HO − + CH 3 Cl CH 3 OH + Cl −
H 3 N ++CH 3 Br CH 3 NH+ 3 Br −
- Nucleophilic substitution reactions where the substarte bears a formal positive
charge:
Nu + R L+ R Nu+ + L
Specific Example:
H 3 CO
H
H 3 CO
H
+ H 3 C O + CH
H
+ H O H
H
3 +
6.6 KINETICS OF A NUCLEOPHILIC SUBSTITUTION REACTION:
AN SN 2 REACTION
- Kinetics: the relationship between reaction rate and reagent concentration
- The reaction between methyl chloride and hydroxide ion in aqueous solution:
60 oC
HO H 2 O
− + CH 3 Cl CH 3 OH + Cl −
Table 6.3 Rate Study of Reaction of CHCl 3 with OH– at 60 °C
Experimental
Number
Initial
[CH 3 Cl]
Initial
[OH–]
Initial
(mol L–1 s–1)
1 0.0010 1.0 4.9 × 10–7
2 0.0020 1.0 9.8 × 10–7
3 0.0010 2.0 9.8 × 10–7
4 0.0020 2.0 19.6 × 10–7
1) The rate of the reaction can be determined experimentally by measuring the rate
at which methyl chloride or hydroxide ion disappears from the solution, or the