Oxygen Sulfide Research Articles

Synthesis of sulfone bridged 2D porphyrin assembly for enhanced photocatalytic oxygenation of sulfide

In the present work, we have synthesized sulfone-bridged tetraphenyl porphyrin, 2D polymer ‘P’ (C44H28N4OySx)n through a one-pot reaction of tetra(p-bromophenyl) porphyrin, S with sulfur powder in DMF. The polymer ‘P’ has been further reacted with erythrosine B for the fabrication of composite photocatalyst, C (C65H37N4NaOySx)n using donor– acceptor conjugation protocol. Herein, both compounds (P & C) have been well characterized by MAS 13C-NMR, XPS, IR, powder XRD, TGA, SEM-EDX, UV-Vis spectra, and Cyclic Voltammetry. Due to the low HOMO-LUMO band gap energy, the applicability of the composite photocatalyst (C, 2.1 eV) has been studied in terms of oxidation of sulfide to sulfoxide. The present work shows a promising route for the development of sulfone-bridged 2D porphyrin covalent organic framework (COF) and its composite photocatalyst as well as its usage in photocatalytic sulfoxidation reaction.

Exploring an Electrochemical Route for Water-Enhanced Oxygenation Reactions Utilizing Nickel Molecular Structures: A Case Study.

Recently, Ni molecular catalysis has been extensively applied in oxygenation reactions. This work is underpinned by the characterization techniques and the discovered instability of the Ni-bipyridine/phenanthroline system, which results in Ni (hydr)oxide production under oxidative conditions. The practical applications of this mechanism by employing a prepared Ni (hydr)oxide-based electrode specifically in the oxygenation of sulfides, achieving noteworthy yields in contrast to noncatalyst control experiments, are explored. Thus, a Ni (hydr)oxide-based material is proposed as a candidate for the true catalyst for sulfide oxidation in the presence of the Ni-bipyridine/phenanthroline system. The findings of this study are expected to stimulate discussion and encourage new viewpoints within the chemical community regarding the potential applications and mechanisms of molecular catalysts in oxidation reactions.

Photocatalytic oxygenation of sulfide using solar light and ingenious GQDs@AQ catalyst: Mechanistic and synthetic investigations.

The combination of excellent electronic properties and thermal stability positions orange-derived graphene quantum dots (GQDs) as promising materials for solar light-based applications. Researchers are actively exploring their potential in fields such as photovoltaics, photocatalysis, optoelectronics, and energy storage. Their abundance, cost-effectiveness, and eco-friendly nature further contribute to their growing relevance in cutting-edge scientific research. Furthermore, only GQDs are not much more effective in the UV-visible region, therefore, required band gap engineering in GQDs material. In this context, we designed GQDs-based light harvesting materials, which is active in UV-visible region. Herein we synthesized GQDs coupled with 2,6-diaminoanthrquninone (AQ), that is, GQDs@AQ light harvesting photocatalyst the first time for the oxidation of sulfide to sulfoxide under visible light. For the integrating reactions of sulfide in aerobic conditions under visible light by GQDs@AQ photocatalyst exhibit utmost higher photocatalytic activity than simple GQDs due to low molar extinction coefficient and slow recombination charges. The use of GQDs@AQ light harvesting photocatalyst, showed the excellent organic transformation efficiency of sulfide to sulfoxide with excellent yield (94%). The high efficiency and excellent yield of 94% indicate the effectiveness of GQDs@AQ as a photocatalyst for these specific organic transformations.

