Day: November 22, 2022

Microbiological versus Chemical Reductive Sulfidation: An Experimental and Theoretical Study was written by Della-Negra, Oriane;Le Cacher de Bonneville, Brieuc;Chaussonnerie, Sebastien;Le Paslier, Denis;Frison, Gilles;Saaidi, Pierre-Loic. And the article was included in ACS Omega in 2021.Recommanded Product: 2,5-Dimethylthiophene The following contents are mentioned in the article:

Microbiol. reductive sulfidation (RS) has rarely been documented, although it represents an efficient strategy for thiol formation. In this work, we reported on the sulfate-respiring bacterium Desulfovibrio sp.86 that has previously demonstrated RS activity toward the pesticide chlordecone. The purpose of this study was to assess its substrate versatility using a set of 28 carbonyls, to compare with chem. RS and to rationalize the observed trends using a dual exptl. and theor. approach. The chem. RS generally proceeds in two steps (S/O exchange using a sulfur donor like P₄S₁₀, reduction of the thione intermediate). Intriguingly, chlordecone was found to be converted into chlordecthiol following the first step. Hence, we designed a protocol and applied it to the 28 substrates to assess their propensity to be directly converted into thiols with the P₄S₁₀ treatment alone. Finally, we performed d. functional theory calculations on these carbonyls and their thiocarbonyl derivatives to build a set of structural, electronic, and thermodn. parameters. The results showed that chem. and microbiol. RS probably involved two distinct mechanisms. Chem., we observed that several carbonyls, possessing electron-withdrawing groups and/or aromatic rings, were directly transformed into thiols in the presence of P₄S₁₀. The correlation obtained with the electron affinity of the thiones led us to conclude that a probable single-electron reductive transfer occurred during the first step. We also found that Desulfovibrio sp.86 transformed a variety of aldehydes and ketones, without ever detecting thiones. No significant correlation was observed with the calculated parameters, but a relationship between aldehyde RS biotransformation and bacterial growth was observed Differences in selectivity with chem. RS open the way for further applications in organic synthesis. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Recommanded Product: 2,5-Dimethylthiophene).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene scaffolds are of great importance due to its increased presence in bioactive molecules. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, sertaconazole, and also BTCP.Recommanded Product: 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Ultra-deep adsorptive removal over hierarchically structured AgCeY zeolite from model gasoline with high competitor content was written by Jiang, Bolong;Zhu, Tianhan;Jiang, Nan;Gong, Mingyue;Yang, Gang;Li, Feng;Song, Hua;Hao, Tianzhen. And the article was included in Journal of Cleaner Production in 2021.Synthetic Route of C6H8S The following contents are mentioned in the article:

Metal-ion-exchanged Y zeolites are a promising adsorptive desufurization (ADS) adsorbent. However, the ADS performance is inhibited significantly by diffusion limitations of sulfur compounds in micropores, especially when refractory sulfur compounds are present in fuels. The aim of this work was to develop a novel highly active, hierarchically structured bimetal Y zeolite and to evaluate the role of mesopores on the ADS performance from fuel oils that contained large amounts of competitors. A mesoporosity was introduced in the NaY by a top-down approach (sequential dealumination-desilication). A hierarchically structured zeolite meso-AgCeY was synthesized by introducing metals, Ag and Ce, by liquid-phase ion-exchange. The prepared meso-AgCeY was characterized and evaluated in terms of ADS performance using gasolines that contained different-sized sulfides and different amounts of toluene or cyclohexene. The adsorption strength was determined by the isosteric heat of adsorption calculations The mesopores centered around 4-30 nm was obtained for meso-AgCeY, with the preservation of the original zeolite structure. Mesopore introduction suppressed the diffusion limitation of sulfur compounds effectively. In addition, transition metal Ag and rare earth metal Ce cations, which can bind organic sulfur compounds through π-complexation and sulfur-metal interaction, resp., provided the meso-AgCeY with a high ADS performance. The meso-AgCeY showed a thiophene ADS capacity of 4.4 or 4.1 times more than that of microporous AgCeY for gasolines that contained large amounts of toluene or cyclohexene, resp. This result may occur because of the suppression of the non-selective mol. adsorption, improvement in mass transfer, full use of active metal sites and strong adsorption energy related with the mesopore introduction. The meso-AgCeY, which combined multiple adsorption metal ions and modified Y zeolite with mesopores, is a promising ADS adsorbent. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Synthetic Route of C6H8S).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is a fused ring compound of thiophene ring and benzene ring, which is an important class of heterocycles with advantageous structures. It has been used as a raw material for the synthesis of biologically active structures and is found in pharmaceuticals such as leukotriene synthesis inhibitors and antifungals, as well as in many natural products.Synthetic Route of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Catalytic thiophene oxidation by groups 4 and 5 framework-substituted zeolites with hydrogen peroxide: Mechanistic and spectroscopic evidence for the effects of metal Lewis acidity and solvent Lewis basicity was written by Bregante, Daniel T.;Patel, Ami Y.;Johnson, Alayna M.;Flaherty, David W.. And the article was included in Journal of Catalysis in 2018.COA of Formula: C6H8S The following contents are mentioned in the article:

