Report

Due: Wed 5 pm, Dec 10, 2008

You are (almost) on your own for this experiment. Just follow the usual report style. It may help to review the sample reports for salicylic acid, isopentyl acetate, and the general instructions in the appendix.

An outline of your report is presented below. Remember to keep each section short. Do not include a "purpose". The "results" should describe how you obtained acetylferrocene and the data that supports this structure. Although a detailed description of the chromatographic procedure is not warranted (see below), you might want to mention whether or not ferrocene was still detected in your product mixture.

Discussion. Instead of the usual post-report question, I would like your discussion of acetylferrocene's NMR spectrum to be extended so that it clearly identifies which protons are chemically equivalent and why. Acetylferrocene contains 12 protons, but only 4 signals are observed in the NMR spectrum (note: ferrocene contains 10 protons, but produces only 1 signal). Therefore, there could be symmetry in the molecule making different protons chemically equivalent, or effective symmetry (created by rapid conformational changes), or both (please assume that none of the protons are "accidentally" equivalent). If you believe acetylferrocene is symmetric, describe whether the symmetry element is a plane or axis, its location, and the protons that are made equivalent by it. If you believe there is effective symmetry, describe the motion or geometry change that is responsible and the protons that are made equivalent by it. (Note: We have never discussed the geometry or conformational preferences of sandwich compounds so you should come to this matter with an open mind. Let your data be your guide.)

Talkin' chromatography. Chromatographic procedures are highly standardized so very little procedural detail is needed (it might be helpful to review the isopentyl acetate lab report and see how the gas chromatography procedure and data were described in different parts of that report). With dry column flash chromatography, you only need to give the name of the technique and the materials that you used (silica gel, solvents). There is no need to mention fraction size, number of fractions, follow-up TLC analysis, or rotary evaporation at least as far as the isolation of acetylferrocene is concerned. Thus, a simple phrase like the following could be completely adequate for your experimental section: "Dry column flash chromatographic purification (silica, hexane-ethyl acetate) of the crude product (2.04 g) yielded pure acetylferrocene: 1.08 g (15% from ferrocene), blah-blah". Of course, even less procedural detail should be provided in other sections of your report.

NMR spectra & TLC drawings. Attach all of your NMR spectra to the report. Do not attach your TLC plates or drawings.

E-Factor. Make sure you include the silica gel and solvents used to purify your product. (Note: I don't know if Pat will want E-factors reported for Chem 202 experiments. You'll have to ask him next semester.)

Sample Report

Synthesis of Acetylferrocene from Ferrocene

Ferris Wheel

Thurs lab, Box 1100

Abstract

Results and Discussion

Experimental

Preparation of acetylferrocene.

References

E-factor
Insert list and mass of discarded materials, product, and e-factor here. You will almost certainly notice that the chromatography procedure (include silica gel, include weight of solvent used for fractions) leads to a much larger e-factor (much more waste) than previous experiments

Figures
[attach NMR spectrum: full spectrum + useful expansion with peak picks]