scholarly journals Photochemical Dechlorination of 2,3,7,8-, 1,3,6,8-, and 1,2,3,4-Tetrachlorodibenzo-p-dioxins as Studied by the Frontier-Electron Reactivity Indexes.

1993 ◽  
Vol 41 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Masakazu MAKINO ◽  
Shunsuke KAZAMA ◽  
Mamoru KAMIYA
Keyword(s):  
Reactivity Indexes

scholarly journals Combustion and gasification characteristics of low-temperature pyrolytic semi-coke prepared through atmosphere rich in CH4 and H2

2021 ◽  
Vol 10 (1) ◽  
pp. 189-200
Author(s):  
Yuan She ◽  
Chong Zou ◽  
Shiwei Liu ◽  
Keng Wu ◽  
Hao Wu ◽  
...  
Keyword(s):  
Functional Groups ◽  
Chemical Structure ◽  
Nitrogen Adsorption ◽  
Inhibitory Effect ◽  
X Ray ◽  
Coke Reactivity ◽  
Reducing Gas ◽  
Reactivity Indexes ◽  
Infrared Spectrometer ◽  
Reducing Gases

Abstract Thermoanalysis was used in this research to produce a comparative study on the combustion and gasification characteristics of semi-coke prepared under pyrolytic atmospheres rich in CH4 and H2 at different proportions. Distinctions of different semi-coke in terms of carbon chemical structure, functional groups, and micropore structure were examined. The results indicated that adding some reducing gases during pyrolysis could inhibit semi-coke reactivity, the inhibitory effect of the composite gas of H2 and CH4 was the most observable, and the effect of H2 was higher than that of CH4; moreover, increasing the proportion of reducing gas increased its inhibitory effect. X-ray diffractometer and Fourier-transform infrared spectrometer results indicated that adding reducing gases in the atmosphere elevated the disordering degree of carbon microcrystalline structures, boosted the removal of hydroxyl- and oxygen-containing functional groups, decreased the unsaturated side chains, and improved condensation degree of macromolecular networks. The nitrogen adsorption experiment revealed that the types of pore structure of semi-coke are mainly micropore and mesopore, and the influence of pyrolytic atmosphere on micropores was not of strong regularity but could inhibit mesopore development. Aromatic lamellar stack height of semi-coke, specific surface area of mesopore, and pore volume had a favorable linear correlation with semi-coke reactivity indexes.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

A theoretical study on the regioselectivity of 1,3-dipolar cycloadditions using DFT-based reactivity indexes

Tetrahedron ◽  
2004 ◽  
Vol 60 (50) ◽  
pp. 11503-11509 ◽  
Author(s):  
M.José Aurell ◽  
Luis R. Domingo ◽  
Patricia Pérez ◽  
Renato Contreras
Keyword(s):  
Theoretical Study ◽  
Dipolar Cycloadditions ◽  
Reactivity Indexes

scholarly journals Relations among several nuclear and electronic density functional reactivity indexes

2003 ◽  
Vol 119 (18) ◽  
pp. 9393-9400 ◽  
Author(s):  
Miquel Torrent-Sucarrat ◽  
Josep M. Luis ◽  
Miquel Duran ◽  
Alejandro Toro-Labbé ◽  
Miquel Solà
Keyword(s):  
Density Functional ◽  
Electronic Density ◽  
Reactivity Indexes

Reactivity indexes of antioxidant molecules from Rosmarinus officinalis

2017 ◽  
Vol 29 (3) ◽  
pp. 741-751 ◽  
Author(s):  
D. Alejandro Hernandez ◽  
Francisco J. Tenorio
Keyword(s):  
Rosmarinus Officinalis ◽  
Reactivity Indexes

scholarly journals The effect of porosity on the reactivity of calcium sorbents

Mineralogia ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 37-45
Author(s):  
Michał Wichliński ◽  
Rafał Kobyłecki
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Total Porosity ◽  
Classical Procedure ◽  
Reactivity Indexes ◽  
Capacity Index

Abstract The current work presents the results of seven sorbent samples investigated with respect to SO2 capture. The sorbents’ reactivity and capacity indexes were determined, and the tests were carried out in accordance with the ‘classical’ procedure for limestone sorbents. The reactivity indexes (RIs) of the tested samples were in the range of 2.57 and 3.55 (mol Ca)/(mol S), while the absolute sorption coefficients as determined by the capacity index (CI) varied between 87.9 and 120.6 (g S)/(kg of sorbent). Porosimetric analysis was also carried out and the specific surface area of the samples was found to be between 0.2 and 1.7 m2/g. The number of micro-, meso- and macro-pores in individual samples was determined from the corresponding pore size distribution histograms, and the values of sorbent RIs and CIs were correlated with the samples’ total porosity and specific surface.

scholarly journals 1-(2-Chlorobenzyloxy)-3-[1,2,3]triazol-1-yl-propan-2-ol Derivatives: Synthesis, Characterization, and DFT-Based Descriptors Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Eloisa Román-Maldonado ◽  
Horacio Reyes ◽  
Miguel A. Sanchez-Carmona ◽  
Nelly González-Rivas ◽  
Erick Cuevas-Yañez
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Functional Theory ◽  
Local Reactivity ◽  
Reactivity Indexes ◽  
Global And Local

A novel series of 1-(2-chlorobenzyloxy)-3-[1,2,3]triazol-1-yl-propan-2-ol derivatives was designed and synthesized using copper catalyzed alkyne-azide cycloaddition in the key step. Theoretical investigation of molecular and electronic properties by means of global and local reactivity indexes of the synthetized compounds was carried out, using DFT (Density Functional Theory) at PBEPBE/6-31++G⁎⁎level.

AN ANALYSIS OF THE REGIOSELECTIVITY IN HETERO DIELS–ALDER REACTIONS USING DFT-BASED REACTIVITY INDEXES

2006 ◽  
Vol 05 (02) ◽  
pp. 197-206 ◽  
Author(s):  
H. CHEMOURI ◽  
S. M. MEKELLECHE
Keyword(s):  
Diels Alder ◽  
Maximum Hardness ◽  
Activation Barriers ◽  
Reactivity Indexes ◽  
Maximum Hardness Principle ◽  
Theoretical Results

The regioselectivity of hetero Diels–Alder reactions (HDA) of 2-azabutadiene with aldehydes has been elucidated by means of Gazquez–Mendez rules, which are based on the calculation of local softnesses of the four terminal atoms involved in cyclization. The theoretical results obtained with the B3LYP/6-31G(d) method confirm the regioselectivities observed experimentally for all substituents ( R = H , CH 3, CN ) present in the aldehyde reactant. The regioselectivities of these HDA reactions have been confirmed by the calculation of the activation barriers corresponding to the two cyclization modes, and also by the application of the Houk rule and the maximum hardness principle.

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