Designing Functional Metal–Organic Frameworks by Imparting a Hexanuclear Copper-Based Secondary Building Unit Specific Properties: Structural Correlation With Magnetic and Photocatalytic Activity

In
continuation of our research interest in pyrazole-based multifunctional
metal organic frameworks (MOFs), we report here three Cu­(II) MOFs
using pyrazole and various aromatic carboxylic acid-based ligands.
The main theme of interest is to design functional MOFs by imparting
a multinuclear metal center as a secondary building unit (SBU). Accordingly,
three MOFs are synthesized based on a hexanuclear Cu-pyrazolate unit
as the SBU with some intriguing structural networks like (4,4) type
herringbone grid or an archetypal Kagomé topology. We have
successfully synthesized functional MOFs by incorporating hexanuclear
Cu-pyrazolate SBU-specific properties viz. magnetism and catalysis,
the central theme of this work. All the MOFs show some photocatalytic
degradation of toxic dye molecules. On the other hand, magnetic behaviors
of MOF-2 and MOF-3 associated with the Cu6 unit have also been investigated.