Thermal analysis study and thermodynamical parameters of some picolinate complexes

Abstract

In the present work, the complexes were synthesized by the interaction between the picolinic acid with some metal ions [Cr(III), Mn(II) and Ni(II)], then salted-in. The geometrical structures and the chemical formula of the complexes were characterized by several techniques, such as, elemental analysis, molar conductivity, thermal analysis, and thermodynamical parameters. The complexes after salting-in were fairly stable under normal atmospheric condition. Salting-in of chromium picolinate complex shows no change in the coordination sphere. The salting-in of bis- picolinato manganese (II) complex in different simple salts, KI and Guanidinium hydrochloride, gives change in water of crystallization after several days; in all cases the complexes contains one extra water molecule. While in the case of Nickel picolinate it gives the same structure with Guanidinium hydrochloride and KI.