Nucleophilic Substitution
Lab Report: Nucleophilic substitution reaction
Introduction:
Alkyl halides undergo many reactions in which a nucleophile displaces the halogen atom bonded to the central carbon of the molecule. The displaced halogen atom becomes a halide ion.
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Some typical nucleophiles are the hydroxy group (−OH), the alkoxy group (RO−), and the cyanide ion (−C N). Reaction of these nucleophiles with an alkyl halide (R—X) gives the following reactions and products:
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The halogen ion that is displaced from the carbon atom is called the leaving group, and the overall reaction is called a nucleophilic substitution reaction.
Procedure:
1. Sodium Iodide in Acetone.
Acetone, with a dielectric constant of 21, is a relatively nonpolar solvent that will readily dissolve sodium iodide. The iodide ion is an excellent nucleophile, and the nonpolar solvent, acetone, favors the Sn2 reactions; it does not favor ionization of the alkyl halide. The extent of reaction can be observed because sodium bromide and sodium chloride are not soluble in acetone and precipitate from solution if reaction occurs.
2. Ethanolic Silver Nitrate Solution.
Label eleven small containers and place 0.1 mL or 100 mg of each of the following halides in the tubes: 1-chlorobutane, 2-chlorobutane, 2-chloro-2-methylpropane, 1-bromobutane, 2-bromobutane, 2-chloro-2butene, Iodoethane, 1-Chloroadamantane, Bromobenzene, 1-chloro-2-butene, 1-chloro-2-methylpropane. To each tube rapidly add 1mL of an 18% solution of sodium iodide in acetone.
Repeat the procedure with 1% ethanolic silver nitrate solution.
Data/Results:
Name | Sodium Iodide | Silver Nitrate | 1-Chloroadamantane | Ppt at room temperature | Ppt at room temperature | 2-chlorobutane | Ppt in the hot plate | No ppt | 1-chloro-2-butene | Ppt at room temperature | Ppt | Bromobenzene | Ppt | Ppt | 2-bromobutane | Ppt at room temperature | Ppt at room temperature | 2-chloro-2-methylpropane | Yellow
Introduction:
Alkyl halides undergo many reactions in which a nucleophile displaces the halogen atom bonded to the central carbon of the molecule. The displaced halogen atom becomes a halide ion.
| | | |
Some typical nucleophiles are the hydroxy group (−OH), the alkoxy group (RO−), and the cyanide ion (−C N). Reaction of these nucleophiles with an alkyl halide (R—X) gives the following reactions and products:
| | | |
The halogen ion that is displaced from the carbon atom is called the leaving group, and the overall reaction is called a nucleophilic substitution reaction.
Procedure:
1. Sodium Iodide in Acetone.
Acetone, with a dielectric constant of 21, is a relatively nonpolar solvent that will readily dissolve sodium iodide. The iodide ion is an excellent nucleophile, and the nonpolar solvent, acetone, favors the Sn2 reactions; it does not favor ionization of the alkyl halide. The extent of reaction can be observed because sodium bromide and sodium chloride are not soluble in acetone and precipitate from solution if reaction occurs.
2. Ethanolic Silver Nitrate Solution.
Label eleven small containers and place 0.1 mL or 100 mg of each of the following halides in the tubes: 1-chlorobutane, 2-chlorobutane, 2-chloro-2-methylpropane, 1-bromobutane, 2-bromobutane, 2-chloro-2butene, Iodoethane, 1-Chloroadamantane, Bromobenzene, 1-chloro-2-butene, 1-chloro-2-methylpropane. To each tube rapidly add 1mL of an 18% solution of sodium iodide in acetone.
Repeat the procedure with 1% ethanolic silver nitrate solution.
Data/Results:
Name | Sodium Iodide | Silver Nitrate | 1-Chloroadamantane | Ppt at room temperature | Ppt at room temperature | 2-chlorobutane | Ppt in the hot plate | No ppt | 1-chloro-2-butene | Ppt at room temperature | Ppt | Bromobenzene | Ppt | Ppt | 2-bromobutane | Ppt at room temperature | Ppt at room temperature | 2-chloro-2-methylpropane | Yellow