CHEM 2311 Organic Chemistry Laboratory Fall Semester, 2002

Transcription

1 CHEM 2311 Organic Chemistry Laboratory Fall Semester, 2002 INSTRUCTOR: Dr. Jane E. Wissinger, 461 Kolthoff, , Website: OFFICE HOURS: Monday, Wednesday, 10:10-11:10 a.m. and by appointment. REQURIED MATERIALS: Donald L. Pavia, Gary M. Lampman, George S. Kriz, and Randall G. Engel, Microscale and Macroscale Techniques in the Organic Laboratory, Harcourt College Publishers, New York, Jane E. Wissinger, Laboratory Manual for Organic Chemistry 2311, Thomson Learning Custom Publishing, LECTURES: 11:15 a.m.-12:05 p.m. & 12:20 p.m.-1:10 p.m. (Science Classroom Building 375) PREREQUISITES: The 2311 course is to be taken following the lecture course, 2301, and concurrently with or subsequent to lecture course Welcome to Organic Chemistry Laboratory This course is an introduction to the tools and techniques required for the isolation, purification, separation, and identification of organic compounds. Principles learned in the 2301 and 2302 lecture courses will be illustrated while teaching chemistry related to everyday life. You will be exposed to questions involving stereochemistry, thermodynamics, kinetics, catalysis, and computational chemistry. Hands-on experience with Infrared Spectroscopy and Gas Chromatography will be provided and selected product samples will be submitted for 200 MHz 1 H NMR analysis. You will be evaluated both on your knowledge of the chemistry of the experiments and your technical skills on the bench. TIPS FOR SUCCESS 1) Attend lab lecture. The theory and purpose of each experiment will be discussed along with a discussion and demonstration of new techniques. 2) Come prepared to lab! This is probably the most important thing you can do with respect to safety for yourself and others, in addition to preparing yourself to work efficiently and effectively. Your lab notebook will checked to assure that you have an outline of the procedure to be followed and that you understand all hazards. You ll find good experimental results will follow. 3) Think about what is happening during the lab. There is a reason for every observation and every step in a procedure. Learning how to independently interpret and react to experimental observations is key to success in scientific discovery. 4) Work carefully; mistakes are often irreversible. 5) Work efficiently. Frequently, you can do two or more things at the same time multi-tasking. If your work is planned and you are thinking and trying to work efficiently, you need not be rushed, even for the longer labs. SAFETY The safety practices outlined on pages 4-21 of the Pavia textbook and on page 9 of the Laboratory manual should be read before beginning the first experiment and reviewed frequently throughout the semester. Note that Minnesota state law requires that safety goggles must be worn at all times when you are in the laboratory. TA s are authorized to expel students from the laboratory who fail to obey this or other safety rules. WASTE DISPOSAL It is extremely important that all chemicals be disposed of in the proper manner according to the Waste Disposal guides that will be posted and given to you in lab. Mixing of incompatible materials can cause fires and even explosions. Mercury spills in the laboratory are of special concern and must be cleaned up with a designated kit from stockroom personnel. 1

2 EQUIPMENT AND CHEMICALS Many experiments require special equipment and chemicals to be checked out from the stockroom. Amounts of some chemicals are controlled. Please use the vials you get from the stockroom to turn in your synthetic products. Do not remove reagent and solvent bottles from their central location! Violation of this rule is unfair to your classmates and you may be punished. Cleanliness in the classroom is of paramount importance. A considerable part of your grade is subjective, and dirty equipment and leaving spilled chemicals is both hazardous and gives a bad impression, which will hurt your grade. All items checked out from the stockroom must be returned to the stockroom on the same day, unless you are given specific instruction to do otherwise. Many of the items are in short supply. NOTEBOOK Scientific work can be no better than the records that are kept of it. Consequently, you are required to keep a bound notebook as specifically described on pages of the Pavia text. Prior to the experiment, the lab notebook is used to document important data related to the chemicals used, expected products and by-products, and to write an outline of the procedure that will be followed. Then during the experiment the notebook is used to record quantities measured, all observations, and any modifications of the operations carried out. All notes are to taken in blue or black ink (never pencil) and directly in the notebook, NEVER on extraneous scrapes of paper. Date all entries and keep a table of contents. Neatness is desirable, but it is less important than having a notebook that is accurate and complete. GRADING POLICY Criteria, which will be used in evaluating student performance in the laboratory, are: (1) Worksheets 750 pts (2) Full Reports 750 pts (3) Preparation/Technique Grade (20 x 20 pts) 400 pts (4) *Quizzes (5 x 40 pts) 200 pts Total 2100 pts *Quizzes will be given at the beginning of the laboratory period on the following dates: Quiz 1 9/18, 9/19 (Week 3), Quiz 2-10/9, 10/10 (Week 6), Quiz 3 10/30, 10/31 (Week 9), Quiz 4 11/20, 11/21 (Week 12), Quiz 5 12/4, 12/5 (Week 14) The TA for your section will turn in number and letter grades to me. By consultation, these will be adjusted to achieve consistency between sections. Ultimately, I will make the final grade decision. WORKSHEETS AND REPORTS The results of the experiments will be reported on worksheets or in the format of a scientific report. ALL worksheets and reports are to be turned in on the designated day or points (5 pts/day) will be deducted. No Exceptions Without Written Documentation and Approval Of the Instructor! The 100 point reports should be 2-4 pages in length, not including spectra, and should be written in the following format: Report Format: 1. Title. 2. Purpose: Give a brief statement of the objective of the experiment. For labs involving synthesis of a compound, draw the reaction sequence. 3. Procedure: Reference the procedure followed and state any significant deviations that would impact the outcome of the experiment. 4. Results and Observations: Present your data and results as clear and concisely as possible. Tables are often very useful here. For the synthesis of a product, record the actual yield (in grams), the percent yield, and the physical properties (e.g., color, m.p., b.p., spectra) of the product. Reference any literature data used for comparison. 2

