2-mercaptobenzothiazole Research Articles

Iron mediated n → π* electron transitions and mid-gap states formation in CN under low-temperature secondary calcination enhances photodegradation of organic pollutants

Iron modified carbon nitride (CN) materials have attracted widespread attention from researchers in different application fields. In this paper, single atom iron anchored CN (FeCN) with mid-gap states and n → π* electron transition was synthesized through low temperature secondary calcination. The mid-gap states introduce surface states capable of trapping photogenerated electrons, enabling FeCN to absorb photons with energies lower than its intrinsic optical bandgap. 10%FeCN also exhibits distinct optical absorption above 490 nm derived from the n → π* electron transition, which expand the visible light response range of photocatalysts and enhance electron transport ability. Additionally, the Fe-Nx site enhances the separation and transmission efficiency of photoexcited charges. The prepared 10%FeCN exhibits extremely high photocatalysis and photo-Fenton activity. Mercaptobenzothiazole (MBT) degradation rate of 10%FeCN is 3.47 times higher than CN, achieving a mineralization rate of 86.7% in 100 min. Additionally, the oxytetracycline hydrochloride (OTC) degradation rate of 10%FeCN in photo-Fenton reaction is 11.9 times higher than CN. After five cycles, this catalyst still has good reactivity, indicating its good stability.

Adsorption of an organic pollutant in to exchanged NaX zeolite: Thermodynamic study

NaX zeolite was modified with copper ions and used for the adsorption of mercaptobenzothiazole (MBT) from aqueous solution. Characterization studies by XRD, DTA/TGA and SEM/EDX confirmed the successful ion exchange and the retention of the zeolite's crystalline structure. XRD results show that the most intense peaks characteristic of 13X persist after the exchange reaction for all samples, with crystallinity ranging from 81 % for the Cu(27)X zeolite to 38 % for the Cu(88)X sample. All exchanged zeolites exhibited optimal MBT adsorption at pH= 6, with adsorption increasing with temperature. It is 195.3 mg/g for the best adsorbent. FTIR and XRD analyses revealed that the adsorption mechanism involves a strong chemical interaction between the nitrogen atom of MBT and the copper ions within the zeolite framework.

Epoxy coating containing CoMOF@MBT metal-organic framework for active protection of aluminum alloy

A new cobalt-based metal-organic framework (CoMOF) was synthesized and subjected to comprehensive characterization employing a range of established techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal analyses. CoMOF was functionalized by loading mercaptobenzothiazole (MBT) onto CoMOF to fabricate CoMOF@MBT with anticorrosion properties. Polarization and immersion tests were employed to estimate the corrosion inhibition ability of CoMOF@MBT in NaCl medium. The results show that it inhibits corrosion of AA2024-T3 aluminum alloy when it is submerged in a NaCl solution with a pH of 3, yielding an inhibition efficiency of 87 %. Protective anticorrosion coatings were prepared by incorporating CoMOF@MBT particles into epoxy resin and coated on AA 2024-T3 substrate. Corrosion resistance of the protective coatings was assessed through the utilization of EIS and salt spray tests and the results show that scratched panels with coating containing CoMOF@MBT exhibit a slow decline in Rct values. It shows an Rct value of 1.45 × 104 Ω cm2 after 48 h of immersion in NaCl medium. The results demonstrated that incorporating CoMOF@MBT improves the capacity of epoxy coatings to withstand corrosion of AA2024-T3 panels in NaCl through the smart release of MBT molecules upon exposure to corrosive agents.

Size-Regulated Metal-Organic Frameworks with Mercaptobenzothiazole for Ga-Based Liquid Metal Encapsulation: A High Performance Oil-Based Additive.

