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 StateHistory of Concept, Explanation, Observing Transition States, Locating Transition States By Computational Chemistry, The Hammond–Leffler Postulate, The Structure-correlation Principle, Implications For Enzymatic Catalysis

Other articles related to "transition state, transition states, transition":

Migratory Insertion - Insertion of Alkenes Into Metal-carbon Bonds - Mechanism
... of olefin insertions include the formation of the cyclic, planar, four-center transition state involving incipient formation of a bond between the metal and an ... From this transition state, it can be seen that a partial positive charge forms on the β-carbon with a partial negative charge formed on the carbon initially bonded to the metal ... This transition state also highlights the two factors that most strongly contribute to the rate of olefin insertion reactions (i) orbital overlap of the alkyl group initially attached to the metal and (ii) the ...
Aromatic Transition State Theory
... The Aromatic transition state theory assumes that the minimum energy transition state for a pericyclic process must be aromatic ... For 4n+2 π sysyems (2,6,10...) Huckel transition states are proposed where the molecule is flat ... In 4n π sysyems (4,8,12...) Mobius transition states are proposed which involve a twist or require a node to be aromatic ...
More O'Ferrall-Jencks Plot - Applications - Elimination Reactions
... Thus, the transition state moves towards the reactants and away from the carbanion intermediate ... model does not predict any change in leaving group departure at the transition state ... The true change predicts more carbocation character at the transition state and a mechanism that is more E1-like ...
Chorismate Mutase - Mechanism of Catalysis
... As a result there is no formal intermediate, but rather a chair-like transition state ... of the flexible substrate, specific hydrogen bonding to the transition state, and electrostatic interactions actually contribute to catalysis ... between it and the negatively charged transition state promoted catalysis ...
Transition State - Implications For Enzymatic Catalysis
... catalysis proceeds is by stabilizing the transition state through electrostatics ... By lowering the energy of the transition state, it allows a greater population of the starting material to attain the energy needed to overcome the transition energy and proceed ...

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