Synthesis, spectral and thermal studies on pyrazolatebridged palladium(II) coordination polymers

Synthesis, spectroscopic characterization and thermal behavior of pyrazolate-bridged palladium complexes [Pd(μ-Pz)2]n (1), [Pd(μ-mPz)2]n (2), [Pd(μ-dmPz)2]n (3), [Pd(μ-IPz)2]n (4) {pyrazolate (Pz–), 4-methylpyrazolate (mPz–), 3,5-dimethylpyrazolate (dmPz–), 4-iodopyrazolate (IPz–)} have been described in this work. The exobidentate coordination mode of pyrazolato ligands in 1–4 was inferred on basis of IR spectroscopic evidences. TG investigations indicated that the introduction of substituents at the 4 position in the pyrazolyl moiety into coordination polymers do not affect significantly their thermal stability, whereas at the 3 and 5 position reduced the stability of the main chain. Metal palladium was the final product of the thermal decompositions, which was identified by X-ray powder diffraction.