Mapping‐Out Catalytic Processes in a Metal–Organic Framework with Single‐Crystal X‐ray Crystallography

Abstract

Metal-organic Framework (MOFs) materials are well known for their ultra-high surface areas and gas storage and separation properties. One strategy for enhancing the performance characteristics of MOFs is to post-synthetically line the pores with metal ions. Although this technique has led to improved gas separations the precise structural characterization of the 'metalated' MOF has proved elusive. Here we present that the post-synthetic addition of metals can give rise to materials with the potential to be developed for catalysis and gas adsorption. In addition the high crystallinity of MOFs allow for following reaction products via single crystal X-ray diffraction analysis [1]. 1. Burgun et. al. Angew. Chem. Int. Ed.

A robust Th-azole framework for highly efficient purification of C2H4 from a C2H4/C2H2/C2H6 mixture

“…1 51,56,57 . As we know, the N,O-donor ligands such as azole series have been attested to be an excellent organic linkers to construct a great number of MOFs (more than 900 tetrazolebased MOFs and more than 5000 triazole-based MOF from CCDC data) [58][59][60] . However, there is no Zr-based or Th-based MOFs built on N,O-donor ligands.…”

Self-Assembly of Catalytically Active Supramolecular Coordination Compounds within Metal–Organic Frameworks

“…This is mainly a direct consequence of two unique features of MOFs: (i) a rich host-guest chemistry, which can be tailored by a fine control over the size, shape and functionality of MOFs channels, [30][31][32][33][34][35] and (ii) the possibility to use singlecrystal X-ray crystallography as a definitive characterization tool, which offers the unique possibility -among porous materials-to contrast the success of synthetic methodologies, and even more important, to follow/understand what is actually happening within MOFs channels . [36][37][38][39][40] So far, this has been reflected on the considerable advances performed in such diverse fields as the adsorption and separation of guest gases [41][42][43][44][45] or small molecules, [46][47][48] and catalysis. [49][50][51][52][53][54] However, even if some advances have been recently done related with molecular recognition 55,56 and/or encapsulation of complex molecular systems, [57][58][59] there is still much work to be done in relation to the use of MOFs as chemical nanoreactors.…”

Observation of an Intermediate to H2 Binding in a Metal–organic Framework

“…While many classical examples involve electron-poor metal cations that interact with adsorbates largely through electrostatic interactions, unsaturated electron-rich metal centers housed within porous frameworks can often chemisorb guests amenable to redox activity or covalent bond formation. [5][6][7][8][9] Despite the promise that materials bearing such sites hold in addressing myriad challenges in gas separations and storage [10][11][12] , very few studies have directly interrogated mechanisms of chemisorption at open metal sites within porous frameworks. Here, we show that H2 chemisorption at the trigonal pyramidal Cu + sites in the metalorganic framework Cu I -MFU-4l 13 occurs via the intermediacy of a metastable physisorbed precursor species.…”

“…Certain zeolites and metal-organic frameworks feature coordinatively-unsaturated metal cations that can act as strong adsorption sites for various guest species, although the typically electron-poor nature of these sites tends to favor physical, rather than chemical, adsorption processes [1][2][3][4] . There has, however, been a growing interest in the synthesis of porous materials bearing electron-rich metal sites primed to engage in covalent interactions with small molecule adsorbates [5][6][7][8][9] . While such adsorbents may engender more exothermic adsorption and therefore higher uptake capacities, chemisorption can also give rise to transport-independent activation barriers akin to those often observed on surfaces [14][15] .…”