How to be a Successful Organic Chemist

25 14 How to SURVIVE an organic chemistry experiment Introduction We have talked about preparation, safety and all the processes that should happen before an experiment. Now we will move on to the actual experiment itself.The aim of this chapter is to contextualize the organic chemistry experiment, and discuss the different phases of the experiment. You will find that most experi- ments follow the same general outline, which should make it easier to prepare. 4.1 Typical flow of an organic chemistry experience There are typically three phases associated with an organic chemistry experiment: Phase 1: Set-up and reaction The reaction apparatus is set up, and the reactants and solvents are measured and mixed together.The reac- tion mixture is stirred, and heating the reaction mixture is often necessary. Phase 2: Work-up and purification The reaction mixture is often quenched with water, and then work-up is performed. Work-up can be a combination of the purification techniques discussed in chapter 2, such as extraction, filtration and/or dis- tillation. The aim of this phase is to separate the main product from the other components, and isolate it in high purity. Phase 3: Characterization The obtained product is analyzed by means of different techniques, such as melting point analyses, and IR spectroscopy. The aim of this phase, is to obtain information about the identity and the purity of the product. Keeping this organization in mind can be valuable, as it firmly cements the purpose of the experiment. Each phase has distinct purposes, which all funnel into the overall goal of the experiment. The set-up and reaction phase is all about setting up the conditions of the experiment. We want a certain chemical reaction to take place, and must add reactants in exact proportions, with solvents and potential catalysts.The reaction conditions, i.e. the temperature, the time and other parameters, are usually defined at the outset. This phase is also crucial in determining the success of the experiment. Without weighing out correct quantities of reactants, for example, or heating the mixture to the correct temperature, the desired reaction may not find place, or competing side-reactions might happen instead The work-up and purification phase usually involves the most skill and technique. After the reaction stage, we have a mixture of potentially unreacted starting materials, products, solvents and byproducts. At this stage, a series of purification techniques are employed to isolate the product, from this mixture.