Catalysis-chemistry

Massacci, P. published the artcileBeneficiation of complex semi-oxidized lead-zinc ores, Related Products of catalysis-chemistry, the publication is Industria Mineraria (Rome) (1984), 5(5), 13-21, database is CAplus.

The process of beneficiation of complex oxidized Pb-Zn ores consisted in identifying the deposits, isolating the main Pb and Zn minerals, preparing samples of pure species to test the flotation processes, preparing ores of the oxidized minerals and verifying their degree of liberation, and testing the flotation process on the oxidized ores. Ores containing smithsonite  [14476-25-6] and cerussite  [14476-15-4] are conditioned with Na₂S for better sulfidization of the smithsonite surfaces. This is followed by dilution of the pulp before conditioning with dodecylamine acetate  [2016-56-0], so that the pH is as low as possible.

Industria Mineraria (Rome) published new progress about 2016-56-0. 2016-56-0 belongs to catalysis-chemistry, auxiliary class Active Esterification, name is Dodecylamineacetate, and the molecular formula is C14H31NO2, Related Products of catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Aboal, M. published the artcilePhotoautotrophs and macroinvertebrate trophic relations in calcareous semiarid streams: The role of Cyanobacteria, Computed Properties of 6217-54-5, the publication is Science of the Total Environment (2022), 838(Part_3), 156206, database is CAplus and MEDLINE.

Photoautotrophs and macroinvertebrate trophic relations in Mediterranean streams, especially from semiarid areas, are still poorly known, as is the role of Cyanobacteria, which is the most frequently dominant photoautotroph. To investigate the role of Cyanobacteria as a food resource in these systems, the fatty acid composition of primary and secondary producers was investigated in two streams on a semiarid climatic gradient between 200 and 500 mm of rainfall in SE Spain. Fatty acid composition of photoautotrophs and macroinvertebrates differed among streams in summer and among seasons in each stream. Fatty acid fingerprints show that macroinvertebrates usually fed on the dominant photoautotroph assemblage and that Cyanobacteria represent the main food for all the feeding groups in the Alharabe stream in winter although filamentous green algae were preferred in summer. Only scrapers consuming Chlorophyta displayed a selective feeding behavior. The results show the importance of cyanobacteria as food for all collected macroinvertebrates in winter in some semiarid streams and confirm that fatty acids can be used as temporal and spatial markers in fluvial systems.

Science of the Total Environment published new progress about 6217-54-5. 6217-54-5 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Aliphatic hydrocarbon chain,Metabolic Enzyme,RAR/RXR,Natural product, name is Docosahexaenoic Acid, and the molecular formula is C22H32O2, Computed Properties of 6217-54-5.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Webster, Ian J. published the artcilePhotochemical Synthesis and Spectroscopy of Covalent PAH Dimers, Name: Coronene, the publication is Journal of Physical Chemistry A (2022), 126(7), 1144-1157, database is CAplus and MEDLINE.

Laser photochem. of pressed-pellet samples of polycyclic aromatic hydrocarbons (PAHs) produces covalently bonded dimers and some higher polymers. This chem. was discovered initially via laser desorption time-of-flight mass spectrometry experiments, which produced masses (m/z) of 2M-2 and 2M-4 (where M is the monomer parent mass). Dimers are believed to be formed from photochem. dehydrogenation and radical polymerization chem. in the desorption plume. Replication of these ablation conditions at higher throughput allowed PAH dimers of pyrene, perylene, and coronene to be produced and collected in milligram quantities. Differential sublimation provided purification of the dimers and elimination of residual monomers. The purified dimers were investigated with UV-visible, IR, and Raman spectroscopy, complemented by computational studies using d. functional theory at the CAM-B3LYP/def2-TZV level. Calculations and predicted spectra were calibrated by comparison with the corresponding monomers and used to determine the lowest energy dimer structures. IR and Raman spectroscopy provided few distinctive signatures, but UV-visible spectra detected new transitions for each dimer. The comparison of simulated and exptl. spectra allows determination of the most prevalent structures for the PAH dimers. The work presented here provides interesting insights into the spectroscopy of extended aromatic systems and a new strategy for the photochem. synthesis of large PAH dimers.

Journal of Physical Chemistry A published new progress about 191-07-1. 191-07-1 belongs to catalysis-chemistry, auxiliary class Electronic Materials, name is Coronene, and the molecular formula is C11H21BF4N2O2, Name: Coronene.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Molitor, Sebastian published the artcileSelective Dehydrocoupling of Phosphines by Lithium Chloride Carbenoids, HPLC of Formula: 23897-16-7, the publication is Journal of the American Chemical Society (2014), 136(44), 15517-15520, database is CAplus and MEDLINE.

