Highlighted Publications by Topic
One of principal interests of our group are reactions conducted through the use of mechanical force. Mechanochemistry allows the rapid, low-energy and quantitative synthesis of a number of useful products. As such, milling provides a "greener" approach to chemical synthesis that can help enable us to avoid problems with solution chemisty such as solubility, solvent cost, and sustained heating. We typically conduct milling in either shaker mills (Retsch® MM400) or planetary mills (Retsch® PM400) both classes of which are already widely used in industry (although not for chemical synthesis). A few topics which we are investigating using mechanochemistry include: thiourea organocatalysts, porous metal organic frameworks, pharmaceutical cocrystals and salts, nanoparticle synthesis, organometallic complex synthesis, as well as effects of mechnochemistry on fundamental organic reactions (Wittig, Diels Alder, etc.). For more information on these topics please consult our Projects page or our Full List of Publications. A few recent representative publications are highlighted below.
In Situ Monitoring of Milling Reactions
In a 2011 collaboration with the ESRF and scientists from Institute Ruder Boskovic, our group pioneered the monitoring of milling reactions with via X-ray diffraction in order to better understand the mechanisms which govern milling reaction. These experiments have revealed milling reactions to be highly dynamic with reaction rates comparable or greater than solution chemistry. We have applied this technique to monitor the effects of catalytic additives in milling reactions, pharmaceutical cocrystal formation, as well as metal organic framework synthesis. The results have been published in Nature Chemistry, Nature Protocols, and Angewandte Chemie respectively.
2) Accelerated Ageing
Taking inspiration from biologically-induced mineralization to form metalorganic materials from raw inorganic materials such as oxides, sulfides, and phosphates, our group has pioneered a techique which we call "accelerated ageing". We aim to mimick and accelerate these natural processes in the laboratory in order to avoid the use of toxic and corrosive metal salts, such as metal halides, and directly generate functional metal materials from raw oxides. In an effort to minimize energy input and solvent waste, we generally conduct "self-assembly" reactions using only reactants, high humidity, slight heating (45℃) and occasionally catalysts. We report near quantitative conversions within only a few days. This approach enables us to design syntheses which are scalable, cost-effective, and green. We are currently examining the scope and limitations of this novel technique for synthesizing a variety of metal organic frameworks including zeolitic imidizolate frameworks, as well as separation of metal oxides.