Next Article in Journal
A Modular Synthetic Approach to Isosteric Sulfonic Acid Analogues of the Anticoagulant Pentasaccharide Idraparinux
Previous Article in Journal
Simultaneous Determination of Coumarin and Its Derivatives in Tobacco Products by Liquid Chromatography-Tandem Mass Spectrometry
Previous Article in Special Issue
Towards a Rational Design of a Continuous-Flow Method for the Acetalization of Crude Glycerol: Scope and Limitations of Commercial Amberlyst 36 and AlF3·3H2O as Model Catalysts
Article Menu
Issue 11 (November) cover image

Export Article

Open AccessArticle
Molecules 2016, 21(11), 1514; doi:10.3390/molecules21111514

Kinetic Spectrophotometric Method for the 1,4-Diionic Organophosphorus Formation in the Presence of Meldrum′s Acid: Stopped-Flow Approach

Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98135-674, Zahedan 9816744599, Iran
*
Author to whom correspondence should be addressed.
Academic Editors: Kerry Gilmore and Derek J. McPhee
Received: 6 August 2016 / Revised: 1 November 2016 / Accepted: 2 November 2016 / Published: 11 November 2016
(This article belongs to the Special Issue Recent Advances in Flow Chemistry)
View Full-Text   |   Download PDF [2920 KB, uploaded 11 November 2016]   |  

Abstract

The kinetics of the reaction between triphenylphosphine (TPP) and dimethyl acetylenedicarboxylate (DMAD) in the presence of Meldrum’s acid (MA) for the generation of the 1,4-diionic organophosphorus compound has been investigated using the stopped-flow and UV-VIS spectrophotometry techniques. The first step of the reaction between TPP and DMAD for the generation of (I1) in ethanol was followed by the stopped-flow apparatus. This step was recognized as a fast step. The reaction between the intermediate (I1) and MA showed first-order kinetics, and it was followed by the UV-VIS spectrophotometry technique. The activation parameters for the slow step of the proposed mechanism were determined using two linearized forms of the Eyring equation. From the temperature, concentration and solvent studies, the activation energy (Ea = 20.16 kJ·mol−1) and the related activation parameters (ΔG = 71.17 ± 0.015 kJ·mol−1, ΔS = −185.49 ± 0.026 J·mol−1 and ΔH =17.72 ± 0.007 kJ·mol−1) were calculated. The experimental data indicated that the reaction was zero-order in MA and second-order overall. The proposed mechanism was confirmed with the observed kinetic data obtained from the UV-VIS and stopped-flow techniques. View Full-Text
Keywords: kinetics; zwitterionic intermediate; stopped-flow; mechanism kinetics; zwitterionic intermediate; stopped-flow; mechanism
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Ghodsi, F.; Habibi-Khorassani, S.M.; Shahraki, M. Kinetic Spectrophotometric Method for the 1,4-Diionic Organophosphorus Formation in the Presence of Meldrum′s Acid: Stopped-Flow Approach. Molecules 2016, 21, 1514.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top