Functionality proportion and corresponding stability study of multivariate metal-organic frameworks

摘要

Multivariate metal-organic frameworks(MTV-MOFs) with different ratios of terephthalate(BDC) linker and amino-benzenedicarboxylate(BDC-NH2) linker were synthesized through both direct synthesis from linker mixture and linker exchange of activated single-linker MOFs. Functionality proportion was impacted by the thermodynamics during the one-pot MOF construction, resulting in preference of BDC over BDC-NH2 in the MTV-MOF, in agreement with the quantum mechanics calculations. The functionality difference also affects the thermodynamics in the linker exchange process, as indicated by the more effective linker exchange in BDC-NH2-based IRMOF-3 than in BDC-based MOF-5. Furthermore,the thermal decomposition temperatures and chemical integrity upon ambient air exposure of these MOFs with variate functionalities were investigated, and it reveals that higher proportion of BDC in the MTV-MOF crystals contribute to both higher thermal and higher chemical stabilities.