A Conductometric study of complexation reaction between dibenzyl-14-crown-4, with ZrO2+ in some binary mixed nonaqueous solvents

Abstract

In Some binary methanol mixtures, (MeOH), 1,2 dichloroethane (DCE), acetonitrile (AN), and tetrahydrofuran (THF), with dimethylformamide (DMF) at different temperatures using the conductometric process, the reaction of macrocyclic ligand to complexation, dibenzyl-14-crown-4 (DB14C4) with ZrO2+ cation was examined. The conductance data show that in all solvent systems, the stoichiometry of the complex formed between (DB14C4) and ZrO2+ cation is 1:1 (M:L). The stability order of (DB 14C4.ZrO)2+complex in pure non-aqueous solvents was found to be: [AN], [DCE], [MeOH], [THF], [DMF]. A non-linear behaviour was observed improvements in log Kf of (DB14C4.ZrO)2+ complex or Binary mixed solvent composition, It Was clarified as to the Interactions with solvents and even solvents in terms of the hetero-selective solving of the ecosystem affected by complexation response. The obtained results show that the stability of (DB14C4.ZrO)2+ complex is sensitive to the composition of the mixed solvent. The values of thermodynamic parameters ΔH°cand ΔS°c) for the formation of (DB14C4.ZrO)2+complex using van’t Hoff maps, the stability constant was obtained from temperature dependence. The results show that in most cases, the (DB 14C4.ZrO)2+complex is enthalpy destabilized but entropy balanced and the values and signs of thermodynamic parameters are often These are decided by nature and composition of the mixed solvents.