Electrical conductivity, Spectroscopic and thermal studies on chelates of SPADNS with some transition metals

ABSTRACT

The solid complexes of SPADNS 2-[P-sulfonyl] -1,8-dihydroxynaphthalene 3,6-disulfonic acid trisodium salt] with Cr [III], Mn [II], Co [II], Ni [II] and Cu [II] were prepared and subjected to elemental analysis, IR, thermogravimetric and electrical conductivity studies. The optical properties as well as the type of coordination and its role in the conduction mechanism were also studied. Racah constants B and the activation energies delta E were determined and correlated with the covalent characters of the metal-SPANDS bonds within the chelates. The study revealed that both Co and Ni are in the divalent state and are octahedrally coordinated, while Cr is in the trivalent and is also six-coordinated