Supergene Hydrous Sulfates in the Tuolugou Co-Au Deposit, Northern Qinghai–Tibet Plateau: Implications for Genetic Mechanism and Exploration

Supergene hydrous sulfate minerals form through the oxygenation and weathering of primary sulfides. In the Qinghai–Tibet Plateau region, with an alpine and dry environment, hydrous sulfate minerals oxidized from pyrite-bearing ore bodies provide important clues regarding the mineralization and environment. The Tuolugou sedimentary-exhalative (SEDEX) Co-Au deposit is located in the East Kunlun metallogenic belt of the northern Qinghai–Tibet Plateau in China. In the mining district, pyrite is the prevalent Co-hosting sulfide mineral, and is partially exposed on the surface to weathering and oxidation. Herein, we document the mineral assemblages in the supergene oxidation zone in the Tuolugou deposit, probe the genesis of supergene assemblage, and explore the implications for exploration. Three zones can be recognized in the oxidation zone of the Tuolugou deposit, including the outer zone (natrojarosite), intermediate zone (rozenite and aplowite), and inner zone (roemerite and melanterite). The mechanism of oxidation under aerobic and anaerobic conditions, as well as zoning with different oxidation degrees, are described in detail. Hydrous sulfates such as natrojarosite can be used as possible indicators of the exploration of albitite-related SEDEX deposit in this region.

Symmetry-dependent photocatalysis of conjugated microporous polymers based on pyrene for oxygenation of sulfides with O2

To date, conjugated microporous polymers (CMPs) have been developed into multifaceted photocatalysts. Here, two CMPs based on pyrene with the linkages of thiazolo[5,4-d]thiazole (TzTz) are prepared for visible light photocatalysis. The dimension of the molecular building block’s symmetry on the property and activity of CMPs is systematically investigated. Py(4)-TzTz-CMP with a pyrene building block of D2h symmetry gives rise to better optoelectronic property than Py(2)-TzTz-CMP with a pyrene building block of C2 symmetry. Therefore, Py(4)-TzTz-CMP photocatalyst is endowed with superior conversions for the green light-promoted oxygenation of sulfides with O2. Intriguingly, mechanistic explorations disclose that both superoxide and singlet oxygen are responsible for the production of the target sulfoxides. This work gives insight into the rational design of highly active CMP photocatalysts for selective chemical transformations.

Changing Sub‐Surface Chemistry Resulting From a 26‐Million‐Year Unconformity: Porewater Chemistry From IODP Site U1553 in the South Pacific

AbstractWhereas changes in pore water chemistry are known to impact carbonate sediment geochemistry, little is known about the impact of long unconformities on carbonate alteration. IODP Site 378‐U1553 on the southern Campbell Plateau, with a 26‐million‐year, erosional unconformity, provides a key location for examining the impact of long‐term unconformities on sub‐surface chemistry and carbonate archives. This study examined 76 interstitial water samples for sulfate sulfur and oxygen isotopes, as well as 28 bulk carbonate samples for carbonate associated sulfate (CAS) sulfur isotopes, to quantify the effects of this unconformity on the sub‐surface redox chemistry of the Site. The current state of the system suggests limited influence of redox processes on the CAS archive. Manganese reduction reaches 30 mbsf, with a decrease in manganese reduction between 20 and 30 mbsf. Below 30 mbsf, the system transitions to iron reduction to a depth of approximately 140 mbsf where sulfate reduction begins. Dissolved sulfate sulfur and oxygen isotope values suggest repeated oxygenation of sulfides. The CAS record from the Site deviates from previously published seawater values. However, the lack of a relationship between the dissolved sulfate and CAS records suggests most of the alteration of the CAS record likely occurred before the unconformity when the carbonate sediments were more reactive. This further supports the CAS record as a relatively robust archive, withstanding most post‐depositional mechanisms of carbonate alteration.

Solvent‐Polarity‐Induced Assembly of Calixarene‐Capped Titanium‐Oxo Clusters with Catalytic Activity in the Oxygenation of Sulfides

