CHEM 474 Laboratory Exercises
Last Update: August 30, 2012
Some of the possible exercises available for you to complete this semester are given below. Many of them are taken from different sources, some of which may give much more information than you actually need and some of which are on a scale that is much larger than is needed for our purposes. While you will be provided with copies of the complete article or laboratory exercise, you will need to first strip away the unnecessary to give what we are interested in – the synthesis and characterization of a particular compound. You must be pay particular attention to the amount of reagents being used and the amount of material being prepared. Some of the procedures given may be on a scale that is much larger than is necessary for our purposes. In all cases, you should be planning to obtain about 500 mg of the final product, which will be enough for a complete characterization of the compound. Students who use excessive amounts of reagents, or who generate excessive amounts of waste, will be penalized.
In all exercises the minimum characterization that is required includes: the IR spectrum, the UV-Vis spectrum with molar absorptivities (if colored and soluble), and the 1H (with peak positions, in ppm, multiplicity and coupling constants) and 13C (with peak positions in ppm) NMR spectra for diamagnetic compounds. A melting point determination is not included in this list because many coordination compounds are salts with high melting points. And while a melting point may not be very useful in the characterization of your final product, you may find it useful to determine the melting point of organic ligands as part of their characterization. In any case, melting points should be determined only for compounds whose melting points are reported to be less than 200 °C. It is a good habit to routinely run a TLC of the product of a reaction before attempting spectroscopic characterization. Is many research universities and in some industrial settings, NMR time is precious and people who do not waste it by running impure materials will be rewarded.
Characterization beyond the minimum required (e. g., X-ray structure determination, cyclic voltammetry, magnetic moment, etc.) will be rewarded. You must clear any additional work with your instructor before attempting any work of this sort!
In some of the exercises the identity of the product is not given. You will need to identify the product (or products) using standard methods and the additional information that you will be provided. In these cases you are also free to use any other method of analysis that we have at Truman, but you must clear it with your instructor first.
- Synthesis of a Porphyrin and its Metal Complex
- Template Synthesis of a Macrocyclic Ligand
- Synthesis and Resolution of Cobalt Ethylenediamine Complexes