The development of a simple, transition-metal-free approach for the formation of phosphorus-phosphorus bonds through dehydrocoupling of phosphines is presented. The reaction is mediated by electronically stabilized lithium chloride carbenoids and affords a variety of different diphosphines under mild reaction conditions. The developed protocol is simple and highly efficient and allows the isolation of novel functionalized diphosphines in high yields.

Journal of the American Chemical Society published new progress about 23897-16-7. 23897-16-7 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Dimesitylphosphine oxide, and the molecular formula is C18H23OP, HPLC of Formula: 23897-16-7.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Fuchte, Hanna E. published the artcileA look down the drain: Identification of dissolved and particle bound organic pollutants in urban runoff waters and sediments, Computed Properties of 191-07-1, the publication is Environmental Pollution (Oxford, United Kingdom) (2022), 119047, database is CAplus and MEDLINE.

Urban runoff contains a range of organic micropollutants which, if not removed during wastewater treatment, pose a risk to aquatic environments. These mixtures are complex and often site-specific. Street drains provide an ideal sampling point given they collect the runoff from local and defined catchments. In this study, runoff was collected and sampled in five street drains located in a medium sized town in Germany. A specially constructed trap was used to collect the particulate and total water fractions of the runoff. In addition, passive samplers were deployed to determine the freely dissolved concentrations of selected compounds in the runoff. In sum, 187 polar organic micropollutants could be quantified using LC-HRMS. Thirty of these could only be detected by the use of passive samplers. Traffic derived pollutants such as corrosion inhibitors, rubber- and plastic additives, but also pollutants of industrial origin were strongly represented with sum median concentrations of 100μg/kg dry weight (DW) in the sediment and 400 ng/L in the water fraction. Several of these substances are of concern due to their environmental persistence and mobility. Perfluorinated compounds and pesticides occurred at lower levels of several μg/kg DW sediment or ng/L water. A number of substances including pharmaceuticals, sweeteners and stimulants indicated domestic wastewater influences. Furthermore, a total of 62 parent and alkylated PAHs were quantified by GC-MS and contributed 30-70% to the sum concentrations of the micropollutants. Non-EPA PAHs dominated the carcinogenic PAH toxicity. The increased PAH alkylation indexes (0.7-0.9) showed these primarily came from combustion sources. The runoff particles were addnl. microscopically characterized, and correlations were found between the rubber particle counts and the PAH alkylation-index as well as the levels of 2-(methylthio)benzothiazole, a marker compound for tire leaching.

Environmental Pollution (Oxford, United Kingdom) published new progress about 191-07-1. 191-07-1 belongs to catalysis-chemistry, auxiliary class Electronic Materials, name is Coronene, and the molecular formula is C24H12, Computed Properties of 191-07-1.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Lopez, John published the artcileMissing link: enabling loading of 2-chlorotrityl chloride resin in N-butylpyrrolidinone as a green solvent, Recommanded Product: Fmoc-Pro-OH, the publication is Organic Process Research & Development (2022), 26(5), 1450-1457, database is CAplus.

The 2-chlorotrityl chloride (2-CTC) resin is one of the most frequently used and most versatile resins for the large-scale manufacture of peptides. As a part of our efforts in greening solid-phase peptide synthesis, here, we disclose an efficient procedure for the loading of the first amino acid onto the 2-CTC resin using the green solvent N-butylpyrrolidinone. By applying a design of experiment models, key critical process parameters such as amino acid equivalent and water content were identified. The results obtained suggest that the conditions found can be generalized and applied to any Fmoc-amino acid (Fmoc = 9-fluorenylmethoxycarbonyl). Moreover, they serve as a starting point for the optimization of green resin loading.

Organic Process Research & Development published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Recommanded Product: Fmoc-Pro-OH.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Nudelman, Ayelet published the artcileAcetyl chloride-methanol as a convenient reagent for: A) quantitative formation of amine hydrochlorides B) carboxylate ester formation C) mild removal of N-t-BOC-protective group, Computed Properties of 10517-44-9, the publication is Synthetic Communications (1998), 28(3), 471-474, database is CAplus.

Hydrogen chloride quant. generated in situ by the addition of acetyl chloride to alc. solutions is a useful reagent for carboxylic acid esterification, N-t-Boc deprotection and phosphoramide solvolysis reactions.

Synthetic Communications published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Computed Properties of 10517-44-9.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Thomas, Nicholas C. published the artcilePreparation and Structures of Rare Earth 3-Benzoylpropanoates and 3-Phenylpropanoates, Application of 3-Benzoylpropionicacid, the publication is Australian Journal of Chemistry (2020), 73(12), 1250-1259, database is CAplus.

