Termodynamic Study of the Interaction Between Some Recently Synthesized Benzo-Substituted Macrocyclic Diamides with Some Pyridinium Ion Derivatives in Acetonitrile Solution
The formation of pyridinium, 2-methyl pyridinium, 2,4-dimethyl pyridinium and 2,4,6- trimethyl pyridinium complexes with the some recently synthesized benzo-substituted macrocyclic diamides was investigated conductometrically in acetonitrile solution at various temperatures. The formation constants of the resulting 1:1 complexes were determined from the computer fitting of the molar conductance-mole ratio data. In all cases studied, the stability of complexes decreases in the order Py+ > 2m-Py+ > 2,4dim-Py+ > 2,4,6trim-Py+. The enthalpy and entropy of complexation reaction were determined from the temperature dependence of the formation constants. In all cases, the complexes were enthalpy stabilized but entropy destabilized.