A recent paper in Science reports just that. By trapping a transition metal catalyst in a tetrahedral supramolecular cage, researchers at the Lawrence Berkeley National Laboratory have been able to create a functional enzyme mimic, dramatically increasing reaction rates for production of ethane from dialkyl-metal complexes, in some cases by 80,000 times. This is the kind of catalytic efficiency associated with nature’s enzymes. The authors point out that nature’s catalysts have a scope limited by the requirements of living creatures. Applying this principle to purely technical reactions ought to open up new areas unexplored by nature. As the authors write “This wedding of biomimetic and anthropogenic chemistry opens the door for a paradigmatic shift in strategic approaches to catalysis”.
The tetrahedral complex that achieves this feat is a gallium complex with N,N’-bis(2,3-dihydroxybezoyl)-1,5-diamino naphthalene. It self-assembles, as nature's enzyme complexes do, and within its hydrophobic interior it encapsulates cationic transition metal complexes.
This work is a great leap forward in matching nature’s catalytic virtuosity using self-assembled supramolecular structures. Richard Feynman would have been delighted to witness it.
Science, 4 December 2015, pp. 1235-38.