Structural versatility of four coordination polymers based on 5-(1-oxoisoindolin-2-yl)isophthalic acid: Magnetic and luminescent properties

Abstract

Four interesting coordination polymers, namely [Co(IDPA)(phen)(H2O)]n (1), [Co(IDPA)(bpp)(H2O)]n·2n(H2O) (2), [Zn(IDPA)(py)]n (3), and [Pb(IDPA)(H2O)]n (4) (H2IDPA=5-(1-oxoisoindolin-2-yl)isophthalic acid, phen=1,10-phenanthroline, bpp=1,3-bis(4-pyridyl)propane, py=pyridine), have been successfully synthesized under solvothermal conditions and structurally characterized. Single-crystal X-ray diffraction analyses indicate that compound 1 shows a zigzag chain, while compounds 2–4 exhibit two-dimensional wavelike or flat layer structures with the same uninodal 4-connected sql topology. These results reveal that different metal centers with the presence of auxiliary ligands maybe play a significant role in the construction process of coordination polymer. Furthermore, compounds 1 and 2 display weak antiferromagnetic interactions in the system. Interestingly, because H2IDPA is a coplanar ligand with large rigid π-conjugated system, it exhibits a strong blue emission with the quantum yield (QY) up to 4.41%. Furthermore, compound 3 is a 2D layer structure and its QY is largely increased to 22.52%. Besides, compound 4 shows a multiple emissions from blue to yellow and falls within the white region of the 1931 CIE chromaticity diagram. Therefore, it is suggested to turn on the fluorescence by building the fluorophore within metal-organic frameworks.