Group 4 (Ti and Zr) and 5 (Nb and Ta) atoms substituted into the ^*BEA zeolite framework (M-BEA) irreversibly activate hydrogen peroxide (H₂O₂) and form pools of metal-hydroperoxide (M-OOH) and peroxide (M-(η²-O₂)) intermediates active for the oxidation of 2,5-dimethylthiophene (C₆H₈S), a model reactant representative of organosulfur species in fossil reserves and chem. weapons. Sequential oxidation pathways convert C₆H₈S into 2,5-dimethylthiophene oxide (C₆H₈SO) and subsequently into 2,5-dimethylthiophene dioxide by oxidative dearomatization. Oxidation rates measured as functions of reactant concentrations together with in situ UV-visible spectra show that all M-BEA activate H₂O₂ to form pools of M-OOH and M-(η²-O₂), which then react with either C₆H₈S or H₂O₂ to form the sulfoxide or to decompose into H₂O and O₂, resp. Turnover rates for C₆H₈S oxidation and H₂O₂ decomposition both increase exponentially with the electron affinity of the active site, which is quant. probed via the adsorption enthalpy for deuterated acetonitrile to active sites. C₆H₈S oxidation rates depend also on the nucleophilicity of the solvent used, and rates decrease in the order acetonitrile > p-dioxane ∼ acetone > ethanol ∼ methanol. In situ UV-visible spectra show that highly nucleophilic solvent mols. compete effectively for active sites, inhibit H₂O₂ activation and formation of reactive M-OOH and M-(η²-O₂) species, and give lower turnover rates. Consequently, this work shows that turnover rates for sulfoxidation are highest when highly electrophilic active sites (i.e., stronger Lewis acids) are paired with weakly nucleophilic solvents, which can guide the design of increasingly productive catalytic systems for sulfide oxidation This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8COA of Formula: C6H8S).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.COA of Formula: C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Switchable slow relaxation of magnetization in photochromic dysprosium(III) complexes manipulated by a dithienylethene ligand was written by Kong, Ming;Feng, Xin;Li, Jing;Wang, Jia;Zhang, Yi-Quan;Song, You. And the article was included in New Journal of Chemistry in 2020.Electric Literature of C6H8S The following contents are mentioned in the article:

