Thermal, Spectral and Magnetic Studies of Fluorenone Anthranilic Acid Complexes of Manganese(II), Cobalt(II) and Nickel(II)

Department of Chemistry, University of Calicut, Kerala-673 635
Manuscript received 2 July 1993, accepted 16 November 1993

Fluorenoneanthranilic acid, a novel Schiff base, forms 1 : 1 complexes with Mn^II, Co^II and Ni^II acetates. All the complexes are found to be non-electrolytes in nitrobenzene, and octahedral structures are assigned to them based on electronic and magnetic data. Ir studies reveal that the complexes are formed by the replacement of the hydrogen atom of the COOH group by the metal with the azomethine nitrogen coordinating to the metal. The thermal decomposition of the [ML(Ac)(H20)3] chelates was studied by TG and DTA techniques. The mechanism of the decomposition has been established from TG data. The kinetic parameters, namely, activation energy (E), pre-exponential factor (A) and entropy of activation (ΔS) were calculated from TG curves using mechanistic and non-mechanistic equations. On the basis of our findings, the relative thermal stabilities of the three chelates have been evaluated.