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

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

6.1 确定分子量和元素组成式 6.1.1 由EI谱确定分子量 6.1.2 由ESI谱多电荷离子峰簇求分子量 6.1.3 解析软电离的谱图得到分子量 6.1.5 峰匹配法（peak matching） 6.1.6 用低分辨质谱数据推测未知物元素组成

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

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:

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:

WARNING NOTICE: The erperimants described in these matcrials are potantially hazardous and require a high level ofsafcty training special facilities and equipment, and supervision by appro responsibility, liability, and risk for the implemontation of such safey procedures and meastncs. MIT shall have no responsibility, liability, or risk for the content or implementation any of the matainl presented. Legal Notices

在本影片中学习如何熟悉滴定技术---用酚?在酸/碱滴定中的详 细示范。 Learn how to master the art of titration in this video-with a detailed demonstration of an acid/base titration using phenolphthalein