Structural influencing factors on ZnII/CdII coordination polymers based on a “V”-like bis-pyridyl-bis-amide derivative: Construction, fluorescent sensing and photocatalysis properties

• A “V”-like bis-pyridyl-bis-amide was used to construct seven ZnII/CdII complexes.
• The polycarboxylates and the metals have great effect on the structures of 1–7.
• Complexes 1–7 show from 1D to 2D architectures, respectively.
• The fluorescent sensing behaviors of 2, 3, 6 toward organic solvents were reported.
• The photocatalytic activities of complexes 1–7 have been reported.

Seven ZnII and CdII metal–organic coordination polymers based on the mixed ligands of a semi-rigid “V”-like bis-pyridyl-bis-amide and five aromatic polycarboxylates, namely [Cd(3-bpha)(1,3-BDC)(H2O)]·3H2O (1), [Cd(3-bpha)(MIP)(H2O)]·H2O (2), [Cd(3-bpha)(1,3,5-HBTC)(H2O)]·3H2O (3), [Cd(3-bpha)(HIP)]·3H2O (4), [Zn(3-bpha)(HIP)]·3H2O (5), [Zn(3-bpha)(MIP)] (6) and [Zn(3-bpha)(NIP)] (7) (3-bpha = N,N′-bis(pyridin-3-yl)-5-hydroxybenzene-1,3-dicarboxamide, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, H2MIP = 5-methylisophthalic acid, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid, H2HIP = 5-hydroxyisophthalic acid and H2NIP = 5-nitroisophthalic acid), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectra, powder XRD and TG analysis. X-ray analyses reveal that complexes 1–3 and 5 are similar 1D channel-like structures. Complex 4 is a (2,3,5)-connected 2D network with (42·6)(43·6·84·102)(4) topology. Complexes 6 and 7 are isostructural 2D 4-connected networks. The 2D supramolecular structures of complexes 1 and 3 and the 3D supramolecular architectures of complexes 2 and 4–7 are formed through hydrogen-bonding interactions. The effect of metals and polycarboxylate auxiliary ligands with different substitute groups, different carboxyl positions and number on the dimensionalities and structures of the target complexes were discussed. The fluorescent sensing behaviors of 2, 3 and 6 toward different organic solvents have been investigated in detail.

Seven metal–organic coordination polymers have been hydrothermally synthesized using a “V”-shaped bis-pyridyl-bis-amide derivative (3-bpha) as the main ligand and five organic polycarboxylates as the auxiliary ligands. The effects of the central metals and polycarboxylates on the structures of coordination polymers have been discussed.Figure optionsDownload as PowerPoint slide