Abstract:
Four new 2D coordination polymers (CPs) of Cd(II), [Cd(tfbdc)(bpy)(H2O)2]n (1) [Cd(tfbdc)(bpe)(H2O)2]n (2),
[Cd(tfbdc)(4bpdb)(H2O)2]n (3), and [Cd(tfbdc)(3bpdb)(H2O)2]n (4) (where, tfbdc ¼ 2,3,5,6-tetrafluoro-1,4-
benzenedicarboxylate, bpy ¼ 4,4’-bipyridine, bpe ¼ 1,2-bis(4-pyridyl)ethylene, 4bpdb ¼ 1,4-bis(4-pyridyl)-2,3-
diaza-1,3-butadiene), and 3bpdb ¼ 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene) were successfully synthesized by
room temperature self-assembly of Cd(II), tfbdc2 and the N, N’-bipyridine linkers. All four CPs were thoroughly
characterized by single-crystal X-ray diffraction and other physicochemical studies. Structural analysis revealed
that CPs 1–4 feature a 2D network structure which is further extended to 3D supramolecular framework via
intermolecular (O–H⋯O) hydrogen bonding interactions between the hydrogens of the coordinated water
molecule and the free carboxylate oxygen of tfbdc2 dianion. Further, the use of various ancillary bipyridine
linkers has resulted in the 2D networks 1–4 with different pore sizes. Interestingly, 1–4 exhibit water stability
owing to the presence of fluorinated aromatic dicarboxylate ligand and also, photoluminescence emission
attributed to intra-ligand and/or ligand-to-ligand charge transfer transitions.
