Transition State

The transition state of a chemical reaction is a particular configuration along the reaction coordinate. It is defined as the state corresponding to the highest energy along this reaction coordinate. At this point, assuming a perfectly irreversible reaction, colliding reactant molecules will always go on to form products. It is often marked with the double dagger ‡ symbol. It is also related to enzymes.

As an example, the transition state shown below occurs during the SN2 reaction of bromoethane with a hydroxyl anion.

Read more about Transition State:  History of Concept, Explanation, Observing Transition States, Locating Transition States By Computational Chemistry, The Hammond–Leffler Postulate, The Structure-correlation Principle, Implications For Enzymatic Catalysis

Famous quotes related to transition state:

    Some of the taverns on this road, which were particularly dirty, were plainly in a transition state from the camp to the house.
    Henry David Thoreau (1817–1862)