The scientists, from the University of Versailles, have worked in collaboration with the ID31 beam line at the European Synchrotron Radiation Facility (ESRF) to design and characterise a range of microporous materials, currently headed by MIL-101 which is said to be of potential use in drug delivery, gas storage and a range of other applications.
This new, crystalline material is representative of a class of compounds, known as metal organic framework materials, (MOFs). Depending on their structure and pore size, these materials allow molecules of only certain shapes and sizes to enter the pores, a property known as shape selectivity. The environment within the pores can be very different to that outside, thus promoting chemical reactions that do not occur in the bulk material.
Another prospective use is as templates for forming calibrated, monodisperse nanomaterials. In this respect, the larger the pores, the wider the range of reactants that can be manipulated or stored.
The researchers first synthesised discrete multi-atom building units were designed and generated in solution. Secondly, with the aim of producing a compound with large pores, the building units were combined to produce larger units. The third task was to overcome the challenge that it is increasingly difficult to grow highly diffracting single crystals as structures grow larger. Based on their understanding of the ways the building units might combine, possible structural models were predicted and assessed via a computational strategy that calculated their relative stability.
"This breakthrough opens up a new field for targeted chemistry, computational methods for structure prediction and most importantly novel materials with useful applications," claim the scientists.
The research that led to the synthesis of MIL-101 is published in the 28 September edition of the journal Science.