A University of Toronto research team from the Department of Chemistry has discovered efficient "green" catalysts composed of the metal iron, which may replace the more expensive and toxic metal platinum.
A University of Toronto research team from the Department of Chemistry has discovered efficient "green" catalysts composed of the metal iron, which may replace the more expensive and toxic metal platinum, which is often used in industrial chemical processes to make drugs, fragrances and flavorings.
The preparation of drugs often relies on the use of catalysts, and the cost of these affects the final price of the drug. If the catalyst is toxic, like most metals of the platinum series - ruthenium, rhodium and palladium, it must be completely removed in the final stage of the synthesis using expensive cleaning methods. "By using a less toxic catalyst, such as iron, these disadvantages are avoided," says Professor Robert Morris.
The successful use of iron as a catalyst, instead of the more common metal ruthenium, is surprising because iron is considered a "basic" metal with low catalytic activity. The successful ploy was to prepare an iron conjugate with a structure similar to the most active ruthenium catalyst, explains the researcher.
Catalysts are known to have the ability to speed up a chemical reaction, but they are also able to affect the final structure of the reaction product, the researcher notes. Effective catalysts are those that allow selective acceptance of only one of the desired structures of the final product (a certain enantiomer and not another).
The catalyst was prepared by connecting an organic compound containing carbon, hydrogen, phosphorus and nitrogen atoms and existing in a certain isomeric form (the "right" enantiomer) to the iron atom. A small amount of the catalyst enables the conversion of large quantities of the cheap substance ketone into large quantities of the polyalcohol product its corresponding value as the right enantiomer only. This process is called asymmetric hydrogenation.
The results of the research appear in the scientific journal Chemistry - A European Journal.