The photochromic and magnetic properties of two dithienylethene (DTE)-based complexes, [Dy(NO₃)₃(Lo)₂(MeOH)] (1–o) and [Dy(NO₃)₃(Lo)₃] (2–o) (Lo = 4,5-bis(2,5-dimethylthiophen-3-yl)-1,3-dimethyl-1,3-dihydro-2H-imidazol-2-one), were exptl. studied in detail with the help of theor. calculations Both complexes exhibit an instantaneous and strong reversible photochromic response to UV/visible irradiation, as evidenced from spectroscopic tests, and complex 1–o behaves as a typical field-induced single-mol. magnet (SMM). By controlling the reaction ratio of Lo and Dy(NO)₃, Lo replacing a coordinated MeOH mol. in 1–o gave complex 2–o, whose single-mol. behavior is off. Upon irradiation with 254 nm light, the SMM properties of 1–o deteriorate with the energy barrier decreasing from 68.1 to 44.3 K while the magnetic dynamics of complex 2–o shows no response to irradiation Ab initio calculations reveal that the quantum tunnelling of magnetization between the ground Kramers doublets in 2–o is quite strong, leading to the disappearance of SMM behavior. For complex 1–o, the strong magnetic anisotropy and moderate quantum tunnelling of magnetization relative to 2–o give rise to an appropriate energy barrier for SMM. However, the decrease in energy barriers for 1–o after irradiation results from the weakening of magnetic anisotropy, which is caused by the stronger charge delocalization of the coordinated carbonyl O atom of the ring-closed DTE ligand. By regulating the reactant ratio, two photochromic DTE-based Dy(III) complexes were obtained and the SMM properties of complex 1–o can be tuned by the light-induced isomerization of the dithienylethene ligand. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Electric Literature of C6H8S).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene finds use in research as a starting material for the synthesis of larger, usually bioactive structures. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Electric Literature of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Fundamental research on the influence of mercaptan and thioether structure on the solvent extraction of fluid catalytic cracking naphtha was written by Zhang, Yuhao;Liu, Mengqi;Liu, Mengmeng;Zhao, Liang;Gao, Jinsen;Xu, Chunming;Gao, Xuhui;Liu, Xiangqi. And the article was included in Separation and Purification Technology in 2021.Recommanded Product: 2,5-Dimethylthiophene The following contents are mentioned in the article:

The thioether and mercaptan components (over 50-100 mg/kg) of fluid catalytic cracking (FCC) naphtha must be removed to satisfy the rigorous sulfur content standard of the vehicle gasoline. Owing to the difference between the structures of thioether and mercaptan and that of thiophenic sulfur, the desulfurization process is usually divided. A serious loss of octane number (ON) occurs during typical desulfurization when the sulfur content is reduced to 10 mg/kg. With the oriented separation of FCC naphtha critical components process, the standard of sulfur content with losing 1 unit of ON can be satisfied. However, thioether and mercaptan require individual technologies for removal. Thioether, mercaptan, and thiophenic sulfur must be synchronously removed to improve the efficiency, simplify the technol., and reduce the energy consumption. In this study, quantum chem. calculation and ternary liquid-liquid equilibrium experiment were combined to investigate the effect of thioether and mercaptan structures on the sulfoxide solvent extraction performance. The results showed that the Van der Waals′ force was the main interaction between the thioether/mercaptan and the solvent because the peaks of solvent and sulfide by RDG anal. were located at -0.01 to 0.01 a.u. In addition, the dipole moment, steric hindrance, and displacement affected the solvent extraction performance. The selectivity coefficient θ of C3 thioether and mercaptan was 5.80 and 6.48 by DMSO solvent, resp., which were greater than those of C4 sulfides (4.48 and 5.56). The interaction energy Eint of DMSO-Et Me sulfide and DMSO- propanethiol were -32.75 and -33.68 kJ/mol while DMSO-diethyl sulfide and DMSO- butanethiol were -24.72 and -29.20 kJ/mol. It also proves that the C3 thioether and mercaptan could better extract into the solvent. In this way, the extractive desulfurization rate of the real FCC naphtha by DMSO was 80%. Therefore, the use of sulfoxide composite solvent can simultaneously extract the thioether, mercaptan, and thiophenic sulfur. This anal. method could be used to predict the synchronous extraction performance for FCC naphtha sulfides by other typical solvents. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Recommanded Product: 2,5-Dimethylthiophene).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophenes are valuable heterocycles that are widely used in medicines, agrochemicals, and materials science. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Recommanded Product: 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Enhancing the chemical selectivity in discovery-based analysis with tandem ionization time-of-flight mass spectrometry detection for comprehensive two-dimensional gas chromatography was written by Freye, Chris E.;Moore, Nicholas R.;Synovec, Robert E.. And the article was included in Journal of Chromatography A in 2018.Electric Literature of C6H8S The following contents are mentioned in the article:

The complementary information provided by tandem ionization time-of-flight mass spectrometry (TI-TOFMS) was studied for comparative discovery-based anal., when coupled with comprehensive two-dimensional gas chromatog. (GC × GC). The TI conditions implemented were a hard ionization energy (70 eV) concurrently collected with a soft ionization energy (14 eV). Tile-based Fisher ratio (F-ratio) anal. was used to analyze diesel fuel spiked with twelve analytes at a nominal concentration of 50 ppm. F-ratio anal. is a supervised discovery-based technique that compares two different sample classes, in this case spiked and unspiked diesel, to reduce the complex GC × GC-TI-TOFMS data into a hit list of class distinguishing analyte features. Hit lists of the 70 eV and 14 eV data sets, and the single hit list produced when the two data sets are fused together, are all studied. For the 70 eV hit list, eleven of the twelve analytes were found in the top thirteen hits. For the 14 eV hit list, nine of the twelve analytes were found in the top nine hits, with the other three analytes either not found or well down the hit list. As expected, the F-ratios per m/z used to calculate each average F-ratio per hit were generally smaller fragment ions for the 70 eV data set, while the larger fragment ions were emphasized in the 14 eV data set, supporting the notion that complementary information was provided. The discovery rate was improved when F-ratio anal. was performed on the fused data sets resulted in eleven of the twelve analytes being at the top of the single hit list. Using PARAFAC, analytes that were discovered were deconvoluted to obtain their identification via match values (MV). Location of the analytes and the F-ratio spectra obtained from F-ratio anal. were used to guide the deconvolution. Eight of the twelve analytes where successfully deconvoluted and identified using the inhouse library for the 70 eV data set. PARAFAC deconvolution of the two sep. data sets provided increased confidence in identification of discovered analytes. Herein, the authors explore the limit of analyte discovery and limit of analyte identification, and demonstrate a general workflow for the study of key chem. features in complex samples. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Electric Literature of C6H8S).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. It has been used as a raw material for the synthesis of biologically active structures and is found in pharmaceuticals such as leukotriene synthesis inhibitors and antifungals, as well as in many natural products.Electric Literature of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Study of thermal maturation processes of sulfur-rich source rock using compound specific sulfur isotope analysis was written by Rosenberg, Yoav O.;Meshoulam, Alexander;Said-Ahmad, Ward;Shawar, Lubna;Dror, Guy;Reznik, Itay J.;Feinstein, Shimon;Amrani, Alon. And the article was included in Organic Geochemistry in 2017.Recommanded Product: 2,5-Dimethylthiophene The following contents are mentioned in the article:

Semi-open pyrolysis experiments were conducted on a thermally immature, organic and sulfur-rich source rock (Ghareb Formation, Israel). Structural and sulfur isotope ratio (³⁴S/³²S) changes in specific organic sulfur compounds were studied along with bulk sulfur phases (H₂S, kerogen, oil) during thermal maturation and oil formation. Oil, gas and rock samples were collected sequentially at several points along the maturation path and were analyzed. In addition, four natural crude oils from Israel were analyzed and the results were compared to the pyrolytic oils.The results showed relatively large δ³⁴S variability (∼10‰) of the organic sulfur compounds (OSCs) in the bitumen of the unheated rock and first pyrolytic oil. This variability was probably a remnant of the original sulfur isotopic signature acquired during the sulfurization of the organic matter in the early diagenetic process. At later stages of thermal maturation, the variability of the sulfur isotopic values in the kerogen gradually decreased to ∼2‰. Three mechanisms were suggested to explain the structural changes and isotopic fractionations of OSCs in the kerogen and generated oils: (A) Cleavage of weak S-S and C-S bonds leading to the release of large amounts of H₂S and to cyclization of the precursors in the kerogen with small fractionations. Thus, the OSCs released by this mechanism preserved their distinct δ³⁴S values. (B) Re-reaction of the released S species with hydrocarbons and generation of new OSCs within the kerogen (or bitumen) matrix. (C) Cleavage of stronger C-C bonds and transformation of OSCs to create more stable compounds (e.g. dibenzothiophenes) from multiple sulfur sources. Mechanisms (B) and (C) homogenized the δ³⁴S values of the different OSCs which reflected that of the bulk kerogen.The bulk organic sulfur phases (bitumen, oil, kerogen) were ³⁴S enriched by < 1‰ despite large amounts of ³⁴S-depleted H₂S (53% of total S) that was released continuously (“open system”). Therefore, the preferential loss of H₂S during thermal maturation may not be responsible to the ³⁴S enrichment of oils as reported in some petroleum basins. The overall outcome of the maturation process yields OSCs with δ³⁴S values that closely reflect the kerogen and can be used as a fingerprint for oil-oil and oil-source rock correlation over wide ranges of thermal maturity. The applicability of such correlation is demonstrated by the very good correlation of δ³⁴S values of specific OSCs between artificial and natural oil samples. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Recommanded Product: 2,5-Dimethylthiophene).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is a fused ring compound of thiophene ring and benzene ring, which is an important class of heterocycles with advantageous structures. It is found within the chemical structures of pharmaceutical drugs such as zileuton, raloxifene, and sertaconazole, and also BTCP.Recommanded Product: 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Experimental and theoretical study on the formation of volatile sulfur compounds under gas reservoir conditions was written by Meshoulam, Alexander;Said-Ahmad, Ward;Turich, Courtney;Luu, Nathalie;Jacksier, Tracey;Shurki, Avital;Amrani, Alon. And the article was included in Organic Geochemistry in 2021.Quality Control of 2,5-Dimethylthiophene The following contents are mentioned in the article:

