Trinuclear and dinuclear Ni(II) complexes constructed by bridging oxygen: crystal structures, magnetic, and thermal properties

Abstract

The reaction of H₂L (N,N ′-bis(5-ethyl-1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide) with Ni(II) salts gave crystals of two new complexes, [Ni₃(µ₃-O)(H₂L)(L)₂] · 2DMF (1) and [Ni₂(µ-H₂O)(CH₃OH)(DMF)(L)₂] · H₂O · CH₃OH (2). The complexes were characterized by elemental analysis, IR, thermal analysis, and X-ray single crystal diffraction. Complex 1 is a trinuclear complex containing a triangle frame in the center formed by three Ni(II) atoms with a bridging µ₃-O. Complex 2 is dinuclear formed by two Ni(II) atoms with a bridging H₂O. H₂L coordinates to metal centers as a pentadentate ligand in 1 and tetradentate in 2. Thermal analysis shows that the thermal stability of 1 is higher than that of 2. In addition, the magnetic properties of 2 are also reported.

Keywords:

• Ni complex
• Crystal structure
• Thermal decomposition
• Magnetic properties

Acknowledgment

This work was financially supported by the National Science Foundation of China (20971111).