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

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

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

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 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

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

X-Ray diffraction is an important and powerful tool for determining the solid state structure of compounds. Modern advances have made data collection and structure solution almost routine for many small molecules To use this technique, however, good quality single crystals are still needed. In this exercise you will experiment with the art of growing single crystals

For a two-solvent recrystallization, you should have one solvent (solvent #1) in which your desired compound is soluble at the boiling point. The second solvent(solvent #)should induce crystallization when added to a saturated solution of your compound in the primary solvent. Reference:

Working on a vacuum manifold: See LLP chapter 9.2 for an excellent discussion on working with air-sensitive reagents, including how to use a two-way manifold. De-gassing solvents: The best way to remove water and oxygen from a solvent is to distill it over an appropriate drying agent (such as sodium). This can sometimes be a lengthy (and dangerous)task. Since we