3 5. Discussion and Conclusions. Summarize the results obtained with respect to the purpose of the experiment (learning a new technique, demonstrating a principal, or synthesizing a compound). Discuss any sources of error or improvements that could be made. Answer any questions or present mechanisms required by your TA. 6. Appendix According to TA instructions, include relevant calculations, tables of spectral data, etc.. PRODUCTS Products will be collected for many experiments. They should be turned in to your TA at the end of the laboratory period to receive full credit. Weigh the vial (or bottle) before introducing your compound and record this "tare" weight on the label. The tare weight is generally taken exclusive of the stopper or cap. A label should be printed neatly in ink and securely attached to the vial. It is absolutely essential that your name and the compound name is on the label. If a product vial is found without a label, it must be handled as an unknown hazardous material, which is very costly for all of us! A sample label follows: n-butyl Bromide b.p C Yield 25.5 g (Tare 48.5 g) John Adams TAs will grade your product based on purity, color, crystallinity and melting point (for solids), as well as spectral data, when available. They will also check that masses are accurately reported. MAKE-UP POLICY Missed experiments can be made-up only for valid reasons (e.g. documented illness or family emergency) and by arrangement with your TA, with my approval. Several make-up days are scheduled throughout the quarter and are to be used to complete any experiment missed up to that point. In some cases, you will be able to make-up an experiment earlier during a lab period with a shorter experiment. CONDUCT AND DISCIPLINE Scholastic Dishonesty- The Institute of Technology expects the highest standards of honesty and integrity in the academic performance of its students. Any act of scholastic dishonesty is regarded as a serious offense, which may result in expulsion. The Institute of Technology defines scholastic dishonesty as submission of false records of academic achievement; cheating on assignments or examinations; plagiarizing; altering, forging, or misusing an academic record; taking, acquiring, or using test materials without faculty permission; and acting alone or in cooperation with another to obtain dishonestly grades, honors, awards, or professional endorsement. Aiding and abetting an act of scholastic dishonesty is also considered a serious offense. In summary, copying reports or falsifying data will not be tolerated in this course. Also, altering a report or worksheet and then submitting it for a re-grade is also an act of scholastic dishonesty. Through the semester you are asked to work in pairs from time to time. It is expected that you will share the data, but all interpretation should be your own. Finally, using graded work from a student who took this course in a previous semester is considered falsifying data. If a student is guilty of scholastic dishonesty, they will receive no credit for the work involved, and the incident will be reported to the college s Scholastic Conduct Committee where it is kept on file. 3

4 CHEM 2311 Fall Semester 2002 SEQUENCE OF EXPERIMENTS AND READING ASSIGNMENTS Date Experiment, New Techniques Reading M T W TH and Essays Pavia, Manual 9/03 9/04 Check-in Chapters 1-3 (Intro, Notebooks, Safety) 1-41, /04 9/05 Analysis of Analgesics by Thin-Layer Chromatography 13 Chapter 20 (Thin-Layer Chromatography) Chapter 10 (Solubility) Essays Aspirin and Analgesics /09 9/10 Separation of Ferrocene/Acetylferrocene by Column Chromatography Chapter 19 (Column Chromatography) Chapters 4-5 (Chemical data, measurements) Chapter 9 (Physical Constants of Solids: The Melting Point) /11 9/12 Nucleophilic Substitution Reactions of Alkyl Halides /16 9/17 Synthesis of t-butyl Chloride Calculation of Yields Chapter 15 (Simple Distillation - macroscale) Chapter 12 (Extractions, Separations, and Drying Agents) , /18 9/19 Separation of the Components of an Analgesic Tablet (Pairs) Chapter 12 (Extraction Macroscale/Acid/Base) , , Chapter 11 (Crystallization) , , Chapter 8 (Filtrations) Essays Aspirin and Analgesics /23 9/24 Make-up 9/25 9/26 1 H NMR Analysis of a Solvent Mixture Chapter 26 (Nuclear Magnetic Resonance Spectroscopy) /30 10/01 Grignard Synthesis of Triphenylmethanol from Benzophenone /02 10/03 Anhydrous reaction conditions, extraction, drying, crystallization. 10/07 10/08 Synthesis of Isopentyl Acetate (Banana Oil) Chapter 25 (Infrared Spectroscopy) 11, Reflux, extraction, distillation, IR, NMR of product Essays Esters Flavors and Fragrances and Stereochemical Theory of Odor 10/09 10/10 Tetraphenylcyclopentadienone on a Microscale Comparison of Reaction Conditions. Aldol Condensation (Wade p ) Chapter 11 (Crystallization Microscale w/o Craig tube) 10/14 10/15 The Diels-Alder Reaction: Preparation of ,2,3,4-Tetraphenylnaphthalene on a Microscale Essay Diels-Alder Reaction and Insecticides

