New complexes of the non-natural amino acid (p-iodo-phenylalanine) with divalent cobalt and nickel ions have been synthesized. The composition of the complexes is [M(IC6H4CH2CHNH2COO)2]2.5H2O (M=Co, Ni) and the crystal structure belongs to orthorhombic system. Infrared spectra indicate the nature of bonding in the
complex. The first stage in the thermal decomposition process of the complex shows the presence of crystal water. The thermal
decomposition process of cobalt complex differs from that of nickel. The intermediate and final residues in the thermal decomposition
process have been analyzed to check the pyrolysis reactions. Thermal analysis indicates that the iodine atom of the ligand
may coordinate to the metal ion in the lattice.