The characterization of poly(dihalophenylene oxide)s synthesized by solid-state thermal decomposition of manganese phenolate complexes with tetramethylethylenediamine (TMEN) ligand is reported. The complexes prepared with 2,4,6-trichlorophenol (TCP) and 2,4,6-tribromophenol (TBP) have been characterized by FTIR spectroscopy, elemental analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dependence of the polymerization yield on temperature and decomposition time of the complexes has been investigated. Maximum polymerization yield is obtained at 220 degrees C and 48 h. The polymers synthesized from the complexes have been characterized by H-1-NMR and FTIR spectroscopy, DSC, and viscometric measurements. All polymers have a branched structure, a high T-g and low intrinsic viscosity. (C) 1999 Society of Chemical Industry.