Day: November 22, 2022

Time-Resolved Photoelectron Studies of Thiophene and 2,5-Dimethylthiophene was written by Schalk, O.;Larsen, M. A. B.;Skov, A. B.;Liisberg, M. B.;Geng, T.;Soelling, T. I.;Thomas, R. D.. And the article was included in Journal of Physical Chemistry A in 2018.Quality Control of 2,5-Dimethylthiophene The following contents are mentioned in the article:

The photoinduced dynamics of thiophene and 2,5-dimethylthiophene (2,5-DMT) were investigated upon excitation at 200 and 255 nm (2,5-DMT only) using time-resolved photoelectron spectroscopy and compared with results from ab initio coupled cluster calculations For thiophene, depopulation of the initially excited B₂(π₃π₄*) state to the lower-lying A₁(π₂π₄*) state occurs within 25 ± 20 fs, with a subsequent bifurcation into a ring-puckering channel and a ring-opening channel with lifetimes of 80 ± 20 and 450 ± 50 fs, resp. For 2,5-DMT, the dynamics following excitation at 200 nm is described by a monoexponential decay with a time constant of 120 ± 20 fs, while that following excitation at 255 nm is best fit by a biexponential decay with time constants of 115 ± 20 fs and 15 ± 3 ps, resp. The fast signal observed after excitation of 2,5-DMT is assigned to the ring-opening channel, which is favored with respect to thiophene due to a lower excited-state barrier along the ring-opening coordinate and an increased inertia toward the ring-puckering channel. Coupled cluster calculations have been undertaken to compare the relaxation dynamics of thiophene to thiazole and isothiazole. For the latter two mols., we find a strong gradient along the ring-opening coordinate in the Franck-Condon region of the initially populated ππ* state and predict that ring-opening is the dominating relaxation channel after photoexcitation. We use the extracted information for a comparison of the thiophene dynamics with the light-induced processes observed in other five-membered heterocyclic mols. 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 relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. The different substitution patterns in these heterocycles offer new opportunities for drug discovery and other applications in materials science.Quality Control of 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Non-Oxido-Vanadium(IV) Metalloradical Complexes with Bidentate 1,2-Dithienylethene Ligands: Observation of Reversible Cyclization of the Ligand Scaffold in Solution was written by Schlueter, Dirk;Kleemiss, Florian;Fugel, Malte;Lork, Enno;Sugimoto, Kunihisa;Grabowsky, Simon;Harmer, Jeffrey R.;Vogt, Matthias. And the article was included in Chemistry – A European Journal in 2020.Computed Properties of C6H8S The following contents are mentioned in the article:

Derivatives of 1,2-dithienylethene (DTE) have superb photochromic properties due to an efficient reversible photocyclization reaction of their hexatriene structure and, thus, have application potential in materials for optoelectronics and (multi-responsive) mol. switches. Transition-metal complexes bearing switchable DTE motifs commonly incorporate their coordination site rather distant from the hexatriene system. The redox active ligand 1,2-bis(2,5-dimethylthiophen-3-yl)ethane-1,2-dione is described, which reacts with [V(TMEDA)₂Cl₂] to give a rare non-oxido vanadium(IV) species 3(M,M/P,P). This blue complex has two bidentate en-diolato ligands which chelate the V^IV center and give rise to two five-membered metallacycles with the adjacent hexatriene DTE backbone bearing axial chirality. Upon irradiation with UVA light or prolonged heating in solution, the blue compound 3(M,M/P,P) converts into the purple atropisomer 4(para,M/para,P). Both complexes were isolated and structurally characterized by single-crystal x-ray diffraction anal. (using lab source and synchrotron radiation). The antiparallel configuration (M or P helicity) present in both 3(M,M/P,P) and 4(para,M/para,P) is a prerequisite for (reversible) 6π cyclization reactions. A continuous-wave EPR spectroscopic study reveals the metalloradical character for 3(M,M/P,P) and 4(para,M/para,P) and indicates dynamic reversible cyclization of the DTE backbone in complex 3(M,M/P,P) at ambient temperature in solution This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Computed Properties 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. 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.Computed Properties of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Investigation of the limit of discovery using tile-based Fisher ratio analysis with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry was written by Sudol, Paige E.;Ochoa, Grant S.;Synovec, Robert E.. And the article was included in Journal of Chromatography A in 2021.Electric Literature of C6H8S The following contents are mentioned in the article:

