THERMALLY GUIDED DEHYDRATION OF BINUCLEAR [Ni2(en)2(H2O)6(pyr)]·4H2O COMPLEX: A FURTHER INSIGHT
Thermally prompted dehydration of binuclear [Ni2(en)2(H2O)6(pyr)]·4H2O complex occurs within a 326 K to 410 K temperature region, presenting an asymmetrical DSC peak. The process is endothermal and results in the loss of 10 molecules of water accounting for 26.8% of the total mass of the sample. Values of the apparent activation energy of 71 kJ/mol and 93 kJ/mol were determined by using Kissinger's and the isoconversional KAS approach, respectively. The probable reaction mechanism was determined by Dollimore's analysis. Deconvolution of the experimental DSC peak on different heating rates shows that the mechanism of dehydration changes with the change in the heating regime. Using the linear compensation effect, values of invariant activation energy of 61 kJ/mol as well as of Arrhenius pre-exponential factor of 6·107 min-1 were determined.