Synthesis and magnetic properties of complexes of a conjugated hyperbranched polymer containing bithiazole rings

A novel conjugated hyperbranched polymer containing bithiazole rings (PBTADB) was synthesized by polycondensation of 1,3,5-benzenetricarboxaldehyde and 2,2′-diamino-4,4′-bithiazole (DABT). The structure of the hyperbranched polymer was confirmed by FT-IR and ¹H-NMR. PBTADB dissolved in organic polar solvents such as DMSO and NMP. Bithiazole rings were introduced to provide bidentate N-donor sites for binding metal ions. The metal complexes were prepared by chelation of the polymer with Co²⁺ and Sm³⁺. The magnetic behavior of coordination compounds was measured as a function of magnetic field strength (0?4.8 × 10⁶ A/m) at 5 K and as a function of temperature (5–300 K) at magnetic field strength of 2.4 × 10⁶ A/m. The magnetic hysteresis loops of PBTADB-Sm³⁺ and PBTADB-Co²⁺ showed the typical ‘S’ shape at 5 K with the Curie-Weiss temperature T _θ = 96 K and 41 K respectively. The results show that they exhibit properties of soft ferromagnetic materials.