title: Framework-Topology-Dependent Catalytic Activity of Zirconium-Based (Porphinato)zinc(II) MOFs.
abstract: Catalytic activity for acyl transfer from N-acetylimidazole (NAI) to different pyridylcarbinol (PC) regioisomers (2-PC, 3-PC, and 4-PC) is demonstrated for a set of topologically diverse, zirconium-based (porphinato)zinc metal-organic frameworks (MOFs). The MOFs studied are PCN-222, MOF-525, and NU-902, which are based on the csq, ftw, and scu topologies, respectively. The experimentally obtained reaction kinetics are discussed in light of molecular modeling results. The catalytic activity is shown to vary across the series of MOFs due to the different extent to which each topology facilitates reactant preconcentration and alignment of PC and NAI via coordination to framework porphyrin sites (orientation effects). Trends of experimental initial reaction rates with MOF topology and PC regioisomer are consistent with preconcentration effects, which depend on the number of porphyrin sites per volume of MOF, as well as with orientation effects, which depend on the number of porphyrin pairs per volume of MOF that bind PC and NAI in such a way that they are primed to form the required transition state. The present work shows how the proper alignment of catalytic linkers can enhance reaction rates in MOFs.
authors: Department of Chemistry, Southern Illinois University , 1245 Lincoln Drive, Carbondale, Illinois 62901, United States.
authors: Pravas
authors: P
authors: Deria
authors: Diego A
authors: DA
authors: Gómez-Gualdrón
authors: Idan
authors: I
authors: Hod
authors: Randall Q
authors: RQ
authors: Snurr
authors: Joseph T
authors: JT
authors: Hupp
authors: Department of Chemistry, Faculty of Science, King Abdulaziz University , Jeddah 21589, Saudi Arabia.
authors: Omar K
authors: OK
authors: Farha