5.33

Advanced Chemical Experimentation

Volume 17 Fall 2002

Spectroscopy

1. Molecular Spectroscopy of Acetylene 2. Magnetic Resonance Spectroscopy & ESR Spectroscopy3. Time-Resolved Spectroscopy

4. Nitrogen Scission by a Molybdenum(III) Xylidene Complex

Faculty and Staff Prof. Andrei Tokmakoff Dr. Mircea D. Gheorghiu

Faculty in charge of 5.33

Laboratory Director

DON’T PANIC

2

Table of Contents Section 1. INTRODUCTION TO THE LABORATORY

1.1 5.33 Roadmap 1.2 First and Last Day in the Lab

A. Check-in B. Check-out C. Charges

1.3 Lecture and Conference Schedule 1.4 The Laboratory Organization and Schedule

A. Experiments B. Laboratory partners C. Working hours D. Returnable equipment E. 5.33 Laboratory schedule

1.5 Standards for Academic Honesty 1.6 Oral Reports, Written Reports, and Posters

A. Oral Reports B. Poster Presentation C. Written Reports

1.7 Notebooks 1.8 Books 1.9 Grading and expectations

A. Grading B. Preparation C. Late work

1.10 Sundry other matters

Section 2. HAZARDOUS CHEMICALS, SAFETY, AND CHEMICAL WASTE

2.1. Safety 2.2. General Safety rules for the Undergraduate Chemistry Laboratories

A. Safety equipment B. Safety Rules and Guidelines

2.3 Environmental Consequences of Laboratory Operation 2.4 Procedures for Handling Hazardous Chemical Wastes

Appendix 2.1: Chemicals Used in Laboratory Appendix 2.2: Waste Inventory Sheets for Experiments 1-4

Experiment 1: MOLECULAR SPECTROSCOPY OF ACETYLENE

IR-Appendix 1: Group Theory IR-Appendix 2: Calculation of Vibrational Frequencies Experiment 2A: MAGNETIC RESONANCE SPECTROSCOPY Experiment 2B: ELECTRON SPIN RESONANCE SPECTROSCOPY

ESR-Appendix 1: Calculation of Hyperfine Coupling Constants

3

Experiment 3: TIME-RESOLVED SPECTROSCOPY Laser-Appendix 1: Two Coupled Oscillators Laser-Appendix 2: Calculation of R0 from Spectral Overlap

Laser-Appendix 3: Convolution Experiment 4: NITROGEN SCISSION BY A MOLYBDENUM(III) XYLIDENE

COMPLEX Appendix A. Fourier Transform Principles and Practice Appendix B. A Few Topics in Data Analysis Appendix C. Desk Inventory Sheet

Roadmap 1

1. INTRODUCTION TO THE LABORATORY

1.1 5.33 Roadmap Welcome to the final, and culminating experience in your formal chemistry laboratory instruction at M.I.T. This subject, 5.33, is intended to synthesize a number of concepts you have encountered in lecture subjects, introduce you to techniques and procedures not encountered in earlier laboratory subjects, and in addition stimulate you to think about the following ideas: ☺ Spectroscopy is more than group frequencies and chemical shifts. You will analyze a spectrum at high resolution to obtain structural information about a molecule, use intensity data to determine relative populations of species, relate line widths to lifetimes, perform ultrafast spectroscopic measurements in the time domain, and find out how optical properties of simple molecules are changing the world in which you live. References: Experiments 1, 2, and 3 Quantum mechanics is good for something. You will use computational chemistry to predict or verify quantities that you measure in the laboratory. References: Experiment 1, Appendix B; Experiment 2B Laboratory safety and proper waste disposal are necessary but not sufficient. In your laboratory work, you should always strive to reduce or eliminate the use or generation of hazardous substances in the design, synthesis, use, and disposal of chemical substances. References: Section 2, Experiment 4 Outline and Organization A. Safety Lecture: A lecture will be given concerning Safety and General

Laboratory Procedures on WEDNESDAY, SEPTEMBER 4.

This lecture is mandatory for all students intending to take this subject. B. Check in: Check-in to your laboratory cabinets will begin following this lecture,

at 3:30 p.m. See: Subsections 1.2 of the Introduction. C. 5.33 Lectures will be held on Tuesdays and Thursdays at 10 a.m.

See: “Lecture and Conference Schedule”, Section 1.3.

Roadmap 2

D. Laboratory conferences to introduce the experiments on which you are working will be held with each group on the first day of work for each set of experiments.

E. Hours: The 5.33 Laboratory is open to students between 12:30 p.m. and 5 p.m.,

Monday through Friday, except for designated holidays. See: “5.33 Laboratory Schedule, Fall Semester 2002”, Section 1.4.