In this study, size-regulated MOFs (MZ) with high MBT loading were successfully synthesized by combining mercaptobenzothiazole (MBT), zinc salt, and 2-methylimidazole (2-MI). Subsequently, the MZ structure was utilized to encapsulate tannic acid-modified gallium-based liquid metal (GLM-TA), thereby acquiring a novel heterogeneous nanocomposite (GLM-TA@MZ). The results revealed that the as-prepared GLM-TA@MZ shows good antiwear and friction-reducing performance as an oil-based lubricant additive, the average friction coefficient was decreased to 0.091, and a wear volume was reduced to 0.95 × 104 μm3, which corresponds to a decrease of 52.3 and 97.2% as compared to base oil PAO. The excellent tribological properties of GLM-TA@MZ can be attributed to physical adsorption on the friction pair, followed by tribochemical reactions. As a result, a thick friction protection film (thickness of about 100 nm) containing Ga, Zn, and S elements was formed, which effectively reduced the contact area between the friction pairs, resulting in improved tribological performance. This study provides insights into the design of MOF-based nanocomposites for lubricating applications.

3-APTES on Dendritic Fibrous Mesoporous Silica Nanoparticles for the pH-Controlled Release of Corrosion Inhibitors.

Mesoporous silica nanoparticles (MSNPs) are currently used in different fields like catalysis, nanomedicine, and conservation science, taking advantage of their high surface area. Here, we synthesized and functionalized mesoporous dendritic fibrous nanoparticles to realize a smart delivery system of protective agents for metals. Different MSNPs were obtained via the microemulsion method followed by a hydrothermal or refluxing treatment at different w/o ratios, times, and temperatures. Dendritic spherical silica nanoparticles with specific features such as an appropriate size (450 nm), a very large surface area (600 m2 g-1), and a high yield synthesis (86%) were selected for surface modification. The fiber surface of the selected MSNPs was functionalized with 3-aminopropyl triethoxysilane (3-APTES). 3-APTES works as a pH-driven "nanogate", suppressing the immediate leakage of the total guest molecule load and modulating the release as a function of pH conditions. Surface-modified MSNPs were tested as a reservoir of the most diffused corrosion inhibitors: Mercaptobenzothiazole (MBT) and 1H-Benzotriazole (BTA); their release properties were studied in solutions with pH = 4 and 7. Functionalized and non-functionalized MSNPs showed a good loading efficiency of guest molecules (34-64%) and a pH-dependent release of the corrosion inhibitors on a timescale of several hours.

Accelerated aging of tire and road wear particles by elevated temperature, artificial sunlight and mechanical stress — A laboratory study on particle properties, extractables and leachables

Tire and road wear particles (TRWP) are generated in large quantity by automobile traffic on roads but their way of degradation in the environment is largely unclear. Laboratory experiments were performed on the effect of elevated temperature (simulating 2–3 years), sunlight exposure (simulating 0.5 years) and mechanical stress on the physical properties and chemical composition of TRWP and of cryo-milled tire tread (CMTT). No significant effects were observed of the applied mechanical stress on mean properties of pristine particles. After sunlight exposure up to 40 % in mass were lost from the TRWP, likely due to the loss of mineral incrustations from their surface. The chemical composition of TRWP and CMTT was characterized by determining 27 compounds, antioxidants (phenylene diamines), vulcanization agents (benzothiazoles and guanidines) and their transformation products (TPs). Extractables of TRWP (580–850 μg/g) were dominated by TPs, namely benzothiazolesulfonic acid (BTSA). CMTT showed much higher amounts of extractables (4600 μg/g) which were dominated by parent chemicals such as N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine (6-PPD), diphenylguanidine (DPG) and mercaptobenzothiazole (MBT). Sunlight exposure affected the amount of extractables more strongly than elevated temperature, for TRWP (−45 % vs −20 %) and CMTT (−80 % vs −25 %) and provoked a clear shift from parent compounds to their TPs. After sunlight exposure extractables of TRWP were dominated by BTSA and DPG. Sunlight exposure drastically reduced the 6-PPD amount extracted from both, TRWP and CMTT (−93 %, −98 %), while its quinone (6-PPDQ) increased by around 1 % of the 6-PPD decrease, only. For many TPs, concentration in leachates were higher than in extracts, indicating ongoing transformation of their parent compounds during leaching. These results highlight that abiotic aging of TRWP leads to strong changes in their chemical composition which affect their particle properties and are of relevance for the environmental exposure to tire-related chemicals.

