Effect of N-methyl imidazole and dimethyl pyrazole ligands on polymerization of di(2,4,6-trichlorophenolato)Cu(II)/Co(II) complexes in solid state

Kisakurek D.

JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY, no.9, pp.1071-1086, 2004 (SCI-Expanded) identifier identifier


Polymerization of 2,4,6-trichlorophenol (TCPH) was achieved through the thermal decomposition of the copper and cobalt complexes of TCPH with N-containing ligands [N-methyl imidazole (NMIz) and 3,5-dimethyl pyrazole (DMPz)). The structural analysis of the complexes was performed by using Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), mass (MS), UV-VIS, diffuse reflectance (DRS) and electron spin resonance (ESR) spectroscopies, magnetic susceptibility balance and elemental analyses. Polymerization was achieved either in solid state or in melt, and the polymers were characterized by FTIR, nuclear magnetic resonance (NMR) spectroscopy, DSC, and viscosity measurements. The effects of the temperature and time dependencies of %Conversion on polymer synthesis were investigated. The cobalt complexes (having higher decomposition temperatures) were more stable than copper complexes (decomposing at lower temperatures). Thermal stability with respect to N-ligand shows that the complexes with NMIz are more stable than DMPz complexes of the same metal. The highest molecular weights (Mw) were achieved at the end of 3 hr of polymerization for C1 at 170 degreesC, C2 at 120 degreesC, and C4 at 150 degreesC. The longer time at lowest conversion leads to highest Mw of C1 at 125 degreesC at the end of 24 hr, C2 at 90 degreesC at the end of 72 hr and at 100 degreesC at the end of 48 hr.