Cyclopentaneteracarboxylic Metal–Organic Frameworks: Tuning the Distance between Layers and Pore Structures with N‑Ligands

Five new isomorphic
coordination polymers of the Co­(II) ion, namely,
{[Co2L­(bpy)0.5(H2O)2]·2H2O}n (1), {[Co2L­(pbyb)0.5(H2O)2]·3H2O}n (2), {[Co2L­(dpe)0.5(H2O)2]·2H2O}n (3), {[Co2L­(dpa)0.5(H2O)2]·2.5H2O}n (4), and {[Co2L­(dip)0.5(H2O)2]·3.5H2O}n (5) (H4L = cis,cis,cis,cis-1,2,3,4-cyclopentaneteracarboxylic acid, bpy
= 4,4′-bipyridine, pbyb = 1,4-di­(pyridine-4-yl)­benzene, dpe
= 1,2-di­(pyridine-4-yl)­ethane, dpa = (E)-1,2-di­(pyridin-4-yl)­diazene,
and dip = 1,4-di­(1H-imidazol-1-yl)­benzene), have
been synthesized under hydrothermal conditions. The L4– ligand maintains its original conformation of SSRR in all of these compounds, but {Co5L}n clusters show mirror coordination symmetry in 1, 2, and 4 while the clusters in 3 and 5 do not. The addition of different N-ligands
can tune the distance between {Co2L}n layers and change the pore structures of the frameworks. Magnetic
susceptibility measurements indicate that 1–5 exhibit antiferromagnetic behavior.