Structural Diversity of Three Pyrazoyl-Carboxyl Bifunctional Ligand-Based Metal-Organic Frameworks: Luminescence and Magnetic Properties.

Three metal-organic frameworks (MOFs), [Cd(Hpzbpdc)(H O)]⋅H O (1), [Mn (Hpzbpdc) (dmf) ] (2), and [H N(CH ) ] [Eu(Hpzbpdc) (HCOO) (dmf) ]⋅DMF⋅0.5 H O (3) (H pzbpdc=4'-(2 H-pyrazol-3-yl)biphenyl-3,5-dicarboxylic acid), have been solvothermally synthesized from one pyrazoyl-carboxyl bifunctional ligand and characterized by single-crystal structures. The H pzbpdc ligand in 1-3 displays various coordination modes through the pyrazoyl and carboxyl groups. Both 1 and 3 contain dinuclear cluster building units and reveal a four-connected gismondine (gis) zeolite 3D framework and a 2D grid layer structure, respectively. Compound 1 shows blue luminescence, compound 3 reveals red luminescence that arises from efficient energy transfer from the organic ligand to the europium(III) ion, and compound 2 reveals an uncommon (3,8)-connected tfz-d; UO net with a rare Mn (COO) cluster and shows antiferromagnetic interactions between the manganese(II) ions.