High flux X-Ray diffraction instrument for the pair distribution function analysis of MOF

Equipment, AAP 2017-1

Team: IMAP

Project leader : Antoine Tissot

Abstract :

Metal Organic Frameworks or MOFs are a recent and versatile class of porous solids that has been proposed for a wide range of potential applications (gas storage, separation, catalysis, biomedicine…). In most cases, this requires the development of highly stable and functional new MOFs able to resist to the sometimes harsh conditions related to the desired applications (e.g. water, corrosive molecules, low or high pH…). Recent progresses have been obtained with metal(III, IV) polycarboxylates or metal(II) pyrazolates, although there is still a need to develop new functional MOF materials with an enhanced stability. This lead in most cases to poorly crystalline solids due to the very high chemical reactivity of these species in solution, rendering their structural analysis very challenging. Pair Distribution Function, which considers the direct space diffraction data, gives an exhaustive interatomic distances distribution at the short to medium range within a given solid, and is thus an appropriate technique to analyze at the molecular level amorphous or crystalline solids. The project will then consist of collecting, in addition to the usual physicochemical characterizations, PDF data on the new functional MOFs from IMAP, at various temperatures when required, using a new diffractometer equipped with a Mo source and a high energy detector bought thanks to the help of the DIM.