The synthesis of trihalophenolate cerium (IV) complexes from an aqueous solution and their characterizations by means of FTIR, DSC, elemental analyses, mass spectroscopy, and magnetic susceptibility measurements are described. The thermal polymerizations of these complexes were carried out in the solid state and in the melt. Structural analyses of polymers were performed by H-1-NMR, C-13-NMR, and FTIR spectroscopic analyses; T-g by differential scanning calorimetry; as well as the molecular weights by viscometrical method. It was found that 4-chloro-2,6-bromophenoxide displayed a slightly higher selectivity in favor of 1,2-addition; whereas 1,2- and 1,4-additions took place at equal rates in the case of 2,4,6-tribromophenolate. Complex C I, having tetra-coordination of TBrP per Ce(IV), decomposing at a lower temperature displayed a higher percentage yield, and lower percentage weight loss compared to complex C2. Complex C2 is a hexacoordinated 4-C1-DBrP per Ce(IV) that decomposes at a slightly higher temperature. C2 reached the melting state at a higher temperature (150degreesC) than C1 (120degreesC).