Study on the Chelate Formation and the Ion-association of Anionic Chelate of Molybdenum(VI) with 3,5-Dinitrocatechol and Monotetrazolium Cation

• Main Authors: Kirila Stojnova, Vidka Divarova, Petya Racheva, Kristina Bozhinova, Vanya Lekova
• Format: Article
• Language: English
• Published: Slovenian Chemical Society 2018-03-01
• Series: Acta Chimica Slovenica
• Subjects: molybdenum(VI); chelate formation, ion-associate; extraction equilibria
• Online Access: https://journals.matheo.si/index.php/ACSi/article/view/3860
• ISSN: 1318-0207; 1580-3155

The equilibria of the chelate formation and ion-association in the liquid-liquid extraction system Mo(VI)‒3,5-DNC‒INT‒H2O‒CHCl3 were studied by spectrophotometry. The optimum conditions for the chelate formation and extraction of the ion-associated complex formed between the anionic chelate of Mo(VI)‒3,5-dinitrocatechol (3,5-DNC) and the cation of 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT) were established. The validity of Beer’s law was checked and some analytical characteristics were calculated. The effect of various co-existing ions and reagents on the process of complex formation was investigated. The molar ratio of the components in the ternary ion-associated complex Mo(VI)–3,5-DNC–INT was determined by independent methods. The association process in aqueous phase and the extraction equilibria were investigated and quantitatively characterized. The following key constants of the processes were calculated: association constant, distribution constant, extraction constant and recovery factor. Based on this, a reaction scheme, a general formula and a structure of the complex were suggested.