Synthesis, characterization and thermal degradation of oligo-2-[(4-fluorophenyl) imino methylene] phenol and some of its oligomer-metal complexes

In this study, the oxidative polycondensation reaction conditions of 2-[(4-fluorophenyl) imino methylene] phenol (FPIMP) with air oxygen and NaOCl were studied in an aqueous alkaline medium between 60 and 90 °C. Synthesized oligo-2-[(4-fluorophenyl) imino methylene] phenol was characterized by 1H-NMR, FT-IR, UV–Vis, size exclusion chromatography (SEC) and elemental analysis techniques. The yield of oligo-2-[(4-fluorophenyl) imino methylene] phenol (OFPIMP) was found to be 62.00% (for air O2 oxidant) and 97.70% (for NaOCl oxidant) at the optimum reaction conditions. According to the SEC analysis, the number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) values of OFPIMP were found to be 1370 g mol−1, 1979 g mol−1 and 1.45, using NaOCl, 2105 g mol−1, 2557 g mol−1, and 1.22, using air O2, respectively. During the oxidative polycondensation reaction, (2.88%) a part of –CHN group oxidized to carboxylic acid (–COOH). TG and TG-DTA analyses were shown to be more stable of oligo-2-[(4-fluorophenyl) imino methylene] phenol and its oligomer metal complexes than monomer against thermo-oxidative decomposition. The weight loss of OFPIMP was found to be 97.00% at 900 °C. The weight losses of OFPIMP-Co, OFPIMP-Ni OFPIMP-Cu oligomer-metal complex compounds were found to be 88.66%, 94.36% and 83.21%, respectively, at 1000 °C.