Spectroscopic and electrochemical investigation of interactions between metal Cr(VI) and Thiram (Tetramethylthiuram disulfide)

V C Jayawardena,A N Navaratne

doi:10.4038/cjs.v47i2.7518

Abstract

Evidences for the presence of interactions between a widely used fungicide called thiram and Cr(VI) ions have been obtained by an electrochemical and spectroscopic approach. The highest absorbance (894 nm) and the peak current (Cyclic Voltammetry) have been detected when the equimolar-concentrated solutions of thiram and Cr(VI) were mixed in the ratio of 2:1. The interactions in the aforementioned mixture were further confirmed by FTIR studies.

Highlights

Thiram is a ithiocarbamate pesticide, which is mainly used as a fungicide to prevent crop damage in the field and to protect harvested crops from deterioration in storage or transport (Figure 1)
Continuous variation method was carried out using UVVisible spectroscopy
There, appearance of a new peak was noted at 400 nm

Summary

Introduction

Thiram (tetramethylthiuram disulfide) is a ithiocarbamate pesticide, which is mainly used as a fungicide to prevent crop damage in the field and to protect harvested crops from deterioration in storage or transport (Figure 1). Thiram is an animal repellent too, so it protects fruit trees and ornamentals from damage by rabbits, rodents, and deer (Sharma et al, 2003). Thiram has the potential to act as a ligand and to form complexes with metals (Valle et al, 2010). This ability has allowed the commercialization of a Zn enriched analogue of thiram which is known as Ziram (Borg and Tjaelve, 1988). It is known in literature that dithiocarbamates form lipophilic (water insoluble) complexes with di- and trivalent metallic cations by bonding through the sulphur atoms (Thorn and Ludwig, 1962) (Figure 2). The cleavage of S-S bond of Thiram has been evidenced previously by surface-enhanced Raman spectroscopy (Sanchéz-Cortés et al, 1998) and this cleavage leads to two resonance structures (Kang et al, 2002) as in Figure 2C below

Methods

Results

Conclusion