The Different Types of Solvents
There are different types of solvents in organic chemistry that can effect on nucleophilic substitution reactions. We know that polar dissolves polar and nonpolar dissolves nonpolar. There are three types of solvents in organic chemistry; non-polar solvents, polar protic solvents, and polar aprotic solvents.
We have two common non-polar solvents called heptane and cyclohexane. What we find in organic chemistry is non-polar solvents are not very good for most substitution reactions. The next type of the solvent is polar protic solvents. Polar protic solvents include methanol, ethanol, water, amine, and carboxylic acid. What we find with all these solvents is hydrogen bonding. In the molecules of these solvents, you can find a hydrogen bonded to either an oxygen or a nitrogen. There is a partially positive charge on the hydrogen so it makes it simply ionizable. That hydrogen is attracted to the negative