Generic Postfunctionalization Route from Amino-Derived Metal−Organic Frameworks

Abstract

This study deals with the development of a soft, generic, one-pot postfunctionalization method for metal-organic frameworks (MOFs) starting from compounds with an amino group on the linker. The first step consists of transforming the amino group into azide (N(3)) by an unconventional route using tBuONO and TMSN(3). In the same vessel, the desired functionalized MOF then is obtained by the Huisgen 1,3-dipolar cycloaddition of azides to alkynes, otherwise known as the "click" reaction. The method was applied to DMOF-NH(2) and MIL-68(In)-NH(2), which represent two distinct and important classes of MOF. For both, the functionalization was complete (>90% grafting) and the crystallinity was maintained. Thanks to the large diversity and availability of cyano- and acetylene-based chemicals, this method opens the door to tailor-made functionalized MOFs.

Postsynthetic modification of metal–organic framework for hydrogen sulfide detection

“…It is obvious that the aromatic signals of the amine (7 ppm, d, 1H, J = 8.3 Hz; 7.34 ppm, s, 1H; 7.77 ppm, d, 1H, J = 8.3 Hz) (Fig. 3a) does not completely disappear, thus indicating not full conversion to the azide form [53]. Attempts were made to improve the percent conversions for IRMOF-3 by increasing of reaction time to drive modification of the framework.…”

“…Instead, we investigated another pathway that uses mild conditions and involves stable, non-explosive compounds [52]. In a typical synthesis (Scheme 1), the freshly dried IRMOF-3 was treated with tBuONO and TMSN 3 in THF overnight at room temperature to produce the corresponding azide compound IRMOF-3(-N 3 ) [53].…”

Tailoring Metal–Organic Frameworks for CO2 Capture: The Amino Effect

“…Aliphatic amines, on the contrary, are introduced into the MOFs with post-synthesis reactions involving 1) open metal centers [16,17] or 2) pre-existing aromatic ÀNH 2 groups. [35,36] In the first case, the amine is coordinated by the metal center, whereas in the second case the aromatic amino group is converted into a functional group with an aliphatic amine by using aziridine reactions [35] or click chemistry, [36] with the advantage that a chemical bond between the MOF and the amine is formed, assuring the stability of the grafted species.…”

“…In the first step, the interaction with benzene-1,4-dicarboxylic acid has been considered because it represents the basic linker in most MOFs; [17,19,22,25] two cluster models have been adopted: benzene (1) and benzene-1,4-dicarboxylic acid (1'). Three different types of amino functionalities have been then considered: 1) aromatic amines, [14,[19][20][21][22]25] 2) aliphatic amines as part of the substituent group on the ring, [35,36] and 3) aliphatic amines grafted onto an open metal center. [16,17] For the aromatic amines, aniline (2), 2-amino-1,4-benzenedicarboxylic acid (2'), 1,2-aminobenzene (3), and adenine (14) have been used.…”

Gas phase adsorption of alkanes, alkenes and aromatics on the sulfone-DUT-5 Metal Organic Framework

“…Farrusseng et al also post synthetically modified -NH 2 containing MOFs, where in a first step the -NH 2 groups are converted into azides. By means of ''click chemistry'' the azide group is grafted with the desired functional group [9,10]. UiO-66 and MIL-47 were modified with a plethora of functional groups and the effects on the sorption characteristics for CO 2 , water and light alkanes were investigated by us [11,12].…”