Kinetics of Malachite Green Fading in Water‐ethanol‐1‐propanol Ternary Mixtures

Abstract

The rate constant of malachite green (MG + ) alkaline fading was measured in water-ethanol-1-propanol ternary mixtures. This reaction was studied under pseudo-first-order conditions at 283-303 K. It was observed that the reaction rate constant increases in the presence of different weight percentages of ethanol and 1-propanol. The fundamental rate constants of MG + fading in these solutions were obtained by SESMORTAC model. In each series of experiments, concentration of one alcohol was kept constant and the concentration of the second one was changed. It was observed that at constant concentration of one alcohol and variable concentrations of the second one, with increase in temperature, k 1 values increase and this indicates that presence of ethanol (or 1-propanol) increases dissolution of 1-propanol (or ethanol) in the activated complex formed in these solutions. Also, in each zone, fundamental rate constants of reaction at each certain temperature change as k k k 2 1 1 >> >> -.

Organic additives stabilize RNA aptamer binding of malachite green

“…HPLC investigations display only MG and MGOH as the major reactants and products. The 1:1 conversion of MG peak to MGOH peak combined with the UV profile spectra confirms the conversion of MG to MGOH with no other peaks of interests detected [21,35,36]. No other MG variants (i.e.…”

Kinetics of Fading of Some Triphenylmethane Dyes: Effects of Electric Charge, Substituent, and Aqueous Binary Mixtures of Dimethyl Sulfoxide and 2‐Propanol

“…In continuation of earlier work , we compared effects of different concentrations of 2‐propanol (a protic solvent) and DMSO (an aprotic solvent) in water on the ME 2+ , BG + , FA 2− , and BPB 2− alkaline fading rate. These two organic solvents have a lower dielectric constant than water and according to Hughes–Ingold rules for solvent effects in nucleophilic substitution reactions , formation of the neutral or less charged carbinol base from two charged reactants may be more favorable and formation of the more charged carbinol base from them is not more favorable in higher weight percentages of these solvents and increases or decrease the reaction rate, respectively.…”