Kinetics of Formation of Hyperbranched Polyesters Based on 2,2-Bis(methylol)propionic Acid

1996 ◽  
Vol 29 (4) ◽  
pp. 1222-1228 ◽  
Author(s):  
E. Malmström ◽  
A. Hult
2015 ◽  
Vol 19 (12) ◽  
pp. 1251-1255 ◽  
Author(s):  
Yi Gao ◽  
Ji Gang Pan ◽  
Yue Jun Huang ◽  
Shuang Yan Ding ◽  
Meng Liang Wang

Three mono-fluorine substituted porphyrin compouds were synthesized under microwave irradiation. The effects of catalysts and oxidants on the yields of mono-fluorine substituted porphyrins also were investigated. The yields of 5,10,15,20-tetrakis(4-fluorophenyl)porphyrin, 5,10,15,20-tetrakis(3-fluorophenyl)porphyrin, 5,10,15,20-tetrakis(2-fluorophenyl)porphyrin in a use of nitrobenzene in propionic acid were 36%, 30% and 28%, respectively. In addition, the zinc(II) ion incorporation reactions into porphyrins to form the zinc porphyrin complexes have been kinetically investigated in acetic acid.


1979 ◽  
Vol 44 (3) ◽  
pp. 912-917 ◽  
Author(s):  
Vladimír Macháček ◽  
Said A. El-bahai ◽  
Vojeslav Štěrba

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.


1986 ◽  
Vol 51 (12) ◽  
pp. 2786-2797
Author(s):  
František Grambal ◽  
Jan Lasovský

Kinetics of formation of 1,2,4-oxadiazoles from 24 substitution derivatives of O-benzoylbenzamidoxime have been studied in sulphuric acid and aqueous ethanol media. It has been found that this medium requires introduction of the Hammett H0 function instead of the pH scale beginning as low as from 0.1% solutions of mineral acids. Effects of the acid concentration, ionic strength, and temperature on the reaction rate and on the kinetic isotope effect have been followed. From these dependences and from polar effects of substituents it was concluded that along with the cyclization to 1,2,4-oxadiazoles there proceeds hydrolysis to benzamidoxime and benzoic acid. The reaction is thermodynamically controlled by the acid-base equilibrium of the O-benzylated benzamidoximes.


2021 ◽  
Vol 329 ◽  
pp. 115537
Author(s):  
Nazia Iqbal ◽  
S.M. Shakeel Iqubal ◽  
Aejaz Abdullatif Khan ◽  
Tasneem Mohammed ◽  
Ali Mohamed Alshabi ◽  
...  

Polyhedron ◽  
1995 ◽  
Vol 14 (10) ◽  
pp. 1299-1306 ◽  
Author(s):  
Ki-Young Choi ◽  
Dong Won Kim ◽  
Choon Pyo Hong

2021 ◽  
pp. 130612
Author(s):  
Eliara Acipreste Hudson ◽  
Hauster Maximiler Campos de Paula ◽  
Yara Luiza Coelho ◽  
Nícolas Glanzmann ◽  
Adilson David da Silva ◽  
...  

1994 ◽  
Vol 33 (18) ◽  
pp. 4070-4076 ◽  
Author(s):  
Eva Toth ◽  
Erno Brucher ◽  
Istvan Lazar ◽  
Imre Toth

1970 ◽  
Vol 12 (8) ◽  
pp. 1922-1928 ◽  
Author(s):  
Yu.A. Ol'khov ◽  
A.I. Ivanov ◽  
V.B. Lugovoi ◽  
S.M. Baturin ◽  
S.G. Entelis

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