Indole 3-heterocyclic derivative: A potential antioxidant, antidiabetic agent and their docking study on alpha amylase

α-Amylase enzymes play a crucial role in breaking down starch molecules into simple sugar units that are easily absorbed into the bloodstream, resulting in a sudden increase in blood glucose levels. To respond this effect, there is a need for potent inhibitors that can hinder the enzymatic action of α-amylase. In this regard, indole-3-heterocycles (13−23) were synthesized via functionalizing of 3-(4-chlorobutyl)-1H-indole-5-carbonitrile with different triazoles, tetrazole, thiazole and mercapto benzothiazole with a base. Analytical techniques like 1H, 13C NMR, HRMS and IR spectroscopy characterized the newly synthesized indole heterocycles. These indole compounds functionalized were investigated for antidiabetic properties and antioxidant potentials on varying the side-chain. The synthesized indole compounds exhibited varying inhibition compared to α-amylase standard with IC50 values ranging between 6.44±1.14 μg/mL and 29.27±1.06 μg/mL competing with standard acarbose (IC50 = 5.7 ± 0.99 μg/mL). Among the series of eleven compounds, higher activity of IC50 = 6.44 ± 1.14 μg/mL was exhibited by compound 19 against α-amylase. In addition, an antioxidant potential of IC50 values of 15.62±1.20 μg/mL and 12.00 ± 1.00 μg/mL in 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-casino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, respectively. The binding interactions of indole-3-heterocycles (13–23) were evaluated via in-silico docking performed on 5KEZ enzyme's active site. The current study has shown a light on the potential antidiabetic and antioxidant properties of lead molecules.

Enhanced and selective gold recovery from phone waste: Use of thiosulfate, dissolved oxygen, and an agriculture-based, low-cost adsorbent

Efficient methods were proposed to improve the gold recovery from printed circuit boards (PCBs) in mobile phones. Gold was selectively extracted in the form of Au(S2O3)23− using Na2S2O3-CuSO4-NH3-O2/N2 system. Under optimal conditions (temperature: 25 °C; stirring: 200 rpm; O2/N2: 3.0/0.5 L/min; time: 3 h; Na2S2O3: 160 mmol/L; CuSO4: 120 mmol/L; NH3: 0.7 mol/L (pH 9.9); solid/liquid: 4 g/L), 98% of gold was extracted. The extracted gold was adsorbed by corncob-based activated carbon (CACw), which was prepared using pyrolyzed wood vinegar. The modification of CACw with mercaptobenzothiazole (MBT), forming MBT-CACw, which displayed maximum adsorption efficiency of 49.9 mg/g. The optimal pH for adsorption was found to be 7.5 at 40 °C with 0.2 mol/L (NH4)2S2O3. The adsorption was described by the pseudo-second-order model and the Freundlich isotherm, owing to the high affinity of MBT-CACw for the sulfur donor. Copper was eluted from the loaded MBT-CACw using 0.7 mol/L (NH4)2S2O3 followed by the gold elution with 40% v/v CH3OH. The two-step elution recovered 98.7% of copper and 97.6% of gold. These findings suggest that the oxygen-assisted extraction, combined with the adsorption conducted using low-cost, agriculture-based adsorbent and selective elution, is an eco-friendly approach to efficiently recovering gold from e-waste.

Synthesis and study the biological activity of some six, five and fused ring heteroatome systems derived from 2-mercapto benzothiazole

In this paper ,new series of 2-hydrazino benzothiazole [1], 2-N-benzothiazole-N`-phenyl hydrazine carboxamide [2], 2-N-[(3)-N`-phenyl-5-(p-bromophenyl)-2`-hydroxy-1,3-oxazolin-2`-yl] benzothiazol hydrazine [3] , 2-N-benzothiazole-N`-1-naphthyl hydrazine carboxamide [4], 2-N-[(3`)-N`-(1-naphthyl)-5`-(p-bromo phenyl)-2`-hydroxy-1,3-oxazolin-2`-yl)] benzothiazol hydrazine [5], of 2-thiaacetic acid benzothiazole [6] ,2-thiaacetyl chloride benzothiazole [7], 5-amino-2-mercapto-1,3,4-thiadiazole [8], of 2-mercapto-[5-acetamid thiamethyl benzothiazol]-1,3,4-thiadiazole [9], 2-phenyl-5-chloromethyl-1,3,4-oxadiazole [10],and 2-[5-phenyl-1,3,4-oxadiazol-2`-thiomethyl] benzothiazole [11] have been synthesized. These compounds were characterized by FT-IR , spectrum, elemental analysis and the melting points were checked the purity of the prepared compounds was determined by TLC technique. The biological activity was also studied against Proteus vulgaris (G-) and Staphylococcus aureus (G+) with different concentrations.

