2D lanthanide coordination polymers constructed from semirigid ligand 4-(pyridin-3-yloxy)-phthalic acid: Synthesis, structure and luminescence.

Graphical abstract Tunable luminescence from green to red was successfully achieved by co-doping Eu into isostructural Tb framework. White-light emission was successfully realized by co-doping Eu/Tb into analogic Gd framework. Abstract Three new compounds (Ln–CPs) [Ln(PPDA)(C 2 O 4) 0.5 (H 2 O) 2 ] n · n H 2 O (Ln = Tb (1), Eu (2) and Gd (3)) were synthesized based on semirigid ligand 4-(pyridin-3-yloxy)-phthalic acid (H 2 PPDA) under solvothermal conditions. Ln–CPs 1 – 3 exhibit isomorphic 2D layered network with rhombic windows. Notably, oxalic acid in the resulting framework is formed by in situ reaction under solvothermal and acidic conditions. Solid state luminescent studies indicate that 1 and 2 show characteristic green and red emissions of the corresponding Ln3+ ions, respectively, while 3 exhibits blue emission arising from PPDA2− ligand. Then, by adjusting the co-doping ratio of different Ln3+ ions into the well-defined host framework, a series of codoped Ln–CPs Eu3+-doped 1 and Eu3+, Tb3+-doped 3 are synthesized, showing tunable luminescence emissions including white-light emitting. [ABSTRACT FROM AUTHOR]