Course Information



Course Description




Experiments

This laboratory course will acquaint you with common techniques for the synthesis and characterization of inorganic and organometallic compounds. You will carry out 6 regular projects that will include syntheses of nonmetallic compounds, coordination complexes, organometallic compounds, bioinorganic molecules, and solid state materials. During the last three weeks of the semester, you will conduct a special research project in order to provide some insight into original inorganic chemical research. You must work independently and you may not use other people's data.


Reports

Effective communicating skills are essential to a successful career in chemistry. This course places strong emphasis on the quality of written reports. Your report must follow exactly the format prescribed and must be submitted on time, one week after completion of the experiment in lab.


Conference Hours

In the conference hour, I will discuss techniques of effective scientific writing, inorganic synthesis techniques, and methods of characterization for inorganic complexes.


Reference Texts

On Reserve in Chemistry Library:

Adams, D. M.; Raynor, J. B. Advanced Practical Inorganic Chemistry; Wiley: New York, 1965.

Angelici, R. J.; Girolami, G. S.; Rauchfuss, T. B. Synthesis and Technique in Inorganic Chemistry; 3rd Ed., (preprint).

Dodd, J. S., Ed.; The ACS Style Guide; American Chemical Society, Washington, 1986

Dolphin, D. The Porphyrins; Vol. 1; Academic: New York, 1978.

Gordon, A. J. The Chemist's Companion; Wiley: New York, 1987.

Jolly, W. L. The Synthesis and Characterization of Inorganic Compounds; Prentice-Hall: Engelwood Cliffs, NJ, 1970.

King, R. B. Organometallic Syntheses; Vol. 1; Academic: New York, 1965.

Nakamoto, K. Infrared Spectra of Inorganic and Coordination Compounds; 4th Ed.; Wiley: New York, 1986.

Shriver, D. F.; Drezdzon, M. A. The Manipulation of Air-Sensitive Compounds; Wiley: New York, 1986.


Other References

Inorganic Syntheses; Vol. 1-17; McGraw-Hill: New York // Vol. 18-31; Wiley: New York.

Brauer, G. Handbook of Preparative Inorganic Chemistry; 2nd Ed.; Academic Press: New York, 1963.

Cotton, F. A.; Wilkinson, G. Advanced Inorganic Chemistry; 5th Ed.; Wiley: New York, 1988.

Eisch, J. J. Organometallic Syntheses; Vols. 2 and 3; Academic Press: New York, 1981.

Perrin, D. D.; Amarego, W. L. F. Purification of Laboratory Chemicals; 3rd Ed.; Pergamon: New York, 1988.

Abel, E. W.; Stone, F. G. A.; Wilkinson, G. Comprehensive Organometallic Chemistry II; Vol. 1-14; Pergamon: New York, 1994.



Grading Scheme

Grades will be assigned based on the point total accumulated during the semester. You must complete all laboratory reports to pass this course.
  1. Safety Exam: 20 points
  2. Quizzes @ 10 points each: 40 points
  3. Standard experiments @ 100 points each: 600 points

      Scientific Writing (50 points):
    1. Direct usage/ strong verbs,
    2. Correct grammar/spelling/hypenation,
    3. Correct format,
    4. Clarity and conciseness,
    5. Correct use of abbreviations/lack of slang

        I will suggest correction to improve the composition of your report. After you have made all appropriate corrections and I have approved the scientific writing in the report, you will submit it to a TA for the grading of experimental content.


      Experimental Content (50 points):
    6. Yield and purity of product,
    7. Quality of data,
    8. Analysis of data,
    9. Sufficient detail in the write-up,
    10. Significant figures/computations,

  4. Special project: 150 points
    (report: 100, progress and creativity: 50)

  5. Lab Notebook: 50 points

  6. Laboratory Performance (10 points/laboratory period): 140 points

    Total = 1000 points




Late reports: Reports are due one week after completion of the experiment in the lab. Late reports will be penalized by 10% per day late.

Graduate students who take Chem. 404 for 1/2 unit will be required to perform only 2/3 of the standard experiments plus the special project (11 weeks total), while students who register for 1/4 unit will only be responsible for 5 weeks of the standard preparations but not the special project.

About the special project: The selection of the special project is an important part of this course. The formulation and planning of the special project is the first step, and you are encouraged to pick a topic that you find interesting. Graduate students normally choose projects based on their proposed thesis research. Undergraduate students are encouraged to design their own special project, or pick one from a list of selected experiments.

Special projects consist of a series of synthetic investigations which culminate in the preparation of a compound with a special property or structure or whose synthesis illustrates special methodology.

The following guidelines apply in the selection of a special project:

1) It must emphasize inorganic chemistry. Extended syntheses of ligands
are inappropriate.
2) At least the first half of the proposed experiment must be well documented
in the literature. This helps us (and you) evaluate your success.

Laboratory Directions

Equipment Drawers: Glassware and various pieces of apparatus are in labeled drawers in the laboratory. At the end of every lab period, it is your responsibility to leave the apparatus clean and in good working order also.

Tools and Wire: A place in the laboratory has been provided for tools. Please replace tools (and wire) immediately after use so the entire lab does not have to be searched when a tool is wanted.

Vials and Bottles: Use vials rather than flasks to hold chemical samples for microanalysis and for long-term storage.

Magnetic Stirring Bars: The teaching assistants have a supply of magnetic stir bars. Be sure to return the cleaned stir bars to the TA at the end of the lab period.

Broken Glassware: Report broken glassware to a T.A. immediately.

Glassware-in-common: There is a limited supply of glassware for use by everyone in the lab, so it is imperative that the turnover rate be as high as possible and that no "hoarding" occur. Clean glassware immediately after use. A Kimwipe wet with hexane will remove grease. Soap, water, and a brush will clean most glassware. Clean frits by rinsing with an appropriate solvent, and, if this does not suffice, by treating with conc. nitric acid or aqua regia (in the hood), rinsing with water, and drying briefly in the oven. Don't store products in flasks. Transfer products to bottles or vials, or in the case of air-sensitive materials, into ampules.

Base baths: If you put something into the base bath, you must sign the log book, and it is your responsibility to bring the glassware out again by the end of the lab period. Often, it is sufficient to soak a piece of glassware for only a few minutes. Glassware coming out of the bath should be rinsed with water, rinsed with 2 M HCl, rinsed again with water, and dried in the oven. Don't put fritted glassware in the KOH bath, because the KOH will dissolve it.

Hoods: Use the hoods whenever your reaction could produce noxious vapors. You should not have open containers of solvent on the benchtop. Benzene, CS2, and other dangerous solvents should be transferred in the hood. Reactions of iron pentacarbonyl, bromine, liquid phosphines and phosphites, or thiols must be done in a hood, and glassware used in such preparations should be soaked for about 30 min in a solution of Clorox.

Elemental Analysis: Pure samples of liquid and solid products can be analyzed for a variety of elements, including metals, at the microanalytic lab. Only good samples should be submitted, i.e., no crude reaction products. Enough to cover the bottom of a one dram vial is usually sufficient unless several analyses are to be done (note that CHN are usually done on the same portion of sample). The TA must approve your samples for analysis (signature on analysis slip). Indicate on the analysis slip the empirical formula of the compound, the percentages of each element to be analyzed for (to two decimal places in the percentage) and the analyses desired. Samples for analysis should be clean and dry, i.e., free of solvents; dry in vacuum, if possible. Indicate clearly on the analysis slip if the sample is hygroscopic or air sensitive, so that the analyst can take appropriate precautions.

NMR Tubes and NMR Spectra: The TA has a supply of NMR tubes. For a 1H NMR, add approximately 0.015 g of sample and 0.75 mL of a deuterated solvent to the NMR tube, cap it, label it, and hand it to the TA with a written explanation of the sample type and information needed.

IR Plates and Cells: Mulls for IR spectra are made by grinding some of your compound with a half-drop of Nujol (mineral oil) using a mortar and pestle. The paste that results may be transferred to the IR plates using the pestle. The IR plates are hygroscopic. Keep them in the desiccator until ready for use, and clean them immediately after use with absolute ethanol and a Kimwipe. The IR cells for solution work are very expensive and should be treated carefully. They should be filled only with a glass-and-stainless steel syringe (do not use plastic and rubber syringes). Rinse these immediately after use with several (i.e., three or more) syringe volumes of clean, dry solvent, and dried by gently passing a stream of N2 (not air!) through them. The gas cell for the vacuum line should be stored in a desiccator when not in use. Always pump away the gas after the IR is obtained.

Ultraviolet Light Sources: CAUTION - protect your eyes! The water jacket for the mercury vapor source is made of quartz, as is the reaction vessel. These are expensive to repair or replace, so handle very gently. Do not handle these pieces where the light passes. Fingerprints "burn" into quartz and cause fogging. Maintain an adequate flow of water through the water jacket, as the lamp is very expensive, too. If you use the Tungsten-Halogen lamp, it should be cooled with a stream of air (passed through a tube of glasswool to remove oil).

Heating and Oil Baths: Heat reaction mixtures with hotplates or heating mantles. Open flames can't be used in the laboratory. Oil baths are better sources of heat than heating mantles, as they provide uniform heat without hot spots. Mineral oil baths and paraffin baths are good to about 150 íC, at which they begin to smoke and can catch on fire. Use a silicone oil bath between 150 and 250 íC. Do not mix silicone oil with mineral oil. Silicone oil should be put in a labeled bottle after use to avoid confusion.

Vacuum Pumps and Traps: Vacuum pumps must always be trapped with liquid nitrogen. If left on overnight, be sure the dewar is filled and covered with aluminum foil. Always, when turning off the vacuum pump, vent air into it to avoid sucking oil back. Remove the liquid nitrogen trap whenever the trap is open to air to avoid condensing liquid oxygen. Always allow the trap to vent off pressure easily when the trap is taken out of liquid nitrogen, to avoid blowing the trap apart.

Mercury Spills: Report all mercury spills. All mercury spilled must be collected as thoroughly as possible. The contaminated area should be sprinkled with sulfur after collecting as much of the mercury as possible. Waste mercury should be put in the bottles labeled for it in the waste hood.

Waste Solvents: Two containers for waste solvents are provided, and reside in the waste hood. All organic solvents should be put in these containers when you discard them; do not pour them down the sink! If your solvent contains any chlorinated hydrocarbons, pour it in the chlorinated solvent container, otherwise, pour it in the non-chlorinated container. If you notice that one of the containers is full or almost full, inform your T.A.



Laboratory Notebooks

A record of your experimental observations must be kept. The notebook must be of the bound type, (spiral notebooks are not allowed) with the pages numbered consecutively.

Leave the first few pages blank for an index. In your notebook, include all observations and any changes in the suggested procedure. Each page should be titled and dated. On the first page of an experiment, write out the key reactions together with molecular weights of important reagents and the quantities used. A drawing of the experimental apparatus should be included. Particularly important data to be recorded are weighings, volumes, color changes, durations, temperatures, difficulties encountered, measurements, and yields. TLC plates should be mounted in the book. Spectra and microanalytical report forms should be cross-referenced to the notebook page number.

The laboratory notebook is a practical device for recording procedures as they were done (not as they were planned to be done) and the <observations arising from the experiments. They should be terse. All data and calculations are to be recorded directly in the notebook in ink. Recording data on odd pieces of paper, to be later edited and transcribed, absolutely will not be tolerated. An erroneous result should be neatly crossed out and an explanation of the error inserted. Experimental difficulties should be noted along with possible ways to avoid them should the experiment be repeated. Conclusions derived from the experimental results should be noted, since these will be useful when writing the formal report. While a laboratory notebook is hardly supposed to be pretty, it is fair to say that is presentation is reflective of the scientific and organizational ability of its author.

Your notebook will be collected at the end of the semester, and graded as part of your laboratory technique evaluation.


Laboratory Reports

Proficiency and ease in report writing are essential skills of every chemist. Many employers state that the greatest weakness of young chemists is their inability to report clearly the important results and conclusions of their work. This weakness frequently results from a combination of poor grammar, weak logic, and lack of precision, but most often from carelessness.

The importance of learning never to allow a carelessly written letter, technical paper, or report to leave your possession cannot be overemphasized. The greater part of your contacts with others in your career will come through the written medium rather than through personal contacts. Frequently your colleagues and superiors will know nothing more of your character and ability than what they can deduce from your correspondence and reports. Your ability is of little value if you cannot transmit what you have learned to others; good work poorly presented loses its force. The most successful chemists are not only intellectually and technically proficient, but also are able to write competently, thoroughly, and effectively.

The laboratory reports in this course are to be written in a format suitable for submission to a professional chemical journal. The following description of the format is an abbreviated version of "Instructions to Authors" that appears in the first issue each year of the Journal of the American Chemical Society. While no pretense is made that the format described below is the only acceptable form, we ask you to follow it. This may seem arbitrary, but remember that in the "real world" your reports often must conform with the ideas of others and not your own. Failure to follow the directions presented here will result in down-grading of the report regardless of its technical excellence.

The purpose of your lab reports is to convey information to your readers, and convince them to accept your observations and conclusions. Be concise and factual. Have your observations and conclusions in mind before you begin writing, and aim the whole report at presenting your results in a convincing manner. Reports should be written with a particular emphasis on clarity.


Format

Organization. The reports will consist of the following sections in order:

    1. Title page (1 page)
    2. Abstract (1-2 paragraphs)
    3. Introduction (1-2 paragraphs)
    4. Results
    5. Discussion
    6. Experimental Section
    7. References (5 minimum)
    8. Tables
    9. Figures
    10. Supplementary Material (original spectra and microanalysis forms)
    11. Samples (submit in screw-cap vials, or sealed ampules if air-sensitive)

General Instructions. The reports must be submitted via e-mail using one of the common word processing programs (such as MicrosoftWord). Corrections on writing style, grammar, etc. will be made and the report may be resubmitted. Turn in one copy of the supplementary material to the TA in your laboratory section. The nomenclature used should be consistent, clear, unambiguous, and follow currently accepted IUPAC guidelines; see "Nomenclature of Inorganic Chemistry, Definitive Rules, 1970" Butterworths: London, 1971. Registered trademarks should be capitalized (e.g., Teflon, Pyrex), while other chemical names should be uncapitalized. Metric units (SI) should be used whenever possible.

Abstract. This section should summarize your principal results. Be specific! Briefly describe exactly what compounds you made, how you made them, and what the spectroscopic characterization told you about the chemical nature of the compounds. Recommendations for changes in the procedure based on your observations may be included.

Introduction. Introductions should contain only enough background material to show why the work is important. Briefly describe the general method used to synthesize the compound concerned, as well as methods previously employed. Relevant literature references should be cited. Usually it is a good idea for the first few references in your report to be books or review articles on the general area of chemistry under discussion; these citations should be followed by references to specialized literature articles more directly related to your work.

Results. Present facts concerning the compounds synthesized. This is conveniently organized around balanced equations for each step of the synthesis. Describe the procedure used to prepare and isolate each compound. Do not go into details about the procedure unless there is something unusual or noteworthy about it. For example, crystallization solvents are not usually discussed. Describe amounts of reagents used in terms of molar ratios or molar equivalents, rather than in grams or moles. Include a physical description of the material (gas, liquid, solid, color, viscosity, odor, crystallinity, air-sensitivity), a summary of physical data used to characterize the compound (m.p., b.p., elemental analysis, vapor pressure, IR, NMR, EPR, UV-Vis, mass spectrum), and a comparison of your data with analogus data in the literature. Merely listing your data and literature values is not sufficient; thoughtful interpretation must be included.

Discussion. This section may be combined with Results under the same heading, but descriptions of results and discussions should not be intermingled in the same paragraph. The discussion should present opinions concerning the work presented. These may include discussion of the yield or quality of the product, agreement or discrepancy between data you obtained and literature results, and suggestions for improvement in the written description or actual performance of the experimental procedure.

Experimental Section. Experimental results should be clearly and logically presented under separate subheadings. The first paragraph should contain statements as to the techniques employed, the sources of starting materials, and the equipment used. At the beginning of each synthetic procedure, the full name of the compound being prepared in that step should appear as the first line of the paragraph.

Analyses. Analyses should be reported in the following format in the Experimental Section after the yield: Anal. (C18H30P2Ti). Calcd: C, 60.7; H, 8.4; P, 16.6. Found: C, 60.2; H, 8.3; P, 17.2. Note that the percentage sign is not written. Analyses should be discussed in the text only if necessary; + 0.4% is "acceptable". Your microanalysis forms must be turned in with the report in the Supplementary Material. Along with your report, be sure to turn in your samples in screw-cap vials or in sealed tubes if air-sensitive.

Spectra and Spectroscopic Results. Spectroscopic results must be reported in full in the Experimental Section after the analytical results and the melting point if any. IR spectra should include the location of the band in cm-1, and its relative strength (s = strong, m = medium, w = weak); shoulders are indicated by sh. Thus: IR(Nujol): 2100(s), 2096(sh), 1870(w) cm-1. If your spectrum was taken in solution or as a Nujol mull, you should specify this but you should not report the solvent or Nujol peaks in your list. NMR spectra should include solvent, temperature, reference used (e.g., TMS), chemical shifts in d units, the multiplicity of the peak, magnitude of coupling constants (if any) in Hz, and the assignment. Thus: 1H NMR (CDCl3, 25 deg C): d 5.29 (t, JPH = 6.0 Hz, PMe). UV-Vis spectra should include the solvent, temperature, and the positions of the peak maxima in nm. Thus: UV-Vis (toluene, 25 deg C): 470 nm. Original spectra must be included in the Supplementary Material.

References. References to the literature should be numbered in one consecutive series, repetition of references being avoided by using the superscript number corresponding to the original reference. Reference numbers in the text should appear as unparenthesized superscripts, but enclosed in parentheses in the collected references following the text. Literature references should be arranged and punctuated as shown:

(1) Doe, J. S.; Smith, J.; Roe, P. J. Am. Chem. Soc. 1986, 108, 8234-8265.

(2) Smith, A. B. Textbook of Inorganic Chemistry; Academic: New York, 1986; pp 123-126.

Inclusive pagination is required. Some references can be comments; there should be no footnotes on the pages where the text of the report is presented.The journal abbreviations that should be used are given in the first issue of each year in the Journal of the Chemical Society, Dalton Transactions and also in the reference text Chemical Abstracts Service Source Index (CASSI) (see the library).

Tables. One of your tables must be a comparison of your results with literature values. Otherwise, tables should be used only in case they will present information more effectively than running text. The column heads should be made as brief as possible, using abbreviations liberally. Lines of data should not be numbered unless these numbers are needed for reference in the text. Columns should not be used to contain only one or two entries, nor should the same entry be repeated numerous times consecutively. Data should not be included in one column which are deducible easily by simple arithmetic from data in another column.

Figures and Graphs. These should be carefully prepared line drawings on plain white paper or coordinate paper. Symbols (use open or closed circles, triangles, squares; do not use unusual representations) and lettering should be neat and legible. Figures should be numbered in series with a caption describing the content beneath the figure. Figures that depict spectra must have a caption that includes the experimental conditions, i.e., solvent, temperature, and units for the x and y axes.

Formulas and Equations. Empirical and structural formulas and mathematical and chemical equations should be written with care, paying particular attention to subscripts, superscripts, electric charges, and the placing of single and multiple bond lines. Electric charges should be written as + and -. Phenyl groups should be shown as C6H5 or Ph. Other groups may be abbreviated: methyl (Me), ethyl (Et), n-propyl (n-Pr), iso-propyl (i-Pr), butyl (Bu), cyclopentadienyl (Cp), etc. Unusual abbreviations must be clearly defined upon their first occurrence in the report.

Supplementary Material. This is an appendix, separate from your report, which includes originals of all the spectra you obtained and the microanalysis forms. You can also show the details of simple calculations which are discussed in the report (for example, d-spacings from X-ray powder diffraction data).

Style. Describe what you did in past tense; non-time dependent properties can be put in present tense. Use complete sentences, check spelling, and proofread! Slang, such as lab, prep, rotovapped, pumped dry, etc., should be avoided. Distinguish between "spectrum" and its plural "spectra". Also, note that it is slang to say "the IR was recorded," rather "the IR spectrum was recorded." Use direct, rather than indirect sentences.


Guide to Chemical Abstracts and Science Citation Index




316/404 Index

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