Chelate formation and stability analysis of cobalt, nickel and copper with lomatiol

The pH-metric studies on the interaction of divalent metal cations, Co (II), Ni (II) and Cu (II) with lomatiol have been performed under the thermodynamic conditions achievable at constant ionic strength and infinite dilution in which a mole of divalent metal, combined with 02 mol of lomatiol. Lomatiol being bidentate could replace two water molecules at a time. The values of stepwise formation constants showed no conspicuous difference at 25 °C and 35 °C, and the complexes, registered a decrease in their stability values suggesting the low temperature as a favorable condition under which the chelation of metal with lomatiol is feasible. The reaction takes place without the use of any specific catalyst although under alkaline conditions. The reactions of lomatiol with metal cations in solution had been adjudged as the spontaneous reaction on account of the negative ΔG value in all the metal lomatiol systems. Also the study showed the positive experimental values of entropy changes in all the systems and negative value of free energy. The continuous fall in the values of the stepwise formation constants (k1 > k2 > k3) in the divalent metal-lomatiol system has been assigned to the statistical factor.