Rare‐Earth Multivariate Metal–Organic Frameworks: Cationic Radius Biased Compositional Control and Property Tuning
Adnan Ishaq, Joseph O. Ogar, Asif Raza, Musa M. Mahmud, Jacob L. Brownlee, Danielle E. Schier, Stephen P. Argent, Lucy Clark, Soumya Mukherjee, Neil R. ChampnessABSTRACT
The synthesis of a multivariate metal–organic framework (MTV‐MOF) family, [Ln(DNNDI) 1.5 ] n ( UoB‐116 ), is reported (DNNDI: N , N' ‐bis(dinicotinate)‐1,4,5,8‐naphthalenetetracarboxydiimide). UoB‐116(Ln) is formed by 15 different metals (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), all of which were shown to be isoreticular. The uniformity of the framework structure facilitated the synthesis of MTV‐MOFs with 2, 4, 12, 15, or 16 (including In(III)) different metals. Single crystal structures of each unimetallic MOFs and MTV‐MOFs with 12 or 16 metals were determined, confirming the isoreticular nature of this family of MOFs. Energy Dispersive X‐ray (EDX) analysis confirmed distribution of each metal throughout crystals of the MTV‐MOFs and compositional analysis indicated increased concentration of lanthanides with smaller cationic radius. A protocol was developed to control relative composition in bimetallic systems, UoB‐116(La 1‐x Lu x ) and UoB‐116(Dy 1‐x La x ) ( x = 0–1). In the case of UoB‐116(Dy 1‐x La x ) it is shown that the porosity, magnetism and UV–visible properties can be tuned through metal cation composition.