Comprehensive two-dimensional gas chromatog. coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) is followed by tile-based Fisher ratio (F-ratio) anal. to investigate the “limit of discovery” for low concentration levels of sulfur-containing compounds in JP8 jet fuel. A mixture of 14 sulfur-containing compounds was spiked at 30 ppm, 15 ppm, 3 ppm and 1.5 ppm into the neat fuel prior to GCxGC-TOFMS anal. with a “reversed” column format (aka polar first dimension (1D) and non-polar second dimension (2D) column). Prior standard implementation of tile-based F-ratio anal. utilized an average F-ratio requiring a min. of 3 mass channels (m/z) with the highest F-ratios. Herein, we explore the notion that use of the top F-ratio m/z for hitlist ranking is superior to the standard implementation for analytes near their limit-of-quantitation (LOQ), defined as an analyte concentration that produces a signal equal to ten times the standard deviation of the baseline noise (10σn). Hitlist ranking comparisons revealed that using only the top F-ratio m/z resulted in impressive improvements in discoverability for the low concentration comparisons. Specifically, for the 3 ppm vs. neat hitlist, 1,4-oxathiane (LOQ = 2.5 ppm) improved from hit 114 via standard F-ratio anal., to hit 25. For the 1.5 ppm vs. neat hitlist, 2-propylthiophene (LOQ = 0.64 ppm) improved from hit 59 to 17, benzo[b]thiophene (LOQ = 1.1 ppm) from hit 98 to 28, and 2,5-dimethylthiophene (LOQ = 1.3 ppm) from hit 262 to 39. Addnl. hitlist ranking comparisons revealed the importance of proper tile size selection, as analyte discoverability deteriorated upon using either an inappropriately too small or too large of a tile. 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 electrophilic substitution of benzothiophene systems is much less regioselective than that of indoles. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, sertaconazole, and also BTCP.Electric Literature of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

The molecular and sulfur isotope distribution of volatile compounds in natural gases and condensates from Alberta, Canada was written by Kutuzov, Ilya;Said-Ahmad, Ward;Turich, Courtney;Jiang, Chunqing;Luu, Nathalie;Jacksier, Tracey;Amrani, Alon. And the article was included in Organic Geochemistry in 2021.Synthetic Route of C6H8S The following contents are mentioned in the article:

Compound-specific S isotope anal. (CSSIA) of volatile organic sulfur compounds (VOSC) in petroleum gases was applied for the first time to two natural gas samples from the Triassic section of the Alberta Basin in Canada. For comparison, CSSIA was conducted for five condensate samples from adjacent wells. The anal. of VOSC in the gas samples revealed similarity in the sulfur isotope composition for thiols, sulfides, and H₂S suggesting an isotopic equilibrium during the reaction between H₂S and hydrocarbons in the reservoir. In contrast, one of the gas samples contained alkyl thiophenes with distinct δ³⁴S values that suggest a different source, probably from oil or bitumen. The mol. and isotopic anal. of condensates revealed several phases of thiol interaction with H₂S bearing similar δ³⁴S value as the H₂S in Gas A and B. Thermally stable OSC such as alkyl-, benzo- and dibenzo- thiophenes of all condensate samples kept their previous δ³⁴S values and not the ones expected in isotopic equilibrium, indicating a recent migration of H₂S to the reservoirs. The δ³⁴S value of the H₂S reacting with the gas and condensate samples is isotopically similar to H₂S which could have generated during complete microbial or thermochem. sulfate reduction of the Charlie Lake anhydrite in the Triassic section, therefore making this process the likely source of the H₂S. This study demonstrates the potential of sulfur isotope anal. of VOSC to interpret origin, migration pathways and provide a relative time frame for in-reservoir processes impacting present day natural gas properties. 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 is also used in the manufacturing of dyes such as thioindigo.Synthetic Route of C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Profile of volatile compounds in frankfurters from culled goat meat during cold storage was written by Pisinov, Boris;Ivanovic, Snezana;Zivkovic, Dusan;Vranic, Danijela;Stajic, Slavisa. And the article was included in Journal of Food Processing and Preservation in 2021.COA of Formula: C6H8S The following contents are mentioned in the article:

