A dinuclear nickel(II) complex with dissimilar bridges: synthesis, crystal structure, and magnetic characterization

Abstract

Using 3,5-pyrazoledicarboxylic acid (H₃pdc), 2,2-bipyridine (2,2-bipy) and NaN₃, a dinuclear nickel(II) compound with dissimilar bridges, [Ni₂(2,2-bipy)₂(pdc)(N₃)(H₂O)₂] ⋅ 2H₂O (1), has been isolated under hydrothermal conditions. Compound 1 is dinuclear, bridged by two nitrogens in the pyrazole ring of pdc³⁻ and µ_1,3 . The dinuclear units and lattice water molecules are further linked by extensive hydrogen bonds to form 2-D infinite planes, which are further linked through π–π stacking to construct a 3-D supramolecular structure. Variable temperature magnetic susceptibility of 1 from 2 to 300 K indicates anti-ferromagnetic interactions. The magnetic exchange coupling constants J = −12.65 cm⁻¹ and zj ′ = 3.34 cm⁻¹ for 1 can be obtained through the fit of the magnetic data.

Keywords:

• Dinuclear complex
• Hydrothermal synthesis
• 3,5-Pyrazoledicarboxylic acid
• Dissimilar bridges
• Magnetic property

Acknowledgments

This work was supported by the National Natural Science Foundation of China (No. 20971099) and the Natural Science Research Foundation of Education Minister, Henan province (2008A150017).