Metastable Sorption State of a Metal-Organic Porous Material Determined by In Situ Synchrotron Powder Diffraction

摘要

Metal–organic microporous materials (MOMMs)[1] have attracted the attention of scientists for a number of reasonsincluding the creation of nanometer-sized spaces, discovery ofnovel phenomena, and commercial interests such as their application in gas separation,[2] gas storage,[2,3] and heterogeneous catalysis.[4] Recent activity in crystal engineering has provided several examples of MOMMs which have rigid open frameworks and therefore the potential to be functionally related to zeolites. In fact, MOMMs often have a much more dynamic framework than is generally believed, and this ischaracteristic of metal–organic species.[5] Dynamic pores could come from a sort of “soft” framework with multistability, whose states go back and forth between two counterparts; or a system could exist in one or two statesfor the same values of external field parameters. The structural rearrangement of the host framework in responseto guest molecules proceeds from the “open” phase to the closed” phase.