Determination of Gluconate Binding Properties on Magnetite Surface and Investigation of Carboxymethylation and Hydrazination Mechanisms of the Gluconated Magnetite Surface: A Computational Study

• Main Authors: Işılay ÖZTÜRK, Şenay ŞANLIER, Armağan KINAL
• Format: Article
• Language: English
• Published: Turkish Chemical Society 2020-02-01
• Series: Journal of the Turkish Chemical Society, Section A: Chemistry
• Subjects: magnetite nanoparticles; binding properties; dft; carboxymethylation; hydrazination; gluconate
• Online Access: https://dergipark.org.tr/en/pub/jotcsa/issue/49279/615671

In the present study, the probable binding structure of a gluconate molecule with magnetite, (Fe3O4) nanoparticles, as well as, carboxymethylation and hydrazination mechanisms of the gluconate bound to the iron oxide surface have been computationally investigated by the DFT-B3LYP method. The B3LYP/LanL2DZ calculations together with experimental IR data available revealed that the probable binding structure of gluconate is bidentate bridged binding to the magnetite surface. The carboxymethylation and hydrazination mechanisms of gluconate were calculated at B3LYP/6-31+G(d,p) level of theory. The results indicate that the reaction between gluconate and chloroacetate in aqueous medium has one step mechanism passing through a low activation barrier (12.3 kcal/mol) with a reaction enthalpy of –42.8 kcal/mol. In addition, hydrazone bond formation reaction of the gluconate bound to the iron oxide surface has a highly-exothermic two-step-mechanism with barriers of 7.1 and 2.4 kcal/mol, respectively, in water. The activation barrier of the overall reaction is accepted as the barrier of the first step since the barrier of this step is greater than that of the second one. Consequently, it can be predicted that both carboxymethylation and hydrazination reactions should be spontaneous under moderate conditions.