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

Synthesis, spectroscopic characterization and thermal behavior of pyrazolate-bridged palladium complexes [Pd(mu-Pz)2]n (1), [Pd(mu-mPz)2]n (2), [Pd(mu-dmPz)2]n (3), [Pd(mu-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.