Atom economy

Atom economy

Atom economy (atom efficiency) describes the conversion efficiency of a chemical process in terms of all atoms involved. In an ideal chemical process the amount of starting materials or reactants equals the amount of all products generated (see stoichiometry) and no atom is wasted. Recent developments like high raw material (such as petrochemicals) costs and increased sensitivity to environmental concerns have made atom economical approaches more popular. Atom economy is an important concept of green chemistry philosophy [cite journal
title = Atom Economy. A Challenge for Organic Synthesis
author = Trost B. M.
journal = Angew. Chem. Int. Ed. Engl.
volume = 34
issue = 3
pages = 259–281
year = 1995
doi = 10.1002/anie.199502591
]

[cite journal
title = Atom efficiency and catalysis in organic synthesis
author = Sheldon R. A.
journal = Pure and Applied Chemistry
volume = 72
issue = 7
pages = 1233–1246
year = 2000
url = http://www.iupac.org/publications/pac/2000/7207/7207pdf/7207sheldon_1233.pdf
doi = 10.1351/pac200072071233
] [ [http://www.chemsoc.org/pdf/gcn/atomeff.ppt Atom Economy: A Green Chemistry Module] ] .

Atom economy can be written as:

% atom economy = frac{Molecular ,Weight ,of, desired ,product}{Molecular ,Weight ,of, all ,reactants} imes 100%

Note that atom economy can be poor even when chemical yield is near 100%, see for instance the Cannizzaro reaction. A Diels-Alder reaction is an example of a potentially very atom efficient reaction.On the other hand if the desired product has an enantiomer the reaction needs to be sufficiently stereoselective even when atom economy is 100%.

Atom economy can also be adjusted if a pendant group is recoverable, for example Evans auxiliary groups. However, if this can be avoided it is more desirable, as recovery processes will never be 100%. Atom economy can be improved upon by careful selection of starting materials and a catalyst system.

Atom economy is just one way to evaluate a chemical process. Other criteria can include energy consumption, pollutants released and price.

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Lithium economy — The lithium economy is a concept analogous to the hydrogen economy, methanol economy, ethanol economy, electron economy, vegetable oil economy, or liquid nitrogen economy but where the energy vector is lithium. Analogous economies are the zinc… …   Wikipedia

  • The Clockwork Atom Bomb — Infobox short story name = The Clockwork Atom Bomb author = Dominic Green country = United Kingdom language = English series = genre = Science fiction short story published in = Interzone publication type = Periodical publisher = media type =… …   Wikipedia

  • Nuclear Explosions for the National Economy — (sometimes referred to as Program #7[1]), was a Soviet program to investigate peaceful nuclear explosions (PNEs). It was analogous to the US program Operation Plowshare. One of the better known tests was Chagan of January 15, 1965. Radioactivity… …   Wikipedia

  • Japan and the World Economy — Infobox Journal title = Japan and the World Economy editor = Robert Dekle Yasushi Hamao discipline = economics language = english abbreviation = Jpn World Econ publisher = Elsevier, North Holland imprint country = Amsterdam frequency = 4 times a… …   Wikipedia

  • MHE — municipal housing economy. Термины атомной энергетики. Концерн Росэнергоатом, 2010 …   Термины атомной энергетики

  • Green Chemistry Metrics — Having made a “Green Chemistry” improvement to a chemical process, it is important to be able to quantify the change. By quantifying the improvement, there is a tangible element or benefit from the new technology introduced. This is likely to aid …   Wikipedia

  • Chemical reaction — Chemical reactions redirects here. For the 2007 television episode, see Chemical Reactions (Men in Trees). A thermite reaction using iron(III) oxide. The sparks …   Wikipedia

  • Chemische Reaktion — Thermitreaktion Eine chemische Reaktion ist ein Vorgang, bei dem eine oder meist mehrere chemische Verbindungen in andere umgewandelt werden. Auch Elemente können an Reaktionen beteiligt sein. Chemische Reaktionen sind in der Regel mit… …   Deutsch Wikipedia

  • Atomökonomie — und chemische Umwandlungen Die Atomökonomie (auch Atomeffizienz) ist der prozentuale Anteil der in einer chemischen Reaktion von den Edukten in die Produkte überführten Atome. Inhaltsverzeichnis …   Deutsch Wikipedia

  • Cannizzaro reaction — The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction that involves the base induced disproportionation of an aldehyde lacking a hydrogen atom in the alpha position. [cite journal author = Cannizzaro, S …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”