Please use this identifier to cite or link to this item:
http://nopr.niscair.res.in/handle/123456789/981
Title: | Studies on hydrolysis of methyl parathion with Zr(IV), Hf(IV) and Cu(II) catalysts in acidic aqueous solutions |
Authors: | Algiwale, Tushar Amar Shinde, C P Purnanand |
Issue Date: | Feb-2007 |
Publisher: | CSIR |
IPC Code: | Int. Cl.⁸ C07B41/00 |
Abstract: | Hydrolysis of O,O-dimethyl O-p-nitrophenyl phosphoro-thionate (Methyl Parathion) has been studied in acidic medium with catalysts such as Zr⁴⁺, Hf⁴⁺ and Cu²⁺ cations. In the case of Zr⁴⁺ and Hf⁴⁺ cations, the rate maxima were observed around pH 2.0. Since the metal bound water molecules (M-OH₂) of octameric metal-complex are known to exist in equilibrium with metal-hydroxide ion (M-OH⁻), OH⁻ nucleophiles are abundantly available from these cations even in acidic aqueous solutions. Therefore, an interaction of sulphur of P=S group with metal ion and an intramolecular nucleophilic attack of metal bound OH⁻ at phosphorus atom results in P-O bond cleavage to liberate p-nitrophenol. The 3.2×10⁴ fold rate enhancement with respect to uncatalyzed hydrolysis at pH 6.0 for Cu²⁺ catalysis, has been attributed to high reactivity of hexa-aquo copper complex (i.e., [Cu(H₂O)₆]²⁺), which is known to predominate at around pH 6.0. |
Page(s): | 269-272 |
URI: | http://hdl.handle.net/123456789/981 |
ISSN: | 0376-4710 |
Appears in Collections: | IJC-A Vol.46A(02) [February 2007] |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
IJCA 46A(2) (2007) 269-272.pdf | 138.67 kB | Adobe PDF | View/Open |
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.