124 tcb

124-TCB (Sigma-Aldrich, Darmstadt, Germany, ≥99%) was used as the target pollutant. The ferrioxalate solution, the catalyst of the process, was prepared using potassium oxalate monohydrate (Sigma-Aldrich, 99.50%) and iron (III) sulphate hydrate (Sigma-Aldrich, 97%). Hydrogen peroxide (35 wt.%), titanium oxysulfate (used for the quantification of Hydrogen peroxide), sodium carbonate, sodium bicarbonate, sulfuric acid, oxalic acid, acetone (used for Ionic Chromatography analysis), 1,10-phenanthroline, sodium acetate (used in the measurement of iron in solution), n-hexane, tetrachloroethane, butyl cyclohexyl (used in COC determination by GC), NaOH (for pH adjustment), catalase, sodium bicarbonate, and sodium chloride were all purchased from Sigma-Aldrich. The bacteria Vibrio fischeri (Microtox^® Acute Reagent, Azur Environmental, Carlsbad, CA, USA) was supplied by I.O. Analytical. All the stock solutions and their dilutions were prepared with high-purity water from a Millipore Direct-Q system (Millipore Corporation, Burlington, MA, USA) (resistivity >18 MΩ cm at 25 °C).

The following chemicals were used for π–π complexation. $\pi$ electron acceptors were 1,3-dinitrobenzene (1,3-DNB, 97%, Sigma-Aldrich); nitrobenzene (NB, 99%, Acros); 1,3-bis(trifluoromethyl)benzene (1,3-BTFMB, 98%, Sigma-Aldrich); 1,2,4-trichlorobenzene (1,2,4-TCB, 99%, Sigma-Aldrich); 1,2-dichlorobenzene (1,2-DCB, 98.6%, Sigma-Aldrich); terephthalaldehyde (TA, 99%, Sigma-Aldrich); pyridine (Py, 99% Sigma-Aldrich) $\pi$ electron donor was mesitylene (MSTL, 97%, JT Baker). Structures for all acceptors and donor are shown in Fig. 1. The solvent was cyclohexane (99%, Acrose).Fig. 1.

The structures of seven aromatic molecules (acceptors) used to interact with MSTL