Check in&out-1

1.2 First and Last Day in the Lab

A. Check-In Procedure: September 4, 2002. Check the equipment in your cabinet against the list given to you by the teaching assistant. Immediately report any discrepancies to your teaching assistant, who will either give you a replacement slip to be used for obtaining the missing item at the Stockroom or will locate the item for you. If your equipment is in order, sign the check-in sheet and return it to your instructor. Read, sign, and turn in the sheet on laboratory safety. Once you have checked into the laboratory, you are responsible for the items in your desk. At the termination of the course, even if the subject is dropped the following day, it is your responsibility to check-out of the laboratory. B. Check-Out Procedure Check-out will be Tuesday, DECEMBER 11, only. Further instruction will be given later. No laboratory work will be permitted after December 5th. Students who do not check out on time will be checked out by the Office of Laboratory Supplies and charged $35.00 for this service, in addition to the cost of missing items. C. Charges All chemicals and most equipment and supplies which you will need for this subject will be furnished without special fees. However, you must pay for any non-returnable items that you purchase from the stockroom, safety glasses, and “breakage” of any returnable or desk equipment items. You can check-out returnable items from the stockroom as you need them and should return them as soon as you are finished using them so they will be available for others. At the end of the term you will be charged for all items that you have signed out and not returned and for any items missing from your desk. If you are not sure whether an item is returnable or non-returnable, ask before you sign for it from the stockroom. You will be charged for the FULL price of any equipment that is not returned. Some items (e.g., heating mantles, Powerstats, etc.) are tagged with an identification number. This number is recorded by your name when you rent such an time. If you return a similar item with a different number (i.e., somebody else’s), you will NOT receive credit; instead, the student who originally checked it out (and is probably still looking for it) will receive the credit. For your own records, keep the carbon copy of your requisition slips.

Lecture_schedule 1

1.3 Lecture and Conference Schedule During the first six weeks of the subject, we will present a series of lectures on general background and theory relevant to the experiments. Lectures will be held on Tuesdays and Thursdays from 10:00 – 11:00 a.m. A detailed discussion of each experiment will be presented to each laboratory group when they begin the experiment. The schedule for the general lectures and group conferences is given below.

DATE TOPIC (ALL SECTIONS) LABORATORY CONFERENCES

GROUP A GROUP B GROUP C

W Sept 4 SAFETY LECTURE (1 PM) CHECK-IN STARTING 3:30 pm

Th Sept 5 Introduction, Course Organization N2 Scission Laser/IR NMR/ESR

T Sept 10 Classical Description of Spectroscopy

Th Sept 12 Time and Frequency Domain

T Sept 17 Principles for Interpreting Molecular Spectra

Th Sept 19 Vibrational Spectroscopy

T Sept 24 Electronic Spectroscopy

Th Sept 26 Inorganic Chemistry: Nitrogen Scission with Molybdenum Complexes

T Oct 1 Magnetic Resonance: NMR

Th Oct 3 Magnetic Resonance: ESR

Second Rotation:

M Oct 7

Laser/IR NMR/ESR N2 Scission

Th Oct 8

T Oct 10

T Oct 15 Columbus Day Holiday

Lecture_schedule 2

Th Oct 17

T Oct 22

Th Oct 24

T Oct 29

Th Oct 31

T Nov 5

Third Rotation:

W Nov 6

NMR/ESR N2 Scission Laser/IR

Th Nov 7

T Nov 12

Th Nov 14

T Nov 19

T Nov 21

Th Nov 26

Th Nov 28 Thanksgiving Holiday

T Dec 3

Th Dec 5

W Dec 11 Check Out

Lab_schedule 1

1.4 The Laboratory Organization and Schedule

A. Experiments There are four experiments in Chemistry 5.33. Completion of all experiments is required. Expt. No. Experiment 1 Molecular Spectroscopy of Acetylene 2 Magnetic Resonance Spectroscopy & ESR Spectroscopy 3 Time-Resolved Spectroscopy 4 Nitrogen Scission by a Molybdenum(III) Xylidene Complex B. Laboratory Partners All experiments will be done in groups of three students.

The importance of having lab partners with whom you can work compatibly and communicate conveniently cannot be overemphasized.

Before leaving the Organizational lecture on Wednesday, September 4, you will have found two lab partners and told us their names. During check-in you will be assigned a desk and a schedule for doing the experiments as scheduled. You will be asked for the names of the other students who will form your group. Be sure there is not a conflict in your schedules for working together on the spectroscopy experiments. Note: If you are concurrently taking 5.61, sign up for rotation Group C. This group will do the spectroscopy experiments, which heavily rely on 5.61 material, last. The term is divided into three parts. The students in 5.33 are divided into three Groups, viz., A, B, and C, to work through the semester in the laboratory. During each part you will do experiments according to the schedule on the following pages. An Oral Report schedule is included with the Lab Schedule. Experiment 1, 2, 3 & 4 will require that you sign up in advance with the TAs to use the analytical instruments, computer and glove box. Your cooperation in arranging efficient use of the available facilities in consultation with the TAs is urged.

Sign-up sheets for all instrumentation will be posted regularly on the bulletin board outside the NMR lab

Please help us all to keep things running smoothly by being conscientious in showing up promptly for time when you have signed up (at the beginning of the lab), and by letting the TAs know in advance when you are unable to use time for which you have

Lab_schedule 2

signed up so that someone else can use the instrument. Instrument time for several of the instruments will be very tight; significant abuses of sign-up privileges cannot be tolerated. C. Working Hours Regular lab hours are 12:30 PM until 5 PM, Monday through Friday. The assigned units for 5.33 are 2-13-6, indicating that on the average you should expect to spend the equivalent of three full afternoons a week in the lab. In some experiments more than this amount of time will be needed, and less in others. Allotted time for the work for each three-week part of the term totals 17 lab periods. In some experiments, however, it may be possible for parts of the analysis, calculations, and discussion to be done outside of the lab. The additional six hours a week credit may be regarded as time to be ALLOTTED to reading about the experiments in advance (absolutely essential in 5.33). There will undoubtedly be times when you will want a reaction to proceed during a period other than the scheduled laboratory. This is allowed IF you pick up, read and complete an OVERNIGHT REACTION form. You should also be aware that most equipment seems to have a curious habit of developing high vapor pressure during the night, and will generally have completely evaporated by the following morning. Therefore, if at all possible, you should securely fasten your equipment. Flexible rubber (black) cooling water tubing must be secured to water inlets and condensers with or hose clips, which are available in your desk. D. Returnable Equipment: All equipment checked out for a specific experiment must be returned by the end of that experiment. If this is not done, TAs will adjust your techniques grade on the lab write-up.

Lab_schedule 3

E. 5.33 LABORATORY SCHEDULE FALL SEMESTER 2002

GROUP A

GROUP B

GROUP C

9/4

LABORATORY SAFETY LECTURE 1:00 PM LABORATORY CHECK-IN 3:30 PM

Begin First Rotation 9/5

(#1) NITROGEN (17 DAYS)

(#1) Laser & IR (17 DAYS)

(#1) NMR & ESR

(17 DAYS)

9/6 (#2) (#2) (#2) 9/9 (#3) (#3) (#3) 9/10 (#4) (#4) (#4) 9/11 (#5) (#5) (#5) 9/12 (#6) (#6) (#6) 9/13 (#7) (#7) (#7) 9/16 (#8) (#8) (#8) 9/17 (#9) (#9) (#9) 9/18 (#10) (#10) (#10) 9/19 (#11) (#11) (#11) 9/20 (#12) (#12) (#12) 9/23

Student Holiday

9/24

No 5.33 Lab

9/25 (#13) (#13) (#13) 9/26 (#14) (#14) (#14) 9/27 (#15) (#15) (#15) 9/30 (#16) (#16)

IR Written Report Due (Group B)

Time: 1:10 P.M. Place: in Lab

5.33 Box

(#16)

10/1 (#17) (#17) (#17)

Lab_schedule 4

10/2

Open lab day

10/3 POSTER

PRESENTATION (NITROGEN)

ORAL REPORT

(Laser)

ORAL REPORT

(NMR, ESR)

10/4 POSTER PRESENTATION

(NITROGEN)

ORAL REPORT

(Laser)

ORAL REPORT

(NMR, ESR)

Begin Second Rotation 10/7

(#1) GROUP A Laser & IR (17 DAYS)

(#1) GROUP B

NMR & ESR (17 DAYS)

(#1) GROUP C

NITROGEN (17 DAYS)

10/8 (#2) (#2) (#2) 10/9 (#3) (#3) (#3) 10/10 (#4) (#4) (#4) 10/11 (#5) (#5) (#5) 10/14 10/15

COLUMBUS DAY VACATION

10/16 (#6) (#6) (#6) 10/17 (#7) (#7) (#7) 10/18 (#8) (#8) (#8) 10/21 (#9) (#9) (#9) 10/22 (#10) (#10) (#10) 10/23 (#11) (#11) (#11) 10/24 (#12) (#12) (#12) 10/25 (#13) (#13) (#13) 10/28 (#14) (#14) (#14) 10/29 (#15) (#15) (#15) 10/30 (#16)

IR Written Report Due (Group A) Time: 1:10 P.M.

Place: in Lab 5.33 Box

(#16)

(#16)

10/31 (#17) (#17) (#17) 11/1

Open lab

Lab_schedule 5

11/4 ORAL REPORT

(Laser)

ORAL REPORT

(NMR, ESR)

POSTER PRESENTATION

(NITROGEN)

11/5 ORAL REPORT

(Laser)

ORAL REPORT

(NMR, ESR)

POSTER PRESENTATION

(NITROGEN)

Begin Third Rotation 11/6

(#1) GROUP A

NMR & ESR (17 DAYS)

(#1) GROUP B

NITROGEN (17 DAYS)

(#1) GROUP C Laser & IR (17 DAYS)

11/7 (#2) (#2) (#2) 11/8 (#3) (#3) (#3) 11/11

VETERANS DAY HOLIDAY

11/12

No 5.33 Lab

11/13 (#4) (#4) (#4) 11/14 (#5) (#5) (#5) 11/15 (#6) (#6) (#6) 11/18 (#7) (#7) (#7) 11/19 (#8) (#8) (#8) 11/20 (#9) (#9) (#9) 11/21 (#10) (#10) (#10) 11/22 (#11) (#11) (#11) 11/25 (#12) (#12) (#12) 11/26 (#13) (#13) (#13) 11/27

No 5.33 lab

11/28 11/29

THANKSGIVING VACATION

12/2 (#14) (#14) (#14) 12/3 (#15) (#15) (#15) 12/4 (#16)

(#16) (#16)

IR Written Report Due (Group C)

Time: 1:10 P.M. Place: in Lab

Lab_schedule 6

12/5 (#17) (#17) (#17) 12/6 Open Lab 12/9

ORAL REPORT (NMR, ESR)

POSTER PRESENTATION

(NITROGEN)

ORAL REPORT

(Laser)

12/10 ORAL REPORT

(NMR, ESR)

POSTER PRESENTATION

(NITROGEN)

ORAL REPORT

(Laser)

12/11 LAB CHECK-OUT

Sign-up sheets for presentation of oral reports will be posted on the bulletin board .

“It looked insanely complicated, and this was one of the reasons why the snug plastic cover it fitted into had the words DON’T PANIC printed on it in large friendly letters” -- D. Adams, “The Hitchhikers Guide to the Galaxy”

Ethics-1

1.5 Standards for Academic Honesty Doubtlessly for a society to function as such, it should be based on trust.

Decision making, from seemingly small everyday actions to important political matters, conveys a large component of ethical conduct. Unfortunately, the world is full of examples in which this trust is violated, making it sometimes hard to tell right from wrong. Nevertheless, this trust is sustained by the ethical conduct of each individual.

Every decision has an ethical component. Luckily, in a laboratory course like this one it's really not difficult to tell right from wrong. The MIT policy on academic misconduct is very strict. "MIT assumes that all students come to the Institute for a serious purpose and expects them to be responsible individuals who demand of themselves high standards of honesty and personal conduct. Cheating, plagiarism, unauthorized collaboration, deliberate interference with the integrity of the work of others, fabrication or falsification of data, and other forms of academic dishonesty are considered serious offenses for which disciplinary penalties can be imposed."1

Where does ethical conduct come into the picture? Experimental scientific work requires, among other things, background knowledge (why do we want to do the experiment, what do we want to get out of it), experimental skills (how do we do it), scientific ethics (what are we going to do with the information we obtain from it, what if the experiment fails, etc.), and a large dose of motivation. Motivation to study, motivation to learn, motivation to discover, or even motivation to obtain a good grade. Lack of motivation is one of the principal causes of failure in experimental work, especially in a laboratory course. This lack of motivation is usually accompanied by a weak background preparation, an overlook of experimental techniques and procedures, and in several cases, unethical behavior. Motivation is very personal and cannot be provided or taught. On the other hand, the background knowledge you need to perform an experiment is mostly built during your lecture courses. It is in laboratory courses like this one where you learn the experimental skills as well as the basis of ethical scientific behavior.

Unethical scientific behavior can take several forms. "Making up data or results (fabrication), changing or misreporting data or results (falsification), and using the ideas or words of another person without giving appropriate credit (plagiarism), all strike at the heart of the values on which science and society are based."2 These different forms of unethical scientific conduct have a broad range of consequences depending on the seriousness of the offense. For example, copying a lab report from a classmate or cheating on an exam usually results in failing the class. Publishing forged data in a scientific journal can result in the loss of reputation or even ruin the career of a scientist. Hiding vital information can produce a large economical damage or even lead to loss of life. (See "http://onlineethics.org./text/index.html" for more information and some important and very interesting case studies.)

1 "MIT Policies and Procedures", (http://web.mit.edu/policies). 2 "On Being a Scientist. Responsible Conduct in Research", 2nd. Edition, Committee on Science, Engineering, and Public Policy, NAS, NAE, IOM, National Academy Press, Washington, D.C., 1995. (http://bob.nap.edu/readingroom/books/obas/) From the section “Misconduct in Science”.

Ethics-2

Frustration is not a foreign feeling to a student or a scientist. It is not unusual that experiments fail the first time, the second or, sometimes, even third time they are performed. Occasionally the data collected during an experiment is not as easy to interpret as one would expect, or would like; or the compound from a synthesis doesn't look like it is supposed to look or doesn't have the properties it is supposed to have. What are the acceptable and unacceptable alternatives in cases like these? It certainly seems easier and less time consuming to copy a lab report from previous years instead of spending a whole weekend on it. It could be tempting to forge or make up data or even copy it from a classmate, instead of investing time repeating an experiment that failed or even admitting that the experiment failed. Someone could argue "It's just a lab report." Even apparently "minor" gestures like the one described above undermine the foundations of the academic system and should be taken very seriously.

Good scientific behavior is built throughout the formation of a scientist, a doctor, an engineer, or a business person. The same applies to the field of health-care, business, engineering, and every aspect of life.

Unlike in the lecture courses, your actions in a laboratory course can affect, and they usually do affect, the performance of your classmates. Imagine that by accident you contaminate a solution of a reagent that your classmates will use after you. Would you inform your TA at the risk of loosing your "technique" points? Or would you keep silent and let your classmates perform the experiment with a contaminated reagent?

In some cases unethical behavior seems to be the easy way out, and some students think they can get away with it. That is certainly not the case, and we will do our best in defending the effort of those students who work honestly toward academic excellence.

Examples of conduct in 5.33 which fall in the category of academic dishonesty and will result in severe penalties:

• Copying into your lab report any section of another student's lab report or data analysis (from the current or a previous year).

• Making up and/or altering data. • Plagiarism (using material from other sources without giving appropriate credit).

Reports-1

1.6 Oral Reports, Written Reports, and Posters An important aspect of any laboratory work is presenting your results to others. In 5.33, you will be given the opportunity of doing so in three commonly used formats: oral presentation, a written report, and poster presentation. A. Oral Reports Oral reports will be presented on two experiments: Magnetic Resonance Spectroscopy (NMR and ESR) and Laser. Reports must be presented by the dates indicated on the Laboratory Schedule. Sign-up sheets will be posted indicating when orals can be scheduled. When you give your oral, your TA will record notes and “roughly” grade you immediately after you leave. Your final grade for an oral report should be available soon after all the orals in your section have been given. The LASER report will be graded on the basis of 20 points maximum, and the NMR & ESR together are graded on the basis of 30 points. In the oral report, you should come prepared to “take the initiative” and guide the oral exam. Otherwise your TA will be forced to take the initiative by asking you question after question, likely venturing into territory you may not prefer to explore. Be prepared to give an informal but well organized presentation. Your presentation should include the following elements, in sequence:

1) Introduction (what the experiment was all about); 2) Background (why you did it; go through and relevant theoretical background); 3) Experimental (what you did; describe briefly what happened in your

experiment); 4) Results (what happened; present your results and analysis); 5) Discussion (discuss your results in connection with theoretical or literature

expectations).

It’s that simple. The oral should not be a harrowing experience. Much of the preparation for your oral report will be the same as for a Notebook Report such as those you have turned in for earlier subjects. In particular, the data analysis, graphing and plotting, error analysis, etc. should be carried through to completion and the results should be presented in an appropriate from (tables, plots, etc.) for efficient communication. Theoretical background should be studied as well. Then you will bring your lab notebook, raw data, analysis, results, plots, and any other materials that are appropriate, and you will discuss your experiment with your TA. You may bring notes, books, and pretty much anything (inanimate) which will help you in your discussion. You may work with other students, use written reports from earlier years, and in general use any sources you want to prepare for your oral. You are, of course, expected to do your own data analysis and calculations. You may use any sources of help in understanding the analysis as well as any other aspect of the experiment.

Reports-2

You should plan on discussing your experiment for about 15 minutes. Your TA may interrupt with questions at any time, and may occasionally ask you to skip parts of your planned presentation. We should prepare and bring in a one-page “Long Abstract” of your presentation which summarizes the important results obtained in the experiment. The objectives of the oral are to encourage you to learn as much as possible, and to find out how much you know in an efficient manner. In an informal exam of this type there is no substitute for knowing the material. After analyzing your data and mastering the material, you will want to spend some time organizing your presentation. You will almost surely want to use some notes, especially to guide you through theoretical discussions. You may use a blackboard if you wish. You may also just show your (neatly written) notes to your TA on occasion, rather than transcribe them onto the board. (This is especially convenient if there are many equations.) Do whatever makes you most comfortable, without wasting time. You will surely need to show your TA spectra, plots, etc. As always, attention should be paid to the presentation of data and results so that they are easily understood. Write neatly, label the axes of plots, indicate units, errors, etc. Ordinarily, you will not turn in your data, analysis, results, etc. However, you must do so if your TA so requests after your oral report. B. Poster Presentation The presentation of the report for the NITROGEN SCISSION experiment will be a group presentation in a poster format. In a poster presentation, your results are presented neatly on a set of printed pages, including text and graphics, which are assembled on a poster board in the laboratory. The poster reports will be given individually; however, the three students working together can prepare the poster material together. The poster presentation is primarily an oral presentation, and in that respect you can follow the guidelines for an oral presentation. The poster is a visual aid to assist your description of the technical details of the theory and experiment and to present the results of data analysis. Your group will need to discuss all aspects of the experiment (background, methodology, data analysis, and conclusions), and refer to the poster for graphical material (i.e. graphs, illustrations, and equations) to make your point. It is important to carefully choose which material to present. A poster is supposed to reflect the essence of the experiment in a clear and succinct manner as well as to engage the viewer. You wish to have all information relevant to the discussion of the experiment available; yet you do not want to present anything extraneous. Keep written information brief.

Reports-3

Even though your poster may not contain all the plots or data analysis that you performed, be sure to bring ALL your data to the poster session. Also prepare and turn in a 4-page “Long Abstract” which summarizes the results of the experiment. You may use the poster materials as illustrations for this document. C. Written Reports You will prepare a written report on Experiment #1, Molecular Spectroscopy of Acetylene. As with the orals, any sources of help are allowed in preparing the written report. You are, however, expected to do your own data analysis and calculations. You are also expected to write everything in your own words, and understand clearly everything you write. The written report is due as indicated on the Laboratory Schedule and should be turned into the 5.33 Lab by 1:10 P.M.

The purpose of this report is to summarize clearly and concisely the results you have obtained in the laboratory and to convey that information to people who have not carried out the measurements but need to know the results -- in this case, your teaching assistant and laboratory instructor. Thus, the appropriate format is that of a technical report to a supervisor rather than a "journal article", which is supposed to report only new results that have never been obtained by anyone else before. The structure of the report should be as follows (a similar structure applies to the poster, but without extensive text): Title Page • Include title of experiment, your name, name of lab partner(s), name of teaching

assistant(s).

Abstract • Include on title page • Summarize principal results and conclusions in about 50 words.

Introduction • Purpose of the experiment • References to sources and literature you used (including laboratory manual) • Methods employed to obtain and analyze data • State the significance of the results to be obtained, but do not give results here (that

comes later!) Experimental Section • Summary of experimental procedures -- do not repeat directions, diagrams, etc. in

manual (reference as needed) but indicate any significant changes you made in the procedure

• Document all measurements and observations in figures and tables.

Reports-4

Results • Provide original (or photocopies of) data sets • Present results in most convenient form (charts, tables, and/or graphs) • Include a sample calculation for each type of analysis. • Include error analysis with each principal calculated result. Present uncertainties as

+ values in tables (95% confidence limits as appropriate). Discussion • What conclusions can you draw from your results? • Do theory and experiment, or measured vs. literature values, agree or disagree within

the standard error of the measurement (see above)? • Identify sources of error, areas in which procedure can be improved, suggestions for

future development of this experiment. General comments on style and format A guide to writing laboratory reports can be found in Chapter 8 of R. J. Sime, Physical Chemistry: Methods, Techniques, Experiments, Saunders College Publishing, Philadelphia, 1990, (available in room 4-449) • For both the written and poster presentations, you should try not to spend a lot of time

on fancy word processing, text formatting, etc. The key objective here is to present your results in a clear, concise, easily readable (or viewable) format. Hand-written equations (as needed) are perfectly acceptable, as long as they are clearly readable.

• Please check grammar, syntax, spelling, etc. carefully. Penalties will be assessed for poor English usage (yes, we do care about things like that)!

• Use standard notation and abbreviations for symbols, units, etc. • Use standard reference formats for cited literature -- e.g., "A. Einstein, Ann. der

Physik 17, 132 (1905)" for a journal article. • In scientific writing, the personal pronoun "I" is not generally used, particularly when

you are reporting on work carried out in collaboration with others [but this can sometimes lead to problems, as the following article demonstrates!].

Notebooks-1

1.7 Notebooks Review Chapters 2 and 3 of the Laboratory Technique Manual. Purchase from the Stockroom a STUDENT LAB NOTEBOOK (with 100 Carbonless Duplicate Sets) and use it to keep a record of everything you do which is related to your lab work. You must turn in the COPY sheets at the end of each period. Other material such as spectra, samples, graphs, and computer printouts should be “incorporated” into the notebook by reference. Assign all such materials a number when they are first produced and referenced in the notebook. The number should consist of the notebook number, the page number of the first reference, and a letter A,B,C,... to sequence the references on this page, e.g., 3-47B identifies the second item referenced on page 47 of your third notebook. Label the item with this number, your name, the date, a brief descriptive name, and other relevant information. Enter the number in the margin opposite the first point at which this item is referenced in the text. The nature of the item referenced should be made clear in the text. Use all the space in your notebook in sequence; never leave blank space to be filled in later. Whenever you start a new activity, enter a clear heading in the notebook to begin the section recording this activity. Keep work on different projects on different pages by X-ing out the remaining space on a page and starting a new page when necessary. At the end of each experiment, you will present a report of your work (see section 1.10). You should bring your notebook and incorporated materials to your oral, and you may be asked to submit them to your TA after the oral. Your notebook should contain a complete record of all of the work you have done including: 1. Description of procedures, observation, thoughts, and activities in the laboratory.

You should not copy directions from the experiment description into your notebook, but should describe all the procedures you follow as you do them. Clearly labeled sketches of experimental setups are usually better than lengthy descriptions. You don’t need to copy sketches from the handouts into your notebook, and shouldn’t unless you find it helpful. You can simply refer to the experiment description in your notebook.

2. Data, error estimates, conditions, times, spectra and other related information.

All “incorporated” materials should be referenced in the notebook and clearly labeled.

3. Calculations and graphs. Graphs should always be done separately on good

quality graph paper if they are to be used quantitatively. Sketches and plots may be put in the notebook.

4. Analysis of results and errors. The reproducibility and precision of data should

always be examined. Establish the major sources of error in data; this can

Notebooks-2

frequently be best accomplished by experiment, rather than surmise. Include detailed a statistical error analysis only when appropriate.

5. Discussion, interpretation, and conclusions. Whenever possible, the outcome of

your work should be quantitatively and qualitatively compared to that of other workers and established values. Questions in the experimental write-up should be answered.

Notebook entries in categories 1 and 2 should always be done in the lab within a few minutes of the time the work is actually done. Entries in category 3 should almost always be done in the lab as well. This is not obvious at first, but a little experience should convince you that this is best. When calculations and graphs are done immediately, problems with the quality, internal consistency, and validity of data become evident in time to go back to the experiment and change conditions or procedures to correct the problem. This is much more efficient than having to return to the lab on another day to repeat work. If you make this a regular practice, then only categories 4 and 5 will need to be added before your oral presentation. The validity and utility of the laboratory notebook record is largely determined by its timeliness, completeness, organization, and clarity. Many of you find that these are somewhat contradictory requirements. Procedures followed and observations must be recorded, however, as they occur. It is annoying at first to have to take time to do this, but it is an essential part of labwork. It can be done; it just takes more time in the lab. In the long run, be assured that it actually saves time. If you find that despite your best efforts in the lab, organization and clarity suffer unduly when you make in-lab notebook entries, make a practice of adding summary sections at the end of each day, reviewing the work accomplished and results obtained. This is a perfectly legitimate practice (if it is clearly identified as an out-of-lab summary) and is encouraged. The practice of making all of your notebook entries in this way (not while you are actually in the lab) is unsatisfactory and will not be tolerated. TAs will check notebooks in the lab from time to time to see that you are using them as you do the work.

1.8. Books The following are required and may be purchased from the stockroom, Room 4-450. 1. A laboratory research notebook (or two). 2. PC-formatted diskettes for Experiment #1 & #3. 3. A 3-ring binder to hold this Manual and additional handouts during the semester. Additional references are given in each Experimental section.

The references below are available but are not required.

1. Laboratory Techniques Manual, Volumes I & II (Both volumes available in the stockroom for use in the laboratory.)

2. Shoemaker, D. P.; Garland, C.W.; Nibler, J. W. Experiments in Physical

Chemistry, Sixth Edition, McGraw-Hill, New York, 1996 (available in the room 4-449).

3. Leonard, J.; Lygo, B.; Procter, G. Advanced Practical Organic Chemistry, 2nd

Ed.; Blackie Academic & Professional , London, 1995 (available in the room 4-449).

Grading 1

1.9 Grading and Expectations A. Grading Your grade in 5.33 will depend on the sum of scores for each of the four experiments. The grade for each experiment is largely determined by the report, but will also reflect “technique grades”. There is no predetermined percentage of letter grades to be awarded. The breakdown is as follows: Experiment # 1 IR Spectroscopy Written Report 20 points Experiment # 2 NMR & ESR Oral report 30 points (20 NMR + 10 ESR)

Experiment # 3 Time-Resolved Oral report 20 points Spectroscopy

Experiment # 4 Nitrogen Scission Poster (15) plus Long Abstract (5) 20 points

TOTAL 90 basis points TAs will grade the individual experiments according to the following principles. The number of points given will primarily reflect the understanding of the experiment (in theory and practice), the analysis and interpretation of the data, and safe laboratory practice. The data quality, presentation, and the experimental skill of the student will also be considered, although to a lesser extent. The manner in which these guidelines are implemented will vary somewhat with the type of report (oral, written, poster). The grade is partially subjective since the TAs must weigh the quality of the laboratory technique (including note taking) and the use of proper safety precautions in lab. B. Preparation Although they are demanding of laboratory skills and do introduce a number of new experimental techniques, the experiments in 5.33 are more oriented toward fostering a synthesis of your understanding of the concepts and theory being a phenomenon than was the case in 5.32 or 5.311. In other words, you cannot come into the lab without having read the experiment. Moreover, oral presentations will be expected to show a real grasp of the concepts underlying the lab work. The TAs assigned to each experiment will have worked on the experiment before the start of the term. They will have been chosen because their area of graduate work

Grading 2

corresponds roughly to the area of chemistry related to the experiment. You are encouraged to ask lots of questions while you are working on the experiment. This will be most effective if you have done your homework and know useful questions to ask. In any case try to get to know one or both of the TAs assigned to an experiment when you do it; see that they get to know you as well. Questions, suggestions, comments, and complaints which are not handled by the TAs should be redirected to Prof. Tokmakoff or Dr. Gheorghiu. You should usually find that it is best to go first to the TA assigned to an experiment concerning any matter related to that experiment. C. Late Work Completion of orals or written work may be delayed in extraordinary circumstances. Extensions must be obtained in advance by permission of Dr. Gheorghiu and arrangement with the TAs assigned to the experiment. A non-expungible penalty of 0.25*n points/day, n number of late days (vacation days, holidays and weekends are not included) will be deducted for work completed after the due dates. Please note that this penalty does not apply to the last day of labs, Wednesday December 11. No work may be submitted after that date (Institute regulation). D. Waste Inventory and Disposal.

In keeping with the growing trend toward accountability and eventual reduction of hazardous chemical waste, we are now requiring that students keep track of their waste and turn these records in with their lab reports. This also assists us in meeting E.P.A. regulations concerning record keeping. Waste inventory and disposal sheets for each experiment will be found in Section 2.0. Failure to turn in properly filled out sheets will result in a penalty of 2 points on the report.

Varia-1

1.10 Sundry Other Matters You will notice that there are no “Grade Sheets” in this manual. You should have sufficient lab experience by now to know that technique and performance in the lab, keeping an accurate and organized record of experimental procedures and results in your lab notebook, proper analysis, presentation, and discussion of your results, and thorough understanding of the experiments are all important and will therefore be considered in determining your grade. Medical Problems and Incompletes Students unable to complete part of the work in the course due to medical problems should contact Dr. Gheorghiu and the TAs associated with the relevant experiments at the earliest possible date to negotiate a schedule for completing the work. In extraordinary cases where the work cannot be completed by the end of the term, a grade of “incomplete” may be granted but only if less than 20% of the course work remains to be submitted and all lab work is substantially complete. Legitimate medical problems will be the only grounds considered for granting incompletes. Suggestions You are encouraged to make constructive suggestions, comments, and criticisms of any and all aspects of our operation of the subject. These may prove helpful for the subject this year and/or for students taking the subject in later years, and will not result in a lower grade!

‘... the task we have designed you to perform is this. We want you to tell us ... the Answer!’ ‘The Answer?’ said Deep Thought. ‘The Answer to what?’ ‘Life!’ ‘The Universe!’ ‘Everything!’ Deep Thought paused for a moment’s reflection. ‘Tricky,’ he said finally. ‘But can you do it?’ Again, a significant pause. “yes,’ said Deep Thought. ‘I can do it.’ ‘There is an answer? A simple answer?’ ‘Yes,’ said Deep Thought. ‘Life, the Universe, Everything. There is an answer. But,’ he added, ‘I’ll have to think about it.’ –– D. Adams, Hitchhikers Guide to the Galaxy, Chapter 25