title: Functionalized defects through solvent-assisted linker exchange: synthesis, characterization, and partial postsynthesis elaboration of a metal-organic framework containing free carboxylic acid moieties.
abstract: Intentional incorporation of defect sites functionalized with free carboxylic acid groups was achieved in a paddlewheel-based metal-organic framework (MOF) of rht topology, NU-125. Solvent-assisted linker exchange (SALE) performed on a mixed-linker derivative of NU-125 containing isophthalate (IPA) linkers (NU-125-IPA) led to the selective replacement of the IPA linkers in the framework with a conjugate base of trimesic acid (H3BTC). Only two of the three carboxylic acid moieties offered by H3BTC coordinate to the Cu2 centers in the MOF, yielding a rare example of a MOF decorated with free -COOH groups. The presence of the -COOH groups was confirmed by diffuse reflectance infrared Fourier-transformed spectroscopy (DRIFTS); moreover, these groups were found to be available for postsynthesis elaboration (selective monoester formation). This work constitutes an example of the use of SALE to obtain otherwise challenging-to-synthesize MOFs. The resulting MOF, in turn, can serve as a platform for accomplishing selective organic transformations, in this case, exclusive monoesterification of trimesic acid.
authors: Department of Chemistry and International Institute for Nanotechnology and ‡Department of Chemical and Biological Engineering, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors: Olga
authors: O
authors: Karagiaridi
authors: Nicolaas A
authors: NA
authors: Vermeulen
authors: Rachel C
authors: RC
authors: Klet
authors: Timothy C
authors: TC
authors: Wang
authors: Peyman Z
authors: PZ
authors: Moghadam
authors: Salih S
authors: SS
authors: Al-Juaid
authors: J Fraser
authors: JF
authors: Stoddart
authors: Joseph T
authors: JT
authors: Hupp
authors: Omar K
authors: OK
authors: Farha