Organic Chemistry Reagents And Their Functions Pdf Download !FULL!
Organic Chemistry Reagents And Their Functions Pdf Download
Most organic syntheses are conducted using an organic solvent. The solvent in the reaction vessel contains a mixture of water and organic solvents. As the reactions progress, there is a steady build up of impurities and by the end of a reaction a certain degree of heterogeneity in the mixture of solvents will exist. Thus, the solvent in the reaction mixture will have a specific composition depending on the chemistry conducted. The mixture is said to be saturated when the composition is homogeneous, that is there is no tendency for the mixture to separate into two or more layers. A test for a given set of reactions is to perform at least one of the reactions under study with each pair of reactants or reaction (bromination, esterification and the like) in the mixture in turn. If the reaction is conducted as planned the reactions with the different solvents will proceed to completion at the same time.
The two most common organic solvents are ethers and alcohols. The ethers are very versatile reagents, e.g. di- or polyethers, can be synthesized from simple alcohols and a stoichiometric amount of a base in an ether. Alcohols are liquids that contain one hydroxyl group per molecule and can be synthesized from acids and a stoichiometric amount of a base in an aprotic solvent, i.e. an organic solvent that does not interact with the electrons in the molecule. The class of alkanes (paraffins) is also readily synthesized by the addition of a stoichiometric amount of a base to an acidic solution of one or more terminal alkyl acids such as hexanoic acid or 2-butenoic acid. The two basic classes of organic solvents are represented by the following scheme:
All other things be excepted, the only thing chemists should really be bothered about is how their reagents will react with the reactants. They are no more interested in what happens to the reagents than they are in the products the chemistry produces. All that really matters is whether the chemistry is successful or not. One thing that the synthetic organic chemist will eventually come to realize is that there is little if any advantage in making a transformation to something exotic if the chemistry isnt going to work. Remember, it is the stuff in the flask, not the magical transformations that makes it possible to conduct the experiment.
One of the great things about chemistry is its modularity. This is more true than ever in the development of computer software. The structure of a chemical reactant is, with some exceptions, such a simple and minimal part of it that the vast majority of organic chemistry syntheses can be handled without knowledge of either the product or the reagent. And, this rule goes for most laboratory experiments.
The ideal reagent is expected to have the following characteristics : a high degree of reactivity, the capacity to form stable and specific products, the lack of contamination in the product, a lack of toxicity, and the ability to function in aqueous solvents. The best reagents can also be expected to be stable in organic solvents or to separate well from the products of the reactions. The last criterion is important since separation of products from precipitating reagents can be very labor intensive and of little or no use if you have too many reagents to work with. It also sometimes affects the purity of the products so that it is important to minimize the number of reagents used.