Tungsten(VI) Complexes with 2-Hydroxy-5-chlorothiophenol in the Presence of Aminophenols and Their Application

In the present paper, we report results from liquid–liquid extraction-spectrophotometric studies on two different systems, each containing W(VI), a 2-hydroxy-5-chlorothiophenol (H2L), and aminophenols (AP1,2), namely, 2(N,N-dimethylaminomethyl)-4-chlorphenol (АP1) and 2(N,N-dimethylaminomethyl)-4-bromphenol (AP2)}. Extraction of mixed-ligand complexes is maximal at pH 4.1–5.2. The absorption maxima of the mixed-ligand complexes (MLCs) W(V)–L–AP1,2 lie in the range of 476–480 nm. The molar absorption coefficients are (2.3–2.4) × 104. The proposed method were applied to the determination of tungsten in steel and soil samples.