Two new supramolecular compounds based on Ni(II)-Schiff-base and Keggin-type [PMo₁₂O₄₀]³⁻

Abstract

Two polyoxometalate-templated nickel-Schiff-base compounds, {[Ni(L)₂]₂[PMo₁₂O₄₀][Cl] · 1.5DMF · H₂O} _n (1) and {[Ni(L)₂]₂[PMo₁₂O₄₀][Cl] · DMSO · CH₃OH · 0.5H₂O} _n (2) (where L is 1,4-bis(4-imidazolyl)-2,3-diaza-1,3-butadiene), were synthesized in situ from Ni²⁺ and L in H₂O/DMF/CH₃OH or H₂O/DMSO/CH₃OH at room temperature and characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. The results of the single-crystal X-ray diffractions suggested that both compounds have the same packing of the Ni(II)-Schiff-base cation layer and Keggin anion layer. Thermogravimetric analyses suggested that two supramolecular compounds have similar thermal stabilities based on the same packing of the cation and anion layers.

Keywords:

• Supramolecular compound
• Metal Schiff-base
• Crystal structure
• Polyoxometalate

Acknowledgments

This study is supported by the National Natural Science Foundation of China (grant no. 20971038) and the Natural Science Foundation of the Education Department of Henan Province (no. 2009A 150015).