Ecological risk assessment of tire and road wear particles: A preliminary screening for freshwater sources in Canada

Abrasion of tires on road surfaces leads to the formation of tire and road wear particles (TRWPs). Approximately 5.9 million tonnes/year of TRWPs are emitted globally, and 12–20% of emissions generated on roads are transmitted into surface waters, where they can release (i.e., leach) chemical compounds that adversely affect aquatic species. To better understand the ecological risk of TRWPs, an acute, probabilistic ecological risk assessment model was developed and applied. This was a screening-level, conceptual ecological risk assessment (ERA) based on secondary data from published scientific studies. The model was demonstrated using British Columbia (BC) Highway 97 (TRWP source) and Kalamalka Lake (receiving water) in Canada, considering two spatial scenarios with varied highway (HWY) lengths and lake volumes. TRWP-derived chemical leachates considered for ERA were aniline, anthracene (ANT), benzo(a)pyrene (B(a)P), fluoranthene (Fl), mercaptobenzothiazole (MBT), and zinc (Zn). An assumed ‘total TRWP-derived leachate set’ was also assessed, representing all compounds present in tire-derived leachate test solutions. The results indicated the risk to aquatic species in two spatial scenarios. In scenario 1, ecotoxicity risk was high from exposure to TRWP-derived zinc and the total TRWP-derived leachate set. Scenario 2 results indicated acute risk was high from all TRWP-derived chemicals examined, except MBT. This preliminary ecological risk screening provides an early signal that freshwater lakes adjacent to busy highways may be at risk from TRWP contamination, indicating a need for further research. This research is the first ERA of TRWPs in Canada, and the results and methodology provide a foundation for future research and solutions development.

ToF-SIMS, XPS and DFT study of the adsorption of 2-mercaptobenzothiazole on copper in neutral aqueous solution and corrosion protection in chloride solution

X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ions mass spectrometry (ToF-SIMS) analyses were performed to characterize the interaction of Cu with mercaptobenzothiazole (MBT) in aqueous solution for 1 h and 24 h in absence and presence of NaCl. The fingerprints of the molecules are identified with XPS (S, N and C signals). The analysis of the Cu 2p core level and Auger Cu peaks allow us to show that the Cu metal is covered by a Cu2O oxide layer whose thickness increases with exposure time in the absence of MBT. It is found that MBT forms multilayers on Cu oxide and inhibits the oxide layer growth. The XPS data are consistent with MBT adsorbed on oxide in multilayers, with a small fraction adsorbed on metallic Cu. These interactions are then further characterized using ToF-SIMS. The results suggest adsorption of the MBT molecules in a strongly bonded layer through both S atoms of the organic molecule oriented towards the surface, covered by a weakly bonded multilayer. Quantitative treatments of XPS intensities allows us to evaluate a layer thickness of 23 Å and 32 Å after 1 h and 24 h, respectively. Co-adsorbed water is also identified. The presence of water in the organic layer (ratio H2O/MBT = 0.28) may explain the orientation of the molecules with S directed towards the surface and N interacting through H bonds with water molecules, as suggested by complementary DFT calculations. The adsorption of MBT is similar in presence of NaCl and in pure water, and also inhibits the oxide growth. In addition, MBT adsorption inhibits the adsorption of Cl on the Cu surface. Inductively Coupled Plasma Optical Emission Spectrophotometry (ICP OES) experiments demonstrate that MBT adsorption inhibits Cu dissolution, even after 20 days immersion in NaCl. Thus, we demonstrated that MBT, by adsorbing and forming a full monolayer at the Cu surface, inhibits further oxide growth, Cl adsorption and copper dissolution in NaCl.