The value of culled goat meat can be increased using it in frequently consumed meat products. The evaluation of volatile organic compound (VOC) profiles was conducted in regard to the levels of culled goat meat usage (25%-100%) in frankfurter formulations instead of beef during storage (vacuum-packed, 42 days, 3 ± 1°C). Fifty-two VOC were examined on days 0, 21, and 42. As a result of multidirectional reactions between nonvolatile precursors (influenced by storage conditions), VOC were generated due to lipid oxidation, the Maillard reaction, and interactions between lipid-derived and Maillard-derived products. Differences in the contents of VOC were caused primarily by a higher fat saturation and content of phenylalanine, tyrosine, proline, cysteine and methionine, and reducing sugars in beef compared to culled goat meat. The results suggest that the different compositions and storage had an impact on the profile of VOC in frankfurters. Practical applications : In Mediterranean countries, where the highest goat population is located in Europe, goats are mainly used for milk production, as is the case in Serbia. Increase in the number of goats primarily used for milk production will eventually lead to a higher number of culled animals whose meat has a low com. value. Using goat meat in well-known and frequently consumed meat products, such as frankfurters, certain values may be added to this meat. The results of this research offer an insight into the profile of volatile compounds of frankfurters with different amounts of culled goat meat instead of beef and their changes during storage periods (42 days), providing a more comprehensive picture of the impact of culled goat meat on the characteristics of frankfurters. 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. Benzothiophene is relatively a stable molecule. The core structure is a part of various pharmaceutical substances and natural products. It is also used in the manufacturing of dyes such as thioindigo.COA of Formula: C6H8S

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Black garlic as a substitute for fresh garlic to reduce off-flavor and enhance consumer acceptance and bioactive properties in cemen paste was written by Turan, Emre;Simsek, Atilla. And the article was included in Journal of Food Processing and Preservation in 2022.Safety of 2,5-Dimethylthiophene The following contents are mentioned in the article:

The effects of black garlic aged at different periods as a substitute for fresh garlic (FG) on the overall quality of pastirma cemen paste were evaluated during 90 days of storage. The addition of black garlic increased the phenolic content and antioxidant activities of the cemen pastes, and decreased the firmness, stickiness, pH and color values compared to CON (Control). Total aerobic mesophilic bacteria counts of cemen pastes containing black garlic aged for ≥21 days were similar to those of CON, but the counts of yeast and molds of black garlic added-groups were higher than CON during storage. Incorporation of black garlic to cemen paste increased the content of volatile compounds such as esters and terpenes with fruity and sweet notes, while the concentration of sulfur compounds decreased. In this way, the off-flavor of cemen paste was eliminated and its sensory acceptability improved. Considering the overall data, the best results were obtained in the CP3 group produced with black garlic aged for 21 days. Consequently, black garlic can be used as a substitute for FG to improve the consumer acceptance and bioactive properties of cemen paste. Novelty impact statement : Some consumers avoid pastirma consumption because of the unpleasant off-flavor from cemen paste. Overcoming this problem is very important for both the producer and the consumer. The results of this study showed that black garlic improved the sensory acceptability and bioactive properties of cemen paste by eliminating the unpleasant smell of fresh garlic and increasing the antioxidant capacity. In conclusion, the use of cemen paste with black garlic in pastirma production has promising potential to enhance consumer acceptance and retard oxidative reactions. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Safety of 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. It is found within the chemical structures of pharmaceutical drugs such as raloxifene, zileuton, sertaconazole, and also BTCP.Safety of 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Rapid Dissolution of Cinnabar in Crude Oils at Reservoir Temperatures Facilitated by Reduced Sulfur Ligands was written by Lambertsson, Lars;Lord, Charles J.;Frech, Wolfgang;Bjoern, Erik. And the article was included in ACS Earth and Space Chemistry in 2018.Application In Synthesis of 2,5-Dimethylthiophene The following contents are mentioned in the article:

