Quaternary Heteroarenium Aldoximes as Catalysts for Cleavage of Phosphate Esters

[img]PDF - Authorized users only
Language: English
120Kb
Title:Quaternary Heteroarenium Aldoximes as Catalysts for Cleavage of Phosphate Esters
Creators:
Hampl, František
Mazáč, Jiří
Liška, František
Šrogl, Jiří
Kábrt, Lubomír
Suchánek, Miloslav
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 60, 5, pp. 883-893

Abstract

<p>1-Methyl- (<i>Ia</i> - <i>Id</i>) and 1-dodecyl-2-, 3- and 4-hydroxyiminomethylpyridinium salts (<i>Ie</i> - <i>Ih</i>), as well as 1-methyl- (<i>IIa</i>) and 1-dodecyl-3-hydroxyiminomethylpyridazinium salts (<i>IIb</i>, <i>IIc</i>), were synthesized as catalysts for hydrolytic cleavage of organophosphates. The activities of the prepared catalysts were evaluated by measuring rate constants of hydrolysis of 4-nitrophenyl diphenyl phosphate (PNPDPP) under conditions of a pseudo-first-order reaction. The observed reactivity of pyridinium aldoximes <i>Ia</i> - <i>Ih</i> towards PNPDPP in neutral or slightly basic aqueous solutions (pH 7.2 and 7.8) depends on the acidity of the hydroxyimino group. The cleavage of PNPDPP is strongly accelerated in solutions of 1-dodecylhydroxyiminomethylpyridinium salts <i>Ie</i> - <i>Ih</i> above their critical micellar concentration (CMC). Considerable effect on the velocity of PNPDPP cleavage was observed when quaternary pyridinium aldoximes <i>Ie</i> - <i>Ih</i> were comicellized with inert cationic tenside hexadecyltrimethylammonium bromide (CTAB). 1-Dodecyl-3-hydroxyiminomethylpyridazinium salts <i>IIb</i> and <i>IIc</i> were unstable in aqueous solutions under the above-mentioned conditions.

Title:Quaternary Heteroarenium Aldoximes as Catalysts for Cleavage of Phosphate Esters
Creators:
Hampl, František
Mazáč, Jiří
Liška, František
Šrogl, Jiří
Kábrt, Lubomír
Suchánek, Miloslav
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:60
Number:5
Page Range:pp. 883-893
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19950883UNSPECIFIED
ID Code:779
Item Type:Article
Deposited On:06 Feb 2009 17:03
Last Modified:06 Feb 2009 16:03

Citation

Hampl, František; Mazáč, Jiří; Liška, František; Šrogl, Jiří; Kábrt, Lubomír; Suchánek, Miloslav (1995) Quaternary Heteroarenium Aldoximes as Catalysts for Cleavage of Phosphate Esters. Collection of Czechoslovak Chemical Communications, 60 (5). pp. 883-893. ISSN 0010-0765

Repository Staff Only: item control page