Six new coordination polymers constructed by 3-carboxyl-5-oxycarboxymethylpyridinio-1-carboxylate: Crystal structures, topologies, photoluminescent and magnetic properties

• A new asymmetric flexible tricarboxylate ligand of 3-carboxyl-5-oxycarboxymethylpyridinio-1-carboxylate was synthesized.
• Six new two-dimensional (2D) coordination polymers have been hydrothermally obtained.
• 1, 2, 3, 4 are isostructural and feature a binodal (4,6)-connected topology with left- and right-handed helical chains.
• The photoluminescent properties of 1, 2, 5, 6 and magnetic properties of 3, 4 have been studied.

Six new two-dimensional (2D) coordination polymers, [ML(H2O)3]n (M=Zn (1), Cd (2), Mn (3), Co (4)), [CdL(H2O)]n (5), [CdL(4,4′-bipy)]n·nH2O (6), (H2L=3-carboxyl-5-oxycarboxymethylpyridinio-1-carboxylate, 4,4′-bipy=4,4′-bipyridine), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction analyses, IR spectra, and thermogravimetric analyses. 1, 2, 3, 4 are isostructural and feature a binodal (4,6)-connected topology with left- and right-handed helical chains with a pitch of 9.9560 Å. 5 can be topologically presented as an uninodal 6-connected network if the hydrogen bonds are also considered. 6 is a binodal (3,5)-connected 2D layer network. The photoluminescent properties of 1, 2, 5, 6 and magnetic properties of 3, 4 have been studied and discussed.

The structural differences show that the ligand, the metal center, and the reaction conditions have great influence on the structure of the final assembly. Figure optionsDownload as PowerPoint slide