AbstractFour calixarene‐coordinated titanium‐oxo clusters, namely, [Ti4(C6A)2(μ3‐O)2(DMF)2] (CIAC‐258), [Ti8(H3C6A)4(C6H5PO3)8(μ2‐O)4]4− (CIAC‐259), [Ti6(TC4A)3(μ2‐O)3 (OiPr)6] (CIAC‐260) and [Ti6(H2TC4A)4(C6H5PO3)4(μ2‐O)5(DMF)2]2− (CIAC‐261) were obtained, which feature sandwich‐like, windmill‐like, triangular, and tetrahedral structures, respectively. The polarity of the solvent determines the involvement of the auxiliary ligand phenylphosphonic acid in the formation of the products and their structures. Compounds CIAC‐258 and CIAC‐261 exhibit good catalytic performance in the selective oxidation of sulfides to sulfoxides with H2O2 as the oxidant, which can be attributed to the Ti active sites coordinated by exchangeable DMF molecules. Moreover, density functional theory (DFT) calculations revealed that the Ti‐hydroperoxo species formed by the interaction of the Ti active site in CIAC‐258 or CIAC‐261 and H2O2 is the most likely catalytic active component during the catalytic sulfoxidation process.

Zr-Based Metal-Organic Frameworks with Phosphoric Acids for the Photo-Oxidation of Sulfides.

Heterogeneous Brønsted acidic catalysts such as phosphoric acids are the conventional activators for organic transformations. However, the photocatalytic performance of these catalysts is still rarely explored. Herein, a novel Zr-based metal-organic framework Zr-MOF-P with phosphoric acids as a heterogeneous photocatalyst has been fabricated, which shows high selectivity and reactivity towards the photo-oxidation of sulfides under white light illumination. A mechanism study indicates that the selective oxygenation of sulfides occurs with triplet oxygen rather than common reactive oxygen species (ROS). When Zr-MOF-P is irradiated, the hydroxyl group of phosphoric acid is converted into oxygen radical, which takes an electron from the sulfides, and then the activated substrates react with the triplet oxygen to form sulfoxides, avoiding the destruction of the catalysts and endowing the reaction with high substrate compatibility and fine recyclability.

Low‐Voltage‐Driven Electrochemical Aerobic Oxygenation with Flavin Catalysis: Chemoselective Synthesis of Sulfoxides from Sulfides

AbstractThe chemoselective electrochemical oxygenation of sulfides to sulfoxides is performed using a biomimetic flavin catalyst that enables the activation of molecular oxygen under a low cathode potential. Diverse functional groups, including alcohols, ketones, aldehydes, cyclopropane, carboxylic acids, pyridine, alkenes, and alkynes, are well tolerated under low‐voltage electrolytic conditions.magnified image

Cerium-oxo clusters for photocatalytic aerobic oxygenation of sulfides to sulfoxides.

Two cerium-oxo clusters (COCs) 1 and 2 are constructed by self-assembly of cerium ions and carboxylate ligands. Both clusters feature spherical structures resembling the key moiety of fluorite phase CeO2, and 1 exhibits high activity and selectivity for the photocatalytic aerobic oxygenation of sulfides to sulfoxides based on the switch between the Ce(IV/III) redox couple.

Sulfide Oxidation by 2,6-Bis[hydroxyl(methyl)amino]-4-morpholino-1,3,5-triazinatodioxomolybdenum(VI): Mechanistic Implications with DFT Calculations for a New Class of Molybdenum(VI) Complex.

Sulfide oxidation is accomplished by a new class of dioxomolybdenum(VI) catalyst (1) that uses the tridentate 2,6-bis[hydroxyl(methyl)amino]-4-morpholino-1,3,5-triazine ligand to form a five-coordinate molybdenum(VI) center. Resonance Raman spectra show that the dioxo groups on the Mo(VI) oxygens readily exchange with water in an acetonitrile media that allows 18O labeling of catalyst 1. The model oxidation reaction was the conversion of thioanisole (2) to the corresponding sulfoxide with 4% of 1 using an equimolar amount of H2O2 in MeCN-d3. Oxygen-18 labeling experiments with either 18O-labeled 1 or 18O-labeled H2O2 are consistent with a sulfide oxygenation pathway that uses a η1-Mo(OOH) hydroxoperoxyl species (3). The hypothesized intermediate 3 is initially formed in a proton transfer reaction between 1 and H2O2. Oxidation is hypothesized via nucleophilic attack of the sulfide on 3 that is supported from a Hammett linear free-energy relationship for para-derivatives of 2. A Hammett reactivity constant (ρ) of -1.2 ± 0.2 was obtained, which is consistent with other ρ values found in prior sulfide oxidation reactions by group 6 complexes. An Eyring plot of the 2 oxidation by 1 gives an Ea of 63.0 ± 5.2 kJ/mol, which is slightly higher than that of a similar oxidation of 2 by the molybdenum(VI) complex, oxodiperoxo (pyridine-2-carboxylato)molybdate(VI) bis(pyridine-2-carboxylic acid) monohydrate (5). Computational modeling with density functional theory (DFT) of the complete reaction profile gave enthalpy and entropy of activations (64 kJ/mol and -120 J/mol·K, respectively) within 1 standard deviation of the experimental values, further supporting the hypothesized mechanism.

