Croatica Chemica Acta, Vol. 98 No. 3, 2025.
Original scientific paper
https://doi.org/10.5562/cca4204
A Novel Tris(Chromium(III))–4-Nitrocatechol Complex Extracted via an Eco-Friendly Ionic Liquid-Assisted Method
Petya Vassileva Racheva
; Department of Chemical Sciences, Medical University of Plovdiv, 120 Buxton Brothers St., Plovdiv 4004, Bulgaria
Antoaneta Dimitrova Saravanska
; Department of Chemical Sciences, Medical University of Plovdiv, 120 Buxton Brothers St., Plovdiv 4004, Bulgaria
Denitsa Dimitrova Kiradzhiyska
; Department of Chemical Sciences, Medical University of Plovdiv, 120 Buxton Brothers St., Plovdiv 4004, Bulgaria
Vassil Borisov Delchev
; Department of Physical Chemistry, Faculty of Chemistry, Plovdiv University “Paisii Hilendarski”, 24 Tsar Assen Street, Plovdiv 4000, Bulgaria
Kiril Blazhev Gavazov
orcid.org/0000-0002-1360-8977
; Department of Chemical Sciences, Medical University of Plovdiv, 120 Buxton Brothers St., Plovdiv 4004, Bulgaria
*
* Corresponding author.
Abstract
A novel mixed micelle-mediated cloud point extraction (MM CPE) system for Cr(III) was investigated spectrophotometrically. In this system, 4 nitrocatechol (4NC) acts as the chelating agent, while the ionic liquid Aliquat 336 (A336) functions both as a cationic ion association reagent and as a co surfactant that forms mixed micelles with Triton X 114. The extracted complex was identified as (A336+)3[Cr(4NC)3]. The structure of its anionic part [Cr(4NC)3]3– was further analyzed through B3LYP/6 311G theoretical optimizations and by comparing calculated and experimental UV/Vis spectra. The ternary complex exhibits a maximum absorbance at 475 nm with a molar absorption coefficient of 2.4 × 105 M–1 cm–1 (tenfold enrichment). The calibration curve demonstrated linearity over a Cr(III) concentration range of 40–420 ng mL–1, with a detection limit of 12 ng mL–1. The logarithmic conditional extraction constant (Kex) was determined to be 12.0 ± 0.1, indicating an efficient extraction process.
Keywords
chromium(III); cloud point extraction; spectrophotometry; 4-nitrobenzene-1,2-diol; Aliquat336; TD DFT calculations
Hrčak ID:
342823
URI
Publication date:
10.7.2025.
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