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Lab I

Lab II

Lab III

Lab IV

Lab V

Lab VI

Lab VII

Lab VIII

Lab IX

Lab X

Lab XI

Lab XII

Lab IX: Nucleophilic Substitution Reactions: Designer Experiment
 
Pre-lab Work

Submit your Designer Lab Plan Worksheet for approval by your Instructor. The plan is due on or before the date given by your Instructor.

As shown in the lab plan worksheet, your plan should include:

  • the overall reaction that you will be doing
  • the purpose or reason for the experiment and/or the chemistry question you want to answer
  • a list of the possible products
  • how you will analyze your products
  • a TPC which includes the amounts of reagents you will be using, all of your expected products, and their theoretical yields.

Pre-lab Questions:
(Please turn in the answers to these questions when you arrive to lab.)

1. Using ChemDraw, show the expected mechanism for the synthesis of your major product in your Designer lab.  (The mechanism should show whether you believe Sn1, Sn2, E1, and/or E2 are predicted for your reaction.)

Question #2 below is not directly related to your Designer Lab…but, it’s a very common type of problem related to solving unknowns, such as the products in your Designer Lab.

This type of problem is known as a roadmap problem or logic problem!
[If you haven’t already done so, I HIGHLY recommend saving the IR Literature Table in the Appendix into today's e-lab. It's a great reference table!]

2. The following information was obtained for an unknown compound:
--The IR showed the following significant peaks:  3089, 2950-2850, 1597, 1498 and 1455 cm-1.
--No precipitate formed with NaI in Acetone or AgNO3 in Ethanol.  The unknown did produce a green flame in the Beilstein Test.
--Mass Spectrum indicates the following significant m/z peaks:
170/172 and 155/157 in 1:1 ratios with small peaks at 91 and 76.

Please explain what each piece of data means and what could be a possible structure for this compound?

Introduction

This lab is intended to be modeled on the Competing Nucleophiles lab done earlier this semester. Each student will be doing her own individual experiment to answer her question about nucleophilic substitution or elimination reactions.

Experimental Work

Objectives:

  • To obtain new information from your designed experiment.
  • To see if your hypothesis, or your predicted outcome of the experiment, is correct.
  • To answer your chemistry question.

Experimental Procedure

Since each student will be performing her own experiment, there are no specific laboratory instructions. Things to keep in mind are:

Post-lab Questions
(Please email me the answers to these questions by 10AM on Weds., July 3rd.)

1. What compounds are present in the reactants and products of your Designer lab?  Please include your analyzed GC/MS data of your reactants and products and give any other data that might support your conclusion about your products (ie-FT-IR, if applicable.)
2. Write a short paragraph summarizing the results of your lab. Determine if your hypothesis is substantiated and explain why or why not.
3. Discuss any unexpected results and state what you would do differently if you were to do this lab again.

Designer Lab Presentation
You will give an oral presentation of your Designer Lab results during the last lab of the semester. For details, please see your Instructor.
 

DESIGNER LAB PLAN WORKSHEET

Here are the chemicals that are available for your Designer Experiment:

Alcohols: 1-heptanol, 2-heptanol, cyclohexanol, 2-methyl-2-hexanol, 1-nonanol, 2-nonanol, 1-methylcyclohexanol, 2-methylcyclohexanol, benzyl alcohol, phenethyl alcohol, sec- phenethyl alcohol, 2,4-dimethyl-3-pentanol, 3-hexanol, 3,3-dimethyl-2-butanol, trans-2-hexen-1-ol

Alkyl Halides: bromocyclopentane, chlorocyclopentane, bromocyclohexane, chlorocyclohexane, iodocyclohexane, 1-chloroheptane, 1-bromoheptane, 1-iodoheptane, 2-bromoheptane, bromomethylcyclohexane, 1-bromo-2-ethylhexane

Acids and Bases: 18M sulfuric acid, 12M hydrochloric acid, 15M phosphoric acid, glacial (100%) acetic acid, 12M potassium hydroxide, saturated sodium bicarbonate

Salts and Drying Agents: ammonium chloride, ammonium bromide, ammonium iodide (Do not mix this with sulfuric acid!), potassium acetate, sodium bromide, sodium chloride, sodium iodide (Don't mix with sulfuric acid!), anhydrous magnesium sulfate, silver nitrate in ethanol, sodium ethoxide in ethanol

Solvents: dimethylformide [DMF] (a polar organic aprotic solvent), tetrahydrofuran [THF] (another polar organic aprotic solvent), water, acetone, hexanes, methylene chloride, diethyl ether, ethanol, methanol

**NOTE: Do not mix ammonium iodide or sodium iodide with sulfuric acid!!!**

**If you wish to order a chemical NOT on the list of chemicals above,
please contact your instructor immediately!**

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Designer Lab Proposal Form:

Please model your procedure after the Competing Nucleophiles Lab. This must be a synthetic reaction!! Do not do a test tube lab as was done in the Alkyl Halide lab!!

Name:

Lab day:

Question to be answered:

 


Prediction/Hypothesis:

 



Equation for expected reaction (use ChemDraw to write your reaction):

 



Predicted Major product (Show ChemDraw structure):

 


 
Predicted Minor product(s) (Show ChemDraw structures):

 



Do you expect the reaction to go SN1__ SN2___ Elimination___ Other___ (explain):

 

Instruments to be used to analyze my product:

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One day after your proposal is accepted by your instructor, please email your instructor your TPC
with the appropriate amounts of each reactant, their chemical properties, and theoretical yield, if applicable.

(Use similar molar quantities as in the
Competing Nucleophiles or the Dehydration Labs.)

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