Mercury (Hg) is present in petrochem. samples, including crude oils, and the processing and use of petroleum products contribute to global Hg emissions. We present a refined theory on geochem. processes controlling Hg concentrations in crude oil by studying dissolution kinetics and solubility thermodn. of cinnabar (α-HgS(s)) in different crude oils held at reservoir temperatures In a black light crude oil, α-HgS(s) dissolved in an apparent zero-order reaction with a rate of 0.14-0.58 μmoles m^-2 s^-1 at 170-230 °C and an estimated activation energy of 43 kJ mol^-1. For crude oil samples with a total sulfur concentration spanning 0.15-2.38% (weight/weight), the measured dissolution rate varied between 0.05 and 0.24 μmoles m^-2 s^-1 at 200 °C. Sep. tests showed that thiols and, to a lesser extent, organic sulfides increased the solubility of α-HgS(s) in isooctane at room temperature compared to thiophenes, disulfides, and elemental sulfur. Long-term (14 days) α-HgS(s) solubility tests in a crude oil at 200 °C generated dissolved Hg concentrations in the 0.3% (weight/weight) range. The high α-HgS(s) dissolving capacity of the crude oils was more than 2 orders of magnitude greater than the highest reported Hg concentration in crude oils globally. On the basis of the kinetic and solubility data, it was further concluded that α-HgS(s) is not stable under typical petroleum reservoir conditions and would decompose to elemental mercury (Hg⁰). Our results suggest that source/reservoir temperature, abundance of reduced sulfur compounds in the crude oil, and dissolved Hg⁰ evasion processes are principal factors controlling the ultimate Hg concentration in a specific crude oil deposit. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Application In Synthesis of 2,5-Dimethylthiophene).

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 is found within the chemical structures of pharmaceutical drugs such as zileuton, raloxifene, and sertaconazole, and also BTCP.Application In Synthesis of 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Using Receiver Operating Characteristic Curves To Optimize Discovery-Based Software with Comprehensive Two-Dimensional Gas Chromatography with Time-of-Flight Mass Spectrometry was written by Reaser, Brooke C.;Wright, Bob W.;Synovec, Robert E.. And the article was included in Analytical Chemistry (Washington, DC, United States) in 2017.Application In Synthesis of 2,5-Dimethylthiophene The following contents are mentioned in the article:

The authors report a quant. approach to optimize implementation of discovery-based software for comprehensive two-dimensional gas chromatog. coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). The software performs a tile-based Fisher ratio (F-ratio) anal. and facilitates a supervised nontargeted anal. based upon the exptl. design to aid in the discovery of analytes with statistically different variances between sample classes. The quant. approach for software optimization uses receiver operating characteristic (ROC) curves. The area under the curve (AUC) for each ROC curve serves as a quant. metric to optimize two key algorithm parameters: the signal-to-noise ratio (S/N) threshold of the data prior to calculating F-ratios at each m/z mass channel and the number of these F-ratios per m/z used to calculate the average F-ratio of a tile. A total of 25 combinations of S/N threshold by number of m/z were studied. Fifty analytes were spiked into a diesel fuel at two concentration levels to produce two sample classes that should in principle produce 50 pos. instances in the ROC curves. The sweet spot for F-ratio anal. is a S/N threshold of 10 coupled with a maximum of the 10 most chem. selective m/z (requiring a min. of 3 m/z), corresponding to an ∼21% improvement in the discrimination of true positives relative to prior studies. This equates to an addnl. 9 true positives being discovered at a false pos. probability of 0.2 and 5 addnl. true positives being found overall. Also, optimization of these software parameters did not depend upon a priori determination of the statistically correct number of pos. instances in the sample classes. The AUC metric appears to be suitable for the evaluation of all data anal. methods that use the proper exptl. design. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Application In Synthesis of 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. Due to its aromaticity, thiophenes do not exhibit the same properties as conventional thioethers.Application In Synthesis of 2,5-Dimethylthiophene

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Identifying Toxicologically Significant Compounds in Urban Wildfire Ash Using In Vitro Bioassays and High-Resolution Mass Spectrometry was written by Young, Thomas M.;Black, Gabrielle P.;Wong, Luann;Bloszies, Clayton S.;Fiehn, Oliver;He, Guochun;Denison, Michael S.;Vogel, Christoph F. A.;Durbin-Johnson, Blythe. And the article was included in Environmental Science & Technology in 2021.Application of 638-02-8 The following contents are mentioned in the article:

Urban wildfires may generate numerous unidentified chems. of toxicity concern. Ash samples were collected from burned residences and from an undeveloped upwind reference site, following the Tubbs fire in Sonoma County, California. The solvent extracts of ash samples were analyzed using GC- and LC-high-resolution mass spectrometry (HRMS) and using a suite of in vitro bioassays for their bioactivity toward nuclear receptors [aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR)], their influence on the expression of genetic markers of stress and inflammation [interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2)], and xenobiotic metabolism [cytochrome P 4501A1 (CYP1A1)]. Genetic markers (CYP1A1, IL-8, and COX-2) and AhR activity were significantly higher with wildfire samples than in solvent controls, whereas AR and ER activities generally were unaffected or reduced. The bioassay responses of samples from residential areas were not significantly different from the samples from the reference site despite differing chem. compositions Suspect and nontarget screening was conducted to identify the chems. responsible for elevated bioactivity using the multiple streams of HRMS data and open-source data anal. workflows. For the bioassay endpoint with the largest available database of pure compound results (AhR), nontarget features statistically related to whole sample bioassay response using Spearman’s rank-order correlation coefficients or elastic net regression were significantly more likely (by 10 and 15 times, resp.) to be known AhR agonists than the overall population of compounds tentatively identified by nontarget anal. The findings suggest that a combination of nontarget anal., in vitro bioassays, and statistical anal. can identify bioactive compounds in complex mixtures This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Application of 638-02-8).

2,5-Dimethylthiophene (cas: 638-02-8) belongs to benzothiophene derivatives. Benzothiophene is used as starting material for the synthesis of bioactive molecules. The core structure is a part of various pharmaceutical substances and natural products. It is also used in the manufacturing of dyes such as thioindigo.Application of 638-02-8

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem

Formation of beef-like odorants from glutathione-enriched yeast extract via Maillard reaction was written by Raza, Ali;Song, Huanlu;Raza, Junaid;Li, Pei;Li, Ku;Yao, Juan. And the article was included in Food & Function in 2020.Product Details of 638-02-8 The following contents are mentioned in the article:

The application of yeast extract (YE) in foods has widely evolved in recent decades. Generally, YE is added to foods because of its characteristic meaty and savory flavor notes. The composition of YE has made it an important ingredient for the production of meat-like flavors. This study focuses on the simulation of beef-like odorants from yeast extract through the Maillard reaction. Addnl., an optimization process was conducted via the central composite design (CCD) to optimize the Maillard reaction conditions. Glutathione-enriched yeast extract (GSH-YE) was utilized as the precursor with the partial addition of cysteine and ribose to form beef-like aroma compounds The key odorants generated through the Maillard reaction were characterized via HS-SPME-GCMS and the contents of the Maillard precursors were analyzed via HPLC. The optimized conditions produced numerous pyrazines, furans, thiazoles, and sulfur- and nitrogen-containing compounds responsible for mimicking beef-like aromas. 2,5-Dimethyl-furan, 2,5-dimethyl-pyrazine, thiazole, 2-methyl-3-furanthiol, di-Me trisulfide, 3,5-diethyl-2-methyl-pyrazine, 3,3-dithiobis[2-methyl-furan] and 2-methyl-3-(methylthio) furan were the predominant odorants generated through the Maillard reaction. Moreover, the individual effect of initial pH and thermal temperature showed dramatic changes in the overall volatile profile. The content of cysteine and other amino acids decreased rapidly at higher thermal temperatures The amount of larger peptides (1500-5000 Da) decreased at a thermal temperature of 160°C, while the contents of smaller peptides (<500) increased. Thus, the sensory and instrumental data validate the potential application of GSH-YE in generating beef-like odorants, and furthermore, these outcomes can aid future pragmatic studies for further insight into beef flavor chem. This study involved multiple reactions and reactants, such as 2,5-Dimethylthiophene (cas: 638-02-8Product Details of 638-02-8).

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.Product Details of 638-02-8

Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem