Abstract

Karuppannan Parimalagandhi¹, Sundararajan Vairam*

DOI : http://dx.doi.org/10.13005/ojc/300458

Tetrahydrazine lanthanum 2-hydroxy-1-naphthoate [La₂(NA)₃L₄] (where  NA and L indicate C₁₀H₆(2-O)(1-COO) and N₂H₄ respectively) was synthesised and characterised by micro elemental analysis, IR spectroscopy, simultaneous TG-DTA and X-ray diffraction (XRD) analysis. The results indicate that the compound loses  hydrazine molecules in the temperature range 65 - 150 °C and decomposes to La₂O₃ at 675 °C through different intermediates, [La₂O(CO₃)₂], [La₂O₂CO₃]  at 426 °C and 580 °C respectively. The intermediates of thermal decomposition and final product were confirmed by IR and X-ray diffraction. Coats and Redfern method has been implemented for the  estimation of various kinetic parameters viz. energy of activation (E), pre-exponential factor (A),order of decomposition (n).The thermodynamic parameters like enthalpy of activation (ΔH) entropy of activation (ΔS) and free energy of activation (ΔG) have been calculated by using thermogravimetric data.

Hydrazine ligand; lanthanum complex; Thermal decomposition; Coats; Redfern equation

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