3-D supramolecular architectures in the three new complexes constructed from mixed ligands: Syntheses, crystal structures, spectroscopic properties, XRPD and thermal study

Three new coordination polymers [Cu2(bptc) (bpdap)2]·4H2O (1), {Zn2(bptc)(bpe)(H2O)6}n (2) and {Co2(bptc)(bpe)(H2O)8}n (3) [H4bptc = 3,3′,4,4′-biphenyltetracarboxylate acid, bpdap = N,N′-bis(2-pyridyl)-2,6-diaminopyridine, bpe = trans-1,2-bis(4-pyridyl)ethene] have been hydrothermally synthesized in different pH values and structurally characterized by single-crystal X-ray diffraction. The non-covalent interactions of hydrogen bond extend complexes 1, 2 and 3 into supramolecular architectures, where 1 exhibits a 3-D framework with 1-D open channels where the guest water molecules are located. Importantly, two kinds of chiral helical H-bonded chains appear in 1, and some types of H-bonded patterns exist in 1, 2 and 3. It is more remarkable that the building block bptc anion adopts versatile coordination modes in these complexes. The elemental analysis, IR spectra, XRPD and TG analysis are discussed for 1, 2 and 3. In addition, the fluorescence is also studied for 2 here.