Gated Channels and Selectivity Tuning of CO₂ over N₂ Sorption by Post‐Synthetic Modification of a UiO‐66‐Type Metal–Organic Framework

Abstract

The highly porous and stable metal-organic framework (MOF) UiO-66 was altered using post-synthetic modifications (PSMs). Prefunctionalization allowed the introduction of carbon double bonds into the framework through a four-step synthesis from 2-bromo-1,4-benzenedicarboxylic acid; the organic linker 2-allyl-1,4-benzenedicarboxylic acid was obtained. The corresponding functionalized MOF (UiO-66-allyl) served as a platform for further PSMs. From UiO-66-allyl, epoxy, dibromide, thioether, diamine, and amino alcohol functionalities were synthesized. The abilities of these compounds to adsorb CO2 and N2 were compared, which revealed the structure-selectivity correlations. All synthesized MOFs showed profound thermal stability together with an increased ability for selective CO2 uptake and molecular gate functionalities at low temperatures.

Post-synthetic modification of zirconium metal–organic frameworks by catalyst-free aza-Michael additions

“…Due to the gradual mass loss in the 120°C-440°C region, 120°C was chosen as the activation temperature, which is consistent with that used in previous studies on UiO-66 derivatives. [36][37][38] The mass loss above 440°C corresponds to decomposition of the framework, and is similar to previous reports for UiO-66-NH 2 and related MOFs. 32,39 These results implies that post-synthetic modification does not alter the thermal stability of UiO-66-NH 2 .…”

The duality of UiO-67-Pt MOFs: connecting treatment conditions and encapsulated Pt species byoperandoXAS

“…The UiO-66/67/68 frameworks are obtained by connecting the 12-fold coordinated Zr 6 O 4 (OH) 4 inorganic cuboctahedron with organic linkers of increasing length, 1,4-benzene-dicarboxylate (bdc), 4,4 0 -biphenyl-dicarboxylate (bpdc) or 4,4 0 -terphenyl-dicarboxylate (tpdc). 42 Because of their high stability, this class of materials is an attractive candidate for a variety of applications in the fields of catalysis, [53][54][55][56][57][58][59][60][61] H 2 , 44 CH 4 , 62,63 and CO 2 61,64,65 uptake, proton conduction, 66,67 removal of air 68 and water 69 contaminants, gas separation, [70][71][72] sensor applications, 73 and radioactive waste scavenging. 74 Also in the case of UiO-66/67/68, functionalization has played an important role in enhancing the material potentialities.…”

Postsynthesis of Titanium Incorporated With Amino-Functionalization Uio-66 for Enhancing Co2 Uptake

“…This is remarkable considering that the small cavities of ~5 Å appear to have a large role in the uptake of CO 2 .The Titanium cooperated with NH 2 -UiO-66 herein illustrate the importance of reactive side groups, introduced in post-synthetic modifications, converted in high yields to functionalities through post-synthetic methods. 40 Moreover, our work highlights the strategies of tailoring host-guest interactions through post-synthetic method, therefore, enabling applications in CO 2 uptake.…”