equipment and supavision by appropriate individuak You bear the sol responsibility, liability, and risk for the implemcntation of such safety procedures a ares. MIT shall have no responsibility, liability, risk for the content or implementation of of the mat

Chemists use spectroscopy (Ir, UV-Vis, NMR) to determine molecular structure. spectroscopy: technique that measures the amount of radiation a substance absorbs at various wavelengths(based on the quantization of molecular energy levels Molecules exist in quantized energy states (rotational, vibrational, and electronic quantum states) Molecules absorb discrete amounts of energy(ae)and are excited to higher

described in these materials are potentially hazardous and require a high lcvel ofsafity training special facilitics and equipment, and supavision by approprinte duals. You bear the sol responsiblity, liability, and risk for the impkemcntation of such safety procedures and measures. MiT shall have no responsibility, liability, ar risk for the content ar implem of ay of the matcrial presented. Legal Notices

This is two-day- experiment. Do not start this experiment unless you have two free lab days to complete it.*** Techniques Checklist: Picking the correct eluent Adsorbtion of a crude mixture onto silica gel Separating complex mixtures using gradient elution Pre-lab Discussion: Suggest limited list of eluent solvent systems Discuss sample adsorption and gradient elution strategies

described in these matorials arc potentinlly hazandous and require a high levd ofsafety training spccial facilitics and equip mant, and supervision by approp iate individuals. You bea the sole responsibility, lisbility, and risk for the implamnentation of such safcty procedures and mcasures. MIT shall have no respongibility, liability, or risk for the content or implementationc any of the material presanted. Legal Notices

dscnibed in these materials are potentially hazardous and require a high level ofsafcty training special facilitics and equ by approp lividuak You bear the sole responsibility, liability, and risk for the in plementation of such safety procedures and measures. MIT shall have no responsibility, liability, or risk for the content or implementation of amy of the matcrial presented. Legal Notices

Thin Layer Chromatography (TlC) is an extremely useful technique for monitorin reactions. It is also used to determine the proper solvent system for performing separations using column chromatography. tLC uses a stationary phase, usually alumina or silica, that is highly polar(standard) or non-polar(reverse phase). The mobile phase is a solvent whose polarity you will choose. In 5.301, and in most lab

Overview: As you may discover, growing single crystals takes patience as well as an artful hand Crystallizations can be very sensitive to temperature and minor disturbances. Therefore, you will be encouraged to try several different temperatures using otherwise identical conditions, and to always find a quiet undisturbed location to promote crystal growth. Here are some tried and true tips to get

Overview: A good 'H NMR sample contains about 10 mg of compound. The solution should contain no solids or paramagnetic impurities. Your deuterated NMR solvent should be free of water,and your NMR spectrum should contain no solvent peaks. Reference: Zubrick page 295 is relatively useful, but you should follow the specifics in this handout Also, keep in mind that we won't be running continuous wave spectrometers, so you should disregard any discussion of them. NMR Solvents:

This handout describes standard extraction and washing protocols that can be applied to virtually any crude reaction mixture. Aqueous washings are done to remove water soluble impurities from organic products since normally the compound that you desire will be dissolved in Reference