Complex formation of copper(II) with 2,6-dimercaptophenol and its derivatives in the presence of aminophenols

Abstract

Spectrophotometric methods have been used to investigate the complex formation of copper with 2,6-dimercaptophenol and its derivatives (2,6-mercapto-4-methylphenol and 2,6-dimercapto- 4-tert -buthylphenol) in the presence of aminophenols. As aminophenols 2-(N,N-dimethylaminomethyl)- 4-methylphenol, 2-(N,N-dimethylaminomethyl)-4-chlorophenol, 2-(N,N-dimethylaminomethyl)- 4-bromophenol, 2,6-bis(N,N-dimethylaminomethyl)-4-methylphenol, 2,6-bis(N,N-dimethylaminomethyl)- 4-chlorophenol and 2,6-bis(N,N-dimethylaminomethyl)-4-bromophenol were used. It was established that a mixed ligand complex was formed in a weak acidic medium (pHop = 4.7 ÷ 7.4). The maximum of light absorption was observed at λ = 470 ÷ 485 nm. Molar coefficient of light absorption was ε = (3.58÷4.05)·104 L·mol−1·cm−1. On the basis of the results, a photometric method for determination of copper in steel for use in different trade-marks and in food preparation has been proposed. This method is characterized by good reproduction (relative standard deviation does not exceed 0,05) and low limit of quantitation. Refs 24. Figs 3. Tables 7.