Volatile organic sulfur compounds (VOSC) are found in petroleum natural gas and condensates at trace levels. The abundance and δ34S values of VOSC were proposed as a proxy for thermal processes such as oil and gas generation during thermal maturation, thermochem. and microbial sulfate reduction, migration and expulsion. The understanding of VOSC formation and degradation mechanisms is needed to refine the use of δ ³⁴S values of VOSC as proxies for thermal processes over geol. timescales in the subsurface. We therefore conducted pyrolysis experiments at 360 °C for 4, 12 and 72 h using pentane and H₂S or pentanethiol as model compounds to study the formation and degradation pathways of VOSC and associated variations in δ ³⁴S values. The main products of these experiments are C₁-C₄ alkanes along with a variety of thiols and thiophenes, the most dominant VOSC formed. Most thiols were in equilibrium with H₂S after 4 h based on their δ ³⁴S values. Thiophenes were first 34S depleted relative to H₂S and only reached equilibrium at the 72 h experiment The products and 34S fractionations in the pyrolysis experiment of pentanethiol at 360 ° C and 12 h were similar to those of the experiment with H₂S and pentane at the same conditions. This similarity suggests that pentanethiol is an intermediate product in the formation of aromatic VOSC during pyrolysis of pentane and H₂S. Benzo- and dibenzothiophenes (BTs and DBTs) were formed in the liquid phase and their 34S depleted values relative to H₂S indicated that they had not reached equilibrium Ab-initio calculations of the thermodn. properties of thiols, thiolanes, thiophenes BTs and DBTs were used to explain the relative abundance of products in the system and predict their abundance and S isotopic signature at reservoir conditions. The thermodn. data suggests that at equilibrium, only small quantities of thiols and even smaller quantities of thiolanes can exist under our exptl. conditions. Unlike thiols, the free energy of formation of thiophenes, BTs and DBTs is neg. under these conditions indicating that the formation of these compounds is thermodynamically favored. The result suggests that the δ 34S values of thiols are controlled by a very rapid equilibrium isotopic effect (EIE). On the other hand, aromatic sulfur compounds can preserve the δ34S value of the kinetic isotopic effect (KIE) associated with their formation for longer. However, under typical petroleum reservoir conditions, the formation of aromatic VOSC in the gas phase from short alkanes (<C5) and H₂S is not thermodynamically preferred and thus their presence is expected to be either as kinetic products or due to influx and charge from a different source where the reactions were thermodynamically favorable. Thus, the abundance and Δ ³⁴S between H₂S and VOSC can be used as a new approach to evaluate charge history within sulfur containing reservoirs. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Quality Control of 2,5-Dimethylthiophene).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is a fused ring compound of thiophene ring and benzene ring, which is an important class of heterocycles with advantageous structures. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, and sertaconazole, and also BTCP.Quality Control of 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem