Mechanistic investigations on the oxidation of <Emphasis Type="SmallCaps">l</Emphasis>-valine by diperiodatocuprate(III) in aqueous alkaline medium: a kinetic model期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

按检索

Mechanistic investigations on the oxidation of <Emphasis Type="SmallCaps">l</Emphasis>-valine by diperiodatocuprate(III) in aqueous alkaline medium: a kinetic model

Authors:

Balesh A Deganatti Nagaraj P Shetti Sharanappa T Nandibewoor

Institution:

(1) P.G. Department of Studies in Chemistry, Karnatak University, Dharwad, Karnataka, 580 003, India

Abstract:

The oxidation of l-valine (l-val) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength of 3.0 × 10⁻³ mol dm⁻³ was studied spectrophotometrically at 298 K and follows the rate law;

${\text{Rate}} = - \frac{{{\text{d}}{\text{DPC}}]}}{{{\text{d}}t}} = \frac{{kK_{4}K_{5} K_{6}{\hbox{{\sc{l}}-val}}]{\text{DPC}}]}}{{{\text{OH}}^{ - }]{\text{H}}_{3} {{\text{IO}}_{6}}^{2 - } ] + K_{4}{\text{H}}_{3} {{\text{IO}}_{6}}^{2 - } ] + K_{4} K_{5} + K_{4}K_{5} K_{6} {\hbox{{\sc{l}}-val}}]}}$

where K ₄, K ₅ and K ₆ are the equilibrium constants for the different steps involved in the mechanism, k is the rate constant for the slow step of the reaction. The appearance of l-val] term in both numerator and denominator explains the observed less than unit order in l-val]. Similarly the appearances of H₃IO₆ ²⁻] and OH⁻] in the denominator obey the experimental negative less than unit order in H₃IO₆ ²⁻] and OH⁻], respectively. The oxidation reaction in alkaline medium proceeds via a DPC-l-valine complex, which decomposes slowly in a rate determining step followed by other fast steps to give the products. The main products were identified by spot test and spectroscopic studies.

Keywords:

本文献已被 SpringerLink 等数据库收录！

设为首页 | 免责声明 | 关于勤云 | 加入收藏