cellular stability of C109 has been assayed using different biological systems, including quantitative single-cell imaging. However, no further improvement on C109 was achieved, and the role of efflux in resistance was further confirmed. Also, a novel nitroreductase that can inactivate the compound was characterized, but it does not appear to play a role in natural resistance. All these data allowed a deep characterization of the compound, which will contribute to a further improvement of its properties.

Stimuli-Responsive Benzothiadiazole Derivative as a Dopant for Rewritable Polymer Blends.

A new rod-shaped benzothiadiazole fluorophore, namely, 4,7-di-(4-nonylphenyl)benzo[c][1,2,5]thiadiazole, which strongly emits fluorescence both in solution and in solid state has been synthesized, and its photophysical properties were rationalized with the help of density functional theory calculations. This molecule crystallizes in two distinct light-emitting crystalline phases, which can be interconverted in response to pressure, temperature, and solvent vapors. Powder X-ray diffraction indicates that in both polymorph, molecules adopt a lamellar packing, the different interlayer spacing being the main difference between the two structures. Single-crystal analysis of one of the polymorphs allows us to identify weak interaction planes, which presumably facilitates the polymorphic transformation through mechanically or thermally induced sliding processes. The polymorphic transformation and the origin of the switchable fluorescence have been rationalized through a spectroscopic and theoretical study. This study suggests that the different colors observed are due to different intermolecular aromatic interactions owing to the displacement of the molecules with respect to the layer normal. Interestingly, blending this molecule with a biodegradable polymer such as poly(vinyl alcohol) gives rise to a thermally activated reversible switchable fluorescent system, which entitles this material as an attractive candidate for technological applications, such as thermal sensors, security inks, or rewritable paper.