Encapsulation of Ln3+ hydrate species for tunable luminescent materials based on a porous Cd(II)-MOF

This work builds on the recently developed guest-driven approach for the construction of tunable luminescent materials based on porous metal-organic frameworks (MOFs). The porous heteroatom-rich Cd(II)-MOF (1) material has been obtained by the reaction of Cd(NO3)(2) with 3,5-bis(3-carboxyphenyl)-1,2,4-triazole)/4,4'-bis(4-pyridyl)ethane in solution. Compound 1 features (4,4) sheets which interlock together to generate a 2-fold interpenetrating robust framework containing ellipse-like channels with pore dimensions of ca. 9 x 11 angstrom. In particular, 1 is able to trap lanthanide hydrate cationic species such as Eu(H2O)(8)(3+) and Tb(H2O)(8)(3+) and to sensitize their emissions in the solid state. Furthermore, the emission colors could be tuned by changing the co-doped Eu3+/Tb3+ ratio in the Cd(II)-MOF to provide barcode-like luminescent materials.