Kinetic parameters and thermal stability of metalloporphyrins

摘要

Metalloporphyrins have relatively high thermal stability, which makes them attractive candidates for high temperature catalytic process [1]. Thermogravimetry (TGA) have been used to examin the thermochemistry, to study the thermal stability and thermal decomposition of the new complexes of porphyrins. The composition of these compounds were determined from the TGA curves. A systematic study of the stability of tetra-p-phenyl-porphyrin (TPP) and its metallic complexes with [Ni(II), Co(II), Mg(II), Ti(IV), W(VI) and VO(IV)] through thermogravimetry (TGA/DTG) has been carried out.Metal complexes derived from porphyrins are fairly stable to thermal and oxidative decomposition, and parameters of that process depend on the number of axial ligands. The central metal ions have some marked influence on the thermal stability of the compounds [2]. All these compounds are stable up to the temperature range 400-600 ℃ and decompose in an almost single major stage, which is used for kinetic parameters evaluation, In certain cases, a second minor decomposition stage is obtained.