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SN2 reaction is a basic reaction type in organic chemistry. The letter S<sub>N</sub> stand for nulceophilic Substitution, the number 2 stands for bimolecular. This means that both reactions partners are involved in the reaction rate determining step. It also exists an S<sub>N</sub>1 reaction; here, only one reaction partner is involved in this step.
==S<sub>N</sub>2-substitution of chloride and methanol==


On the other side, SN2 reactions are characterised for exchanging substituents. The substituent that leaves the molecule is called leaving group.
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== S<sub>N</sub>2-Substitution of chloride and methanol ==
<caption>SN2 - Substitution of Cl&lt;sup>-&lt;/sup> and Methanol</caption>
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Typically, alkanes with a substituent in primary position undergo S<sub>N</sub>2 reactions. In contrast to a S<sub>N</sub>1 reaction, no stable carbo cation can be formed. Therefore, another way will be taken.  
SN2 reaction is a basic reaction type in organic chemistry. The letter S<sub>N</sub> stands for nulceophilic Substitution, the number 2 stands for bimolecular, with both reactions partners are involved in the reaction rate determining step. It also exists an S<sub>N</sub>1 reaction; here, only one reaction partner is involved in this step. On the other side, SN2 reactions are characterized by exchanging substituents. The substituent that leaves the molecule is called leaving group.
The S<sub>N</sub>2 <jmol><jmolLink><script>anim mode once; frame range 1 10; delay 0.5; frame play</script><text>reaction starts</text></jmolLink></jmol> by establishing a so called intermediate state.  This means that both educts come close to each other. By this, the bond of the leaving group is partly broken, and the bond to the new group is partly formed. The formation of this intermediate state is the rate determining step of the reaction.
 
Typically, alkanes with a substituent in primary position undergo S<sub>N</sub>2 reactions. In contrast to a S<sub>N</sub>1 reaction, no stable carbo cation can be formed, therefore, another way is taken.
The S<sub>N</sub>2 <jmol><jmolLink><script>anim mode once; frame range 1 10; delay 0.5; frame play</script><text>reaction starts</text></jmolLink></jmol> by establishing a so called ''intermediate'' state, with both educts comeing close to each other. By this, the bond of the leaving group is partly broken, and the bond to the new group is partly formed. The formation of this intermediate state is the rate determining step of the reaction.
In the <jmol><jmolLink><script>anim mode once; frame range 11 20; delay 0.5; frame play</script><text>second step</text></jmolLink></jmol>, the bond of the leaving group is completely broken, and at the same time the bond to the new substituent is completely formed.
In the <jmol><jmolLink><script>anim mode once; frame range 11 20; delay 0.5; frame play</script><text>second step</text></jmolLink></jmol>, the bond of the leaving group is completely broken, and at the same time the bond to the new substituent is completely formed.
[[Image:reaction_scheme_sn2.jpg|450px]] <br>
The S<sub>N</sub>2 reaction has a very interesting stereochemistry inversion of the stereocenter<ref>PMID: 27505286 </ref> with an animated example of the substitution of chloride and methanol shown. Please click on the buttons below to '''animate''' the reaction with different representations. Use the '''popup''' button to enlarge the view and the '''quality''' button to turn on anti-aliasing.


[[Image:reaction_scheme_sn2.jpg]]
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The S<sub>N</sub>2 reaction has a very interesting stereochemistry.
inversion of the stereocenter...
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The animation was originally done by [[User:Verena Pietzner | Prof. Dr. Verena Pietzner]]; for details, see her web site ChiLe<ref>[http://www.chemieunterricht-interaktiv.de/en/index.html ChiLe Web Site]</ref>. The implementation into Proteopedia was done by [[User:Jaime Prilusky | Prof. Jaime Prilusky]], [[User:Joel L. Sussman | Prof. Joel L. Sussman ]] 
This demo was adapted from http://www.chemieunterricht-interaktiv.de/en/animations/sn2_substitution/sn2_substitution_3d.html by Dr. V. Pietzner, part of the ChiLe project
and [[User:Veronika Pelekhov | Veronika Pelekhov]].


===See also===
[[SN1_reaction|S<sub>N</sub>1 reaction: Substitution of Cl<sup>&minus;</sup> and ''tert''-Butanol ]]<br>
[[Esterification|Esterification]]<br>
[[Ozonolysis|Ozonolysis - a type of cycloaddition]]


===See also===
== References ==
[[SN1_reaction|S<sub>N</sub>1 reaction: Substitution of Cl<sup>&minus;</sup> and ''tert''-Butanol ]]
<references/>

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Jaime Prilusky, Verena Pietzner, Angel Herraez, Joel L. Sussman