5 CHEM 2311 Spring Semester 2002, Page 2 SEQUENCE OF EXPERIMENTS AND READING ASSIGNMENTS Date Experiment, New Techniques Reading M T W TH and Essays Pavia, Manual 10/16 10/17 The Chemistry of Dyes and Fabrics: Preparation of Orange II and Methyl Orange Essays Synthetic Dyes and Dyes and Fabrics /2110/22 10/2310/24 Molecular Mechanics and Computational Chemistry Chapter 29 (Computational Chemistry) , /2810/29 10/3010/31 Nitration of Methyl Benzoate Electrophilic Aromatic Substitution Reaction Chapter 12 (Microscale Extraction) /2810/29 10/3010/31 Dehydration Reaction of 2-Methyl-2-butanol (Pairs) Chapter 22 (Gas Chromatography) All procedures should be done in the hood! 11/4 11/5 11/6 11/7 Friedel-Crafts Alkylation of m-xylene + Computational Analysis Chapter 25/14 (IR of Aromatic Rings) Microscale extraction, filtrations, computational chemistry, GC Make-up 11/11 11/12 Polymer Structures and Reactions: Recycling a Plastic Beverage Bottle Essay Polymers and Plastics Students supply 3 g clear, plastic from a PET bottle, cut into 10 mm squares 11/13 11/14 Oxidation and Reduction Reactions of Camphor Natural Products /18 11/19 Chapter 17 (Sublimation) Essays Terpenes and Phenylpropanoids and Reduction of Camphor with Sodium Borohydride 11/20 11/21 Thermodynamic versus Kinetic Formation of Semicarbazones (Pairs) /25 11/25 (melting points) Holiday Break 12/2 12/03 Catalytic Hydrogenation of Eugenol Essays Terpenes and Phenylpropanoids /04 12/05 Luminol and Chemiluminescence Essays Fireflies and Photochemistry and Luminol /09 12/10 Make-up 12/11 12/12 Checkout 5

6 2311 Schedule of Experiments and Due Dates of Worksheets/Reports Fall Semester 2002 Week Pts Experiment Worksheet Report Instruments 1 Check-in 1 50 TLC Chromatography 9/11, 9/ *Ferrocene/Acetylferrocene 9/16, 9/ Substitution Reactions of Alkyl Halides 9/18, 9/ Synthesis of t-butyl Chloride 9/25, 9/ *Separation of Analgesics (Pairs) 9/30, 10/1 4 Make-up 4 50 NMR Analysis of a Solvent Mixture 10/2, 10/ *Grignard Synthesis of Ph 3 COH 5 Grignard Synthesis, cont d 10/9, 10/ Banana Oil 10/16, 10/17 IR, NMR 6 50 Tetraphenylcyclopentadienone 10/21, 10/ *1,2,3,4-Tetraphenylnaphthalene (Diels-Alder) 10/23, 10/24 NMR Orange II and Methyl Orange Dyes 10/28, 10/ Computational Chemistry 11/4, 11/5 CC 9 50 Dehydration of 2-Methyl-2-butanol (Pairs) 11/6, 11/7 GC (NMR) *Nitration of Methyl Benzoate 11/11, 11/12 IR, NMR Friedel-Crafts Alkylation of m-xylene 11/18, 11/19 IR, CC, (GC) 10 Make-up + CC work Recycling Plastics 11/20, 11/ *Oxidation/Reduction Camphor Cmpds 12 *Oxidation/Reduction, cont d 12/2, 12/3 IR, NMR, (CC) Semicarbazone (Pairs) 12/4, 12/5 13 Semicarbazone, melting points 13 Thanksgiving Holiday Catalytic Hydrogenation of Eugenol 12/11, 12/12 NMR *Luminol 12/11, 12/12 15 Make-up 15 Check-out * Products collected Bold numbers indicate quiz dates. 6