Electrochemical oxygenation of sulfides with molecular oxygen or water: switchable preparation of sulfoxides and sulfones.

A practical and eco-friendly method for the controllable aerobic oxygenation of sulfides by electrochemical catalysis was developed. The switchable preparation of sulfoxides and sulfones was effectively controlled by reaction time, in which both molecular oxygen and water can be used as the oxygen source under catalyst and external oxidant-free conditions. The electrochemical protocol features a broad substrate scope and excellent site selectivity and is successfully applied to the modification of some sulfide-containing pharmaceuticals and their derivatives.

Synergistic cooperative effect of CF3SO2Na and bis(2-butoxyethyl)ether towards selective oxygenation of sulfides with molecular oxygen under visible-light irradiation

A practical method for the switchable synthesis of sulfoxides and sulfones through visible-light-initiated CF3SO2Na/2-butoxyethyl ether synergistic catalyzed oxygenation of sulfides was developed.

CORROSION PROTECTION OF OIL AND GAS FIELD EQUIPMENT

The article considers the main types of processes that lead to corrosion of the chemical composition of raw materials that were obtained in the development of oil and gas fields.The graph shows the influence on corrosion rates of steels with different quantitative ratio of layer and fresh water (salt concentration) and speed of environment motion (oxygen). Corrosion aggressiveness of two-phase environmentally-determined physico-chemical propertiesof the hydrocarbon and water components of the system, their composition, quantitative ratio, the presence of dissolved gases (hydrogen sulfide oxygen carbon dioxide). Corrosion of metals is the spontaneous destruction of metals due to their chemical or electrochemical interaction with the external environment. When a metal is subjected to corrosion, there is not only a loss of its mass, but also a decrease in its mechanical strength, elasticity and other properties. Metal corrosion causes significant damage to the economy. For the conditions of oil and gas production enterprises, metal corrosion of oil equipment and Communications is characterized by a number of features. First of all, it affects the system of underground and surface equipment of wells, oil and water treatment plants, which is huge in terms of metal consumption and affects a wide network of oil pipelines, gas pipelines and water pipelines. Secondly, the corrosion process of all equipment usually occurs in a heterogeneous system, i.e. in the system of two non - mixed liquids: oil - water, gasoline - water, waste water-petroleum products.

Fracture Failure Analysis of C110 Oil Tube in a Western Oil Field

There was an oil pipeline fracture found in the unlock process of Z well in western oilfield.The reason that made the oil tube fracturewassystematically studied usingmacroscopic analysis,physical and chemical property test,scanning electron microscope with an energy dispersive X-ray spectrometer and X-ray diffraction analysis.The results suggested that the requirement of relevant standard for C110 steel grade was satisfied with the chemical component and mechanical property of oil tube.The perforation of oil tube made H2S in the fluid medium enter the oil set of connected rings. In addition, the high-pressure gas left by gas contained certain H2S and O2 so that the tubewould fracture and be invalid under the combined action of sulfide stress corrosion and oxygen corrosion.

Selectivity switch in the aerobic oxygenation of sulfides photocatalysed by visible-light-responsive decavanadate

Selective oxygenation of sulfides to sulfones and sulfoxides was demonstrated by photocatalysis of decavanadate using O2 in methyl ethyl ketone.

Catalytic O2 activation with synthetic models of α-ketoglutarate dependent oxygenases.

An iron complex bearing the facially capping tridentate 1,4,7-triazacyclononane ligand mimics structural and functional features of alpha-ketoglutarate (α-KG) dependent enzymes, and engages in enzyme-like catalytic O2 activation coupled to α-ketoacid decarboxylation, oxygenating sulfides. This system constitutes a rare case of non-enzymatic catalytic O2 activation, cycling between FeII and FeIV(O).

Gold–Telluride–Palladium Mineralization, a New Type of Mineralization in Gabbro-Dolerites of the Pai-Khoi Ridge (Yugor Peninsula, Russia)

Abstract —Data on gabbro-dolerite pyrite–chalcopyrite–pyrrhotite, quartz vein sphalerite–chalcopyrite, and associated early and late gold–telluride–palladium mineralization of the Krutoi ore occurrence (Pai-Khoi Ridge, Yugor Peninsula) are presented. The early (magmatic) gold–telluride–palladium mineralization is represented by minerals of the ternary system Ag–Au–Cu, palladium antimonides and stibiotellurides, and platinum arsenides, and the late (hydrothermal) one, by minerals of the binary systems Au–Ag and Au–Pd as well as mercury, lead, and silver tellurides. Sudburyite and testibiopalladite have been first found in the Krutoi ore occurrence; moreover, testibiopalladite has been first discovered in the Pai-Khoi Ridge. Their chemical compositions and Raman spectra have been examined. The results of sulfide sulfur, oxygen, and carbon isotope studies of calcium-containing minerals of chalcopyrite–quartz veinlets suggest assimilation of the material of the host deposits by the ore-forming mantle fluids. The fluid inclusions in the veinlets are divided into nitrogen–methane and carbon dioxide–nitrogen according to the composition of the gas phase. It has been established that the mineral-forming fluids were poorly saturated with gas. Magnesium and calcium salts were predominant in them. The temperature of the formation of quartz in the chalcopyrite–quartz veinlets is close to 300–490 ºC, and sphalerite–chalcopyrite and associated late gold–telluride–palladium mineralization formed at temperatures not exceeding 260 ºC.

Assembling polydopamine on TiO2 for visible light photocatalytic selective oxidation of sulfides with aerial O2

The selective aerobic oxygenation of organic sulfides under mild conditions represents one of the most important chemical transformations because of a wide variety of applications of sulfoxides. However, this reaction is very challenging to be implemented by conventional semiconductor photocatalysis. Herein, polydopamine (PDA) could be easily assembled onto TiO2 semiconductor to afford visible light absorbing TiO2@PDA with a large π-conjugated system of PDA. Subsequently, TiO2@PDA was used to implement aerobic oxidation reaction in CH3OH, relying on the improved stability of PDA due to a large π-conjugated system. Irradiated by 460 nm blue light LEDs, PDA could efficiently transfer electrons to the conduction band of anatase TiO2 which can activate aerial O2. Subsequently, visible light-promoted selective aerobic oxidation of sulfides into corresponding sulfoxides with the cooperation of 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) on TiO2@PDA have been achieved eventually. This work suggests that the promise of assembling a large π-conjugated system on a semiconductor in establishing visible light photocatalytic selective chemical transformations.

Selective Late‐Stage Oxygenation of Sulfides with Ground‐State Oxygen by Uranyl Photocatalysis

AbstractOxygenation is a fundamental transformation in synthesis. Herein, we describe the selective late‐stage oxygenation of sulfur‐containing complex molecules with ground‐state oxygen under ambient conditions. The high oxidation potential of the active uranyl cation (UO22+) enabled the efficient synthesis of sulfones. The ligand‐to‐metal charge transfer process (LMCT) from O 2p to U 5f within the O=U=O group, which generates a UV center and an oxygen radical, is assumed to be affected by the solvent and additives, and can be tuned to promote selective sulfoxidation. This tunable strategy enabled the batch synthesis of 32 pharmaceuticals and analogues by late‐stage oxygenation in an atom‐ and step‐efficient manner.