Rare earth (RE) complexes of 3-benzoylpropanoate (bp), [RE(bp)₃(H₂O)_n] (RE = La, n = 2; RE = Y, Ce, Pr, Nd, Yb, n = 1) and 3-phenylpropanoate (pp), [RE(pp)₃] (RE = Y, La, Ce, Nd, Yb), have been prepared by metathesis reactions between the corresponding rare earth chloride and the appropriate sodium carboxylate. Anal. by single-crystal x-ray diffraction finds that both RE bp and pp complexes favor formation of carboxylate-bridged 1-D coordination polymers in the solid state. Here, the former favors heteroleptic 9 or 10-coordinate complexes (splitting between Ce and La) with the carbonyl remaining uncoordinated but participating as a hydrogen bond acceptor with water in the coordination sphere. Lack of bp carbonyl coordination leaves this group available for surface interactions during corrosion inhibition and complex solubilization. The latter pp derivatives form eight-coordinate complexes for Y and Yb and are the first examples of homoleptic RE pp complexes to be reported.

Australian Journal of Chemistry published new progress about 2051-95-8. 2051-95-8 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ketone, name is 3-Benzoylpropionicacid, and the molecular formula is C18H20N2O12, Application of 3-Benzoylpropionicacid.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Barbero, Margherita published the artcileSynthetic and Mechanistic Aspects of Acid-Catalyzed Disproportionation of Dialkyl Diarylmethyl Ethers: A Combined Experimental and Theoretical Study, Safety of Bis(4-fluorophenyl)methane, the publication is European Journal of Organic Chemistry (2009), 4346-4351, S4346/1-S4346/33, database is CAplus.

The disproportionation reactions of various dialkyl diarylmethyl ethers were carried out in the presence of a catalytic amount (10 mol-%) of o-benzenedisulfonimide as a Broensted acid catalyst; the reaction conditions were mild, and the yields of the diarylmethane target products were good. The catalyst was easily recovered and purified, ready to be used in further reactions. The theor. study confirmed that the reaction proceeds in two steps: The formation of a carbocation from the protonated ether followed by hydride transfer. Although the hydride transfer is the rate-determining step, it is the stability of the carbocation that determines the reaction rate and therefore the yields. (© Wiley-VCH Verlag GmbH and Co. KGaA, 69451 Weinheim, Germany, 2009).

European Journal of Organic Chemistry published new progress about 457-68-1. 457-68-1 belongs to catalysis-chemistry, auxiliary class Fluoride,Benzene, name is Bis(4-fluorophenyl)methane, and the molecular formula is C13H10F2, Safety of Bis(4-fluorophenyl)methane.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Moazezi, Mohammad Reza published the artcileHydrothermal liquefaction of Chlorella vulgaris and catalytic upgrading of product: Effect of process parameter on bio-oil yield and thermodynamics modeling, Application In Synthesis of 6972-05-0, the publication is Fuel (2022), 123595, database is CAplus.

Replacing fossil fuel sources with biofuels is one way to degrade greenhouse gas issuance. Recently, the interest, effort, and investment of researchers around the world in biofuel technol., has been focused on microalgae. The aim of the present work was focused on optimizing the biocrude yield of hydrothermal liquefaction (HTL) of Chlorella vulgaris. The effect of temperature, reaction time and the weight ratio of feedstock in different conditions of hydrothermal liquefaction process has been investigated. Optimization of bio-oil performance was done applying design expert software and response surface method (central composite design). The consequences show that the highest yield of bio-oil was obtained from Chlorella vulgaris (56.21% by weight) at 287 °C, reaction time of 40 min, and microalgae to water ratio of 0.07 Anal. of variance (ANOVA), suggests that the liquefaction temperature and reaction time plays the influential role in the bio-oil yield. Ni-Mo/Al₂O₃ was applied as catalyst for upgrading Bio-oil. The amount of sulfur in bio-oil have completely removed and HHV increased 7% (41.11 MJ/Kg) by using catalyst. Moreover, GC/MS anal. illustrates the number of nitrogenous compounds in bio-oil using Ni-Mo/Al₂O₃ was reduced, so that the amount of pyrazine was changed from 4.25% to 2.10% and pyrrole from 4.75% to 3.11%. To thermodn. modeling and predict the phase behavior of the liquefaction process, manipulation of the UNIFAC coefficients equation was model to minimize the Gibbs free energy. The theor. model had a 9.8% prediction error. This generation of bio-oils is expected to be good support for biofuels.

Fuel published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C3H8N2S, Application In Synthesis of 6972-05-0.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia