Lanthanide-organic frameworks constructed from multi-functional ligands: Syntheses, structures, near-infrared and visible photoluminescence properties

A series of multi-functional ligands supported lanthanide-organic frameworks, formulated as [Ln(HL1)(H2L2)0.5(H4L2)0.5(H2O)]·(H2O)1.5·{Ln=La (1), Pr (2), Nd (3), Sm (4), Eu (5); H3L1=5-Sulfosaclicylic acid; H4L2=N,N′-piperazine (bis-methylene phosphonic acid)}, have been synthesized by hydrothermal reactions. Single crystal X-ray diffractions and powder XRD patterns confirm they are isostructural. They feature 3D framework structures based on extension of a “zigzag” inorganic chain by organic linkers. Moreover, the photoluminescence properties of 5 and 3 have been investigated, and they show strong solid‐state emissions in the visible and near-infrared (IR) regions at room temperature.