Sulfmyoglobin derived from deuterohemin reconstituted protein. 1. Structure of the initial complex based on the mechanism of formation of subsequent reaction products

1993 ◽  
Vol 115 (15) ◽  
pp. 6513-6521 ◽  
Author(s):  
Maureen A. Scharberg ◽  
Gerd N. La Mar
Keyword(s):  
Reaction Products ◽  
Mechanism Of Formation ◽  
Subsequent Reaction ◽  
Reconstituted Protein

scholarly journals Multi Component Reactions under Increased Pressure: On the Mechanism of Formation of Pyridazino[5,4,3-de][1,6]naphthyridine Derivatives from Reaction of Malononitrile, Aldehyde and 2-Oxoglyoxalarylhydrazones in Q-Tubes

2017 ◽  
Author(s):  
Majdah A. AL-Johani ◽  
Khadijah M. Al-Zaydi ◽  
Sameera M. Mousally ◽  
Norah F. Alqahtani ◽  
Mohamed H. Elnagdi
Keyword(s):  
Crystal Structure ◽  
Reaction Pathway ◽  
Aromatic Aldehydes ◽  
Reaction Products ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Alternate Pathway ◽  
Considerable Research ◽  
Increased Pressure ◽  
Chemical Evidence

The considerable biological and medicinal activities of pyridazines has stimulated considerable research on efficient syntheses of these derivatives. In the last decade, microwave irradiation has generally been used for the energy source. As demonstrated in recent studies, pressure reactor “Q-tubes” may be used to accelerate several of these reactions in a more optimal and safer manner (compared to microwaves). In these studies there has been postulated a pathway for the formation of pyridazino[5,4,3-de][1,6]naphthyridine derivatives . In this paper we consider this pathway, and an alternate pathway, for several reactions. Contrary to the suggestion in these studies the pathway in which initial dimerization of malononitrile was postulated could be excluded based on chemical evidence. The reactions performed were the reaction of arylhydrazonals 1a,b with benzylidinemalononitrile which afforded in Q-tube the 3-acyl-4-aryl-1-phenyl-6-amino-1,4-dihydropyridazines, and the reaction of arylhydrazonals 1a,b, malononitrile 9 and aromatic aldehydes 10a-g in Q-tubes which afforded the tricyclic systems 12a-n whose structure could be established by X-ray crystal structure determination. In conclusion, we have added to the work of the recent studies by excluding a reaction pathway for one of their reaction products.

Mg-K-Fe fluid producing mineral reactions, metasomatism and microfabric development during formation of nodular sillimanite-gneiss in the middle crust

2021 ◽  
Author(s):  
Ane K. Engvik ◽  
Claudia A. Trepmann ◽  
Håkon Austrheim
Keyword(s):  
Stress Condition ◽  
White Mica ◽  
Ore Deposits ◽  
Preferred Orientation ◽  
Reaction Products ◽  
Subsequent Reaction ◽  
Crystallographic Preferred Orientation ◽  
Mineral Reaction ◽  
Metasomatic Fluid ◽  
Mineral Replacement

<p>The Proterozoic gneisses of the Bamble lithotectonic domain (south Norway) underwent intense scapolitisation caused by K- and Mg-rich fluids and extensive albitisation with formation of numerous ore deposits.</p><p>By detailed studies of mineral reaction fabrics we document release of the chemical active Mg, K and Fe-components forming the metasomatic fluid: Breakdown of biotite to muscovite releases K, Mg, Fe, Si and H<sub>2</sub>O. As reaction products tiny Fe-oxide needles are present in the transforming rock. H<sub>2</sub>O is reacting with K-feldspar to produce additional amounts of white mica and quartz. During a subsequent reaction muscovite is replaced to sillimanite again releasing quartz and a K-rich fluid. The reactions form the peculiar sillimanite-nodular quartzite, but also well-foliated sillimanite-mica gneiss.</p><p>Optical and EBSD microfabric studies reveal a shape preferred orientation for quartz, but despite of a pronounced foliation, quartz does not show a crystallographic preferred orientation. A crystallographic preferred orientation is present for mica and sillimanite. Coarse micas show sutured boundaries to quartz, implying low nucleation rates, no crystallographic or surface-energy control during growth and no obvious crystallographic relationship to quartz.</p><p>Our study illustrates the transformation of a quartzofeldspatic lithology into sillimanite-bearing quartzite. The mineral replacement and deformation show ongoing metamorphic reactions during deformation. The microfabric data indicates reaction at non-isostatic stress condition. The deduced mineral replacement reactions document a source of K-, Mg- and Fe-rich metasomatic fluids necessary to cause the pervasive scapolitisation and Fe-deposition in the area. The mineral reactions and deformation produce rocks with a new mineralogy and structure; an increased understanding of these processes is important for the modelling of crustal building and geological history.</p>

scholarly journals Thermal Decomposition and Thermal Reaction Process of PTFE/Al/MnO2 Fluorinated Thermite

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2451 ◽  
Author(s):  
Jun Zhang ◽  
Junyi Huang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Zhongshen Yu ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Control Systems ◽  
Thermal Reaction ◽  
Reaction Process ◽  
Reaction Products ◽  
Subsequent Reaction ◽  
Comparison Results ◽  
Different Temperatures ◽  
Xrd Phase Analysis ◽  
Two Stages

To better understand the thermal decomposition and reaction process of a fluorine-containing powdery thermite, PTFE/Al/MnO2, reactions at different temperatures were investigated by the TG/DSC-MS technique. The corresponding reaction products were characterized with XRD phase analysis. Another three thermite materials, i.e., PTFE/Al, Al/MnO2, and PTFE/MnO2, were also prepared for comparison. Results showed that PTFE behaved as both oxidizer and reducer in PTFE/Al/MnO2 fluorinated thermite. The thermal decomposition and reaction process of as-fabricated ternary thermite could be divided into two stages—the mutual reaction between each of PTFE, Al, and MnO2 and the subsequent reaction produced between Al and Mn2O3/Mn3O4/MnF2. Compared with the three control systems, the specially designed ternary system possessed a shorter reaction time, a faster energy release rate, and a better heat release performance.

THE REACTION OF t-BUTYL ALCOHOL VAPOR WITH Hg 6(3P1) ATOMS

1963 ◽  
Vol 41 (11) ◽  
pp. 2849-2860 ◽  
Author(s):  
Arthur R. Knight ◽  
Harry E. Gunning
Keyword(s):  
Nitric Oxide ◽  
Butyl Alcohol ◽  
Continuous Illumination ◽  
Quantum Yields ◽  
Static System ◽  
Reaction Products ◽  
Subsequent Reaction ◽  
Alcohol Vapor ◽  
Intermittent Illumination ◽  
In Parenthesis

The nature of the decomposition of t-butyl alcohol vapor, photosensitized by Hg 6(3P1) atoms in a static system at room temperature, has been examined under a variety of conditions of continuous and intermittent illumination. The inhibiting effect of nitric oxide has also been studied, as well as the influence of added inert gas.In the decomposition of pure substrate, the reaction products, with the initial quantum yields, Φ°, under continuous illumination in parenthesis, were: H2 (0.045), Me2CO (0.090), CO (0), CH4 (0.015), C2H6 (0.030) together with lesser amounts of C3H8, Me3CH, Me3CMe, and Me3COMe. On addition of nitric oxide, Me3CONO, Me2CO, N2O, N2, H2O, and trace quantities of H2 and CO were the only products observed.The reaction[Formula: see text]is proposed as the primary process in the decomposition and kinetic evidence is presented that the initially formed t-butoxy radicals possess excess energy and that their principal subsequent reaction is unimolecular cleavage into acetone and methyl. The results furthermore indicate that the substrate itself is quite inert to abstractive attack by the primary radicals.

scholarly journals NUCLEOPHILIC SUBSTITUTION OF NITRO GROUP IN 1-METHYL- 5-NITRO-1,2,4-TRIAZOLE BY DIAMINOGLYOXIME

2021 ◽  
pp. 95-100
Author(s):  
И.А. Крупнова ◽  
Г.Т. Суханов ◽  
К.К. Босов ◽  
А.Г. Суханова ◽  
Ю.В. Филиппова ◽  
...  
Keyword(s):  
Nitro Group ◽  
Single Molecule ◽  
Bioactive Compound ◽  
Reaction Products ◽  
Subsequent Reaction ◽  
Web Resource ◽  
Competitive Reactions ◽  
Pharmaceutical Substances ◽  
Pass Online ◽  
Online Web

Изучен процесс взаимодействия 1-метил-5-нитро-1,2,4-триазола с многоцентровым бифункциональным О-нуклеофилом – диаминоглиоксимом. Показано, что исходный субстрат вступает в реакцию SNipso-замещения нитрогруппы с гидроксильными группами О-нуклеофила с образованием биологически активного соединения, объединяющего в единой молекуле фармакофорные фрагменты различного типа – 1,2,4-триазоловые гетероциклы и NH2-группы. Процесс сопровождается конкурентными реакциями образования триазолона и продукта его дальнейшего взаимодействия с исходным субстратом. С помощью веб-ресурса PASS Online осуществлен компьютерный скрининг, показано, что исходный субстрат и продукты реакции могут выступать потенциальными фармацевтическими субстанциями. The reaction between 1-methyl-5-nitro-1,2,4-triazome and a concerted bifunctional О-nucleophile – diaminoglyoxime was explored herein. The starting substrate was shown to engage into the SNipso-substitution of the nitro group by the О-nucleophile hydroxyls to furnish a bioactive compound whose single molecule combines different-type pharmacophoric moieties – 1,2,4-triazole heterocycles and NH2groups. The process came amid competitive reactions to form triazolone and a product from its subsequent reaction with the starting substrate. The PASS Online web-resource was used to perform computer-aided screening, demonstrating that the starting substrate and the reaction products can serve as potential pharmaceutical substances.

Thermodynamic Considerations in Thin-Film Metallizations

1985 ◽  
Vol 47 ◽  
Author(s):  
Robert Beyers
Keyword(s):  
Integrated Circuits ◽  
Ternary Phase ◽  
Elevated Temperatures ◽  
Reaction Products ◽  
New Materials ◽  
Subsequent Reaction ◽  
Ternary Phase Diagrams ◽  
Circuit Fabrication ◽  
The Stability ◽  
Selection Of

ABSTRACTThe drive to produce smaller devices in integrated circuits is wellknown. Concurrent with this drive is the need to incorporate new materials, such as silicides, as interconnects, diffusion barriers, and contacts. During circuit fabrication, these materials are in contact with other solids and gases at elevated temperatures. Consequently, reactions may occur which degrade the materials present. Since the reactions of interest typically involve three elements distributed in several phases, ternary phase diagrams are required to predict the occurrence of a reaction and the subsequent reaction products, or, conversely, the stability of the phases present. Hence, ternary diagrams can provide important guidance in the selection of optimal materials and the design of reliable processing schedules.

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