Mass Spectrometry for the Advancement of Lipid Analysis in Alzheimer's Research.

Recent technical advances in mass spectrometry, as applied to the analytical chemistry of lipid molecules, enable the simultaneous detection of the multiplicity of lipid complex species present in the human brain. This, in combination with quantitative studies carried out in plasma samples, helps to identify disease biomarkers including for Alzheimer's disease (AD). Mass spectrometry imaging (MSI) is particularly powerful for the anatomical localization of lipids in brain slices, identifying lipid modifications in postmortem frozen samples from AD patients.Human brain tissues are sectioned in a cryostat and then covered with a chemical matrix, such as mercaptobenzothiazole (MBT) or α-cyano-4-hydroxycinnamic acid (CHCA), to ionize the lipid molecules either by sublimation or by spraying. We describe the use of matrix-assisted laser desorption ionization (MALDI) in an LTQ-Orbitrap-XL mass spectrometer to scan brain tissue slices with high spatial resolution, analyzing 50 μm cell layers. The lipid spectra obtained for each pixel are transformed to color-coded intensity maps of hundreds of lipid species included those within a single tissue slice.

Environmental desulfurization of mine tailings using froth flotation: The case of Amaruq Mine (Nunavut, Canada)

This research examined the the desulfurization of tailings from the Amaruq mine at a laboratory scale using froth flotation. Optimization of the flotation process was carried out by testing the conventional potassium amyl-xanthate collector (PAX) and three alternative collectors from the mercaptobenzothiazole (MBT) and dithiophosphate (DTP) families. The main goal was to assess the efficiency of the desulfurization process as a sustainable tailings management approach to prevent contaminated mine drainage generation. Mineralogical characterization of the Amaruq tailings using automated scanning microscopy (QEMSCAN®) revealed that the total sulfide and carbonate contents were about 8 wt% and 3 wt%, respectively; 63.39 % of the sulfur occurred as pyrrhotite, 30.17 % as pyrite, 3.63 % as gersdorffite, and 2.61 % as arsenopyrite. To compare the collector flotation yields, response surface methodology (RSM) was used for statistical design, analysis, and modelling of froth flotation experiments using three key-parameters: pH, activator (CuSO4) dosage, and collector dosage. Four quadratic mathematical models were developed for each collector to calculate sulfide recovery. Variance analysis (ANOVA) revealed that the factors that most affected sulfide recovery were collector type/dosage and pH. Process optimization yielded a maximum sulfide recovery of 96.73 % using 300 g/t PAX and 300 g/t CuSO4 at pH 11. A similar recovery of 95.83 % was achieved using an MBT-MTP based collector under the same conditions. The maximum recovery obtained using MTP and MTP-DTP based collectors while operating at optimal conditions (alkaline pH and maximum collector dosage at 350 g/t) was 88.65 %. The desulfurization process succeeded in decreasing the sulfur content in the tailings to<0.11 wt%. The final tailings were not acid-forming, as confirmed by the acid-base accounting (ABA) and net acid generation (NAG) static tests, compared to the highly acid-forming feed samples. Kinetic testing on the benign desulfurized tailings was also performed to predict and validate their acid generating potential, as well as their contaminant release rates (particularly As, Ni, Cu, Fe, and Zn). The Amaruq desulfurized material did not present any significant risk of contaminated mine drainage generation, and the leached contaminants did not exceed the criteria set by Quebec provincial legislation.

Alternative flotation collectors for the environmental desulfurization of gersdorffite (NiAsS) bearing mine tailings: Surface chemistry

Environmental desulfurization by froth flotation is a promising technique for the control of acid mine drainage (AMD) and has already been applied in a wide variety of mining operations to prevent environmental risks. This paper aims to address the flotation challenges of gersdorffite for environmental purposes. Gersdorffite, a Ni-As-sulfosalt (NiAsS) frequently encountered in many gold mine wastes, is a major source of contamination. Gersdorffite surface characterization was conducted using diffuse reflectance infrared fourier transform (DRIFT) spectroscopy and optical microscopy, to gain a better understanding of the physicochemical evolution of the mineral surface. The main parameters evaluated were the impact of air-oxidation (aging) and the effect of pH at different values using different reagents (soda ash (NaOH) and lime (CaO)) on the mineral surface chemistry. Collector adsorption behavior was also studied using four collector types as alternatives to xanthate, mainly based on dithiophosphates (DTP) and mercaptobenzothiazole (MBT). Dry grinding of the gersdorffite generated a thin and heterogeneous particle coating mainly composed of arsenic oxides (arsenite and arsenate) and nickel sulfates (NiSO4), with minor elemental sulfur. Hydroxylated Ni species (Ni-OH) were also observed. MBT molecules were found to be the most active compound responsible for the adsorption of the collectors as demonstrated by the adsorption isotherms and the DRIFT spectra. The results of this study have led to a better understanding of gersdorffite surface chemistry before and after the collector adsorption, which should impact its flotation behavior.

Depression Effect of Thioglycolic Acid (TGA) on Flotation Separation of Molybdenite from Copper Sulfides with different Collectors: An Experimental and Theoretical Study

AbstractIn the present study, the depression effect of thioglycolic acid (TGA) on chalcopyrite and pyrite in the presence of different collectors, including potassium ethyl xanthate (PEX), sodium isopropyl xanthate (SIPX), and mercaptobenzothiazole (MBT) in the flotation separation of molybdenite from copper and iron sulfide minerals was evaluated by micro‐flotation and bench‐scale flotation experiments. Surface characterization and adsorption mechanism were investigated by the density functional theory (DFT) method. The flotation experiment results demonstrated that the depression effect of TGA depends on the type of collector applied in the previous stages. DFT calculation provided strong evidence for the results of experiments. It was found that both chalcopyrite and pyrite were effectively depressed in the selective flotation of molybdenite from copper and iron sulfides by TGA when PEX was used as the collector in the bulk flotation stage. It was also found that the use of MBT causes effective flotation of chalcopyrite and molybdenite in the bulk flotation stage, however, its removal from the mineral surface by TGA was not as convenient as PEX.

Research on oxygen solubility in aqueous amine solvents with common additives used for CO2 chemical absorption

Oxidative degradation in amine based post-combustion carbon capture (PCCC) leads to solvent losses and decreased solvent performance. Oxygen (O2) in the flue gas is dissolved into the aqueous solvent and can reactively degrade the amine component. Advanced aqueous amine solvents are designed to contain additional surfactant and anti-foam additives as well as two types of corrosion inhibitors. These additives contribute to improve the solvent performance while reducing foaming and corrosion of expensive equipment. This work examines the impact of these additives on oxygen solubility (or dissolved oxygen - DO) in various aqueous amines used in PCCC including ethanolamine (MEA), 1-amino-2-propanol (A2P), 2-amino-1-propanol (2A1P), 2-(methylamino)-ethanol (NMEA), 2-(ethylamine)-ethanol (2EAE), diethanolamine (DEA), methyl-diethanolamine (MDEA), dimethylethanolamine (DMEA), piperazine (PZ), 1,2-ethyldiamine (EDA), and 1,6 hexadiamine (HDA). The impact of carbon loading on oxygen solubility with and without these additives was also examined. The surfactant and anti-foam additives had minimal impact on DO for all the solvents investigated. The two anti-corrosion additives had opposite effects in the measured DO, 2- mercaptobenzothiazole (MBT) decreased the DO concentration, and sodium metavanadate showed an increase. These results indicate that several of these common additives can be expected to minimally affect DO related oxidative degradation in these advance amine solvents.

Studying the Active Corrosion Inhibition Effect of the Ce3+/2-Mercaptobenzothiazole Loaded NaY Zeolite/Zn-Al LDH Based Containers in a Silane Coating

In the present study, the corrosion protective ability of the sol-gel based composite coatings containing two-different types of the cationic/anionic based inhibitors loaded containers. For this purpose, the NaY zeolite and Zn-Al Layered double hydroxides (LDHs) containers were loaded with Ce3+ cations and 2- mercaptobenzothiazole (MBT) separately. The morphology and composition of the constructed micro/nanocontainers were studied using analytical methods, confirming the successful loading of the inhibitors. In this study, the Ce3+/MBT inhibitors were successfully introduced into the LDH/NaY-based zeolite containers.Results evidenced that the combination of the two inhibitors has a constructive effect on the active protection of the AA2024-T3 sheets. SEM micrographs of the unfilled LDH and stupefaction with MBT show that the prepared LDHs have sheet-like morphology. The addition of single-inhibitor filled containers to the sol-gel hybrid coating, and water-based epoxy coating provided active protection for the AA2024-T3 coated substrate. However, the combination of the filled containers with the inhibitor in the above-mentioned coatings resulted in the improvement of the active protection of the substrate, which confirms the synergy between the particles. The NaY containers loaded with the Ce3+ resulted in a significant increase of the |Z|0.01 Hz of the gel-sol hybrid coatings, which indicates the formation of a stable oxide layer with higher resistance. Whereas the |Z|0.01 Hz of the hybrid sol-gel coatings loaded with LDH-MBT were in the same range as the NaY-Ce loaded coatings, containing NaY-Ce and LDH-MBT, showed the highest |Z|0.01 Hz values that indicate the synergy between the inorganic (Ce3+) and organic (MBT) inhibitors in sol-gel hybrid coatings.

Effect of surfactant micellization on the oxidation of mercaptobenzothiazole by bioinorganic molybdenum complex

A spectrophotometric routine was used to study the effect of surfactant micellization on the oxidation of mercaptobenzothiazole (MBTZ) by bioinorganic molybdenum complex at 301 K and an absorption maxima of 560 nm. It follows an acid dependent oxidative pathway that is medium-sensitive. Charge distribution from the reaction species contributes to the redox retardation, resulting in a downturned primary salt effect with an unenhanced reaction rate. Alteration of the reaction medium with ethanol led to a lowering of oxidation time as the charge catalysis was promoted by a drop in the system permittivity. Likewise, the micellization of cetyltrimethylammonium bromide in the system increased the oxidation rate of the MBTZ due to the high impact of hydrophobic and ion interaction between the micelle and substrates. First order reaction kinetics was observed in the concentration of the redox partners and a 2:2 (complex: MBTZ) stoichiometry was obtained with the involvement of benzothiazyl radical, which resulted in the formation of benzothiazyl disulphide and a Mo2+ deactivated complex. The occurrence of counterion catalysis is pronounced in the reaction system. The standard enthalpy (31.52 ± 0.11 kJ mol−1) and Gibbs energy (74.54 ± 0.13) kJ mol−1 suggest that the process is endothermic dependent. The investigation of surfactant micellization effect on the reaction medium was quantitatively ascertained from the Piszkiewicz model of the complex interaction sequence.

One-pot three-component synthesis of thioether linked 4-hydroxycoumarin-benzothiazole derivatives under ambient condition and evaluation of their biological activity

An efficient and convenient method has been outlined for the synthesis of 3-[(1,3-benzothiazol-2-ylsulfanyl)(phenyl)methyl]-2H-chromen-4-ol derivatives via a one-pot three-component Knoevenagel condensation reaction between 4-hydroxycoumarin, substituted aldehyde, and 2-mercapto benzothiazole in the presence of 10 mol% L-proline as an efficient catalyst in ethanol. The structure of all the newly synthesized chromone derivatives was confirmed by different spectroscopic techniques like IR, 1H NMR, 13C NMR, and LC-MS. Further, all the derivatives were screened for their biological activities such as anti-mycobacterial activity, in vitro antioxidant activity, anticancer activity, and molecular docking studies.

Synthesis, characterization and antibacterial evaluation of novel benzothiazole clubbed acetamide derivatives

A novel series of mercapto benzothiazole derivatives clubbed through acetamide linkage was designed and synthesized which was subjected to antibacterial evaluation using gram positive bacterial strains Staphylococcus aureus and Bacillus subtilis and Pseudomonas aeruginosa and Escherichia coli as gram negative strains. Some of the synthesized compounds showed their excellent antibacterial potential.