Atom Economy
Atom economy was designed in a different way to all the other metrics; most of these were designed to measure the improvement that had been made. Barry Trost conversely, designed atom economy as a method by which organic chemists would pursue “greener” chemistry. The simple definition of atom economy is a calculation of how much of the reactants remain in the final product. This is shown below:
For a generic multi-stage reaction: A + B → C C + D → E E + F → G
Atom economy = m.w. of G × 100 Σ (m.w. A,B,D,F)
The drawback of atom economy is that assumptions have to be made. For example, inorganic reagents (such as potassium carbonate in a Williamson ether synthesis) are ignored as they are not incorporated into the final product. Also, solvents are ignored, as is the stoichiometry of the reagents.
The atom economy calculation is a very simple representation of the “green-ness” of a reaction as it can be carried out without the need for experimental results. However, it is useful as a low atom economy at the design stage of a reaction prior to entering the laboratory can drive a cleaner synthetic strategy to be formulated.
Read more about this topic: Green Chemistry Metrics
Famous quotes containing the words atom and/or economy:
“Let us build altars to the Blessed Unity which holds nature and souls in perfect solution, and compels every atom to serve an universal end.”
—Ralph Waldo Emerson (1803–1882)
“It enhances our sense of the grand security and serenity of nature to observe the still undisturbed economy and content of the fishes of this century, their happiness a regular fruit of the summer.”
—Henry David Thoreau (1817–1862)