Phosphonate monoesters as carboxylate-like linkers for metal organic frameworks

Metal-organic frameworks (MOFs) represent a new class of hybrid organic-inorganic supramolecular materials comprised of ordered networks formed from organic electron donor linkers such as carboxylates or aminesand metal cationssuch as Zn+۲.[۱] They can exhibit extremely high surface areas, as well as tunable pore size and functionality, and can act as hosts for a variety of guest molecules. Since their discovery, MOFs have enjoyed extensive exploring, with applications ranging from gas storage to drug delivery to sensing.[۲]The topology of MOFs is intimately related to both the coordination environment favored by the metal ion and the geometry of the organic “linker” groups, which together form so-called secondary building units that establish the network symmetry. These characteristics further distinguish MOFs from other classes of porous materials, such as aerogels, which are amorphous, and ordered or partially ordered materials created from block copolymers.Bidentatephosphonate monoesters are analogues of popular dicarboxylate linkers in MOFs, but with analkoxy tether close to the coordinating site. Herein, wereport ۳-D MOF materials based upon phosphonate mono-ester linkers. Cu( ۱,۴-benzenediphosphonate bis (monoalkylester), CuBDPR, with an ethyl tether is nonporous; however, the methyl tether generates an isomorphous frameworkthat is porous and captures CO۲with a high isosteric heatof adsorption of ۴۵ kJ/mol.

کلیدواژه ها:

Metal organic framework ، carbon dioxide capture ، enthalpy of adsorption ، porous material.