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Organic Reaction Mechanisms

  1. William J le Noble

Published Online: 19 APR 2001

DOI: 10.1038/npg.els.0000614



How to Cite

le Noble, W. J. 2001. Organic Reaction Mechanisms. eLS. .

Author Information

  1. State University of New York, Stony Brook, New York, USA

Publication History

  1. Published Online: 19 APR 2001


The mechanism of a reaction is a pathway by which the atoms travel from their initial positions in the reactants to the final ones in the products; of all the possible pathways, the one followed by most of the molecules in a sample is that which requires the smallest rise in free energy along the way. Reactions are called stepwise if they involve intermediate species with a finite lifetime, or concerted if they do not.


  • chemical kinetics;
  • reactive intermediates;
  • resonance;
  • stereochemistry;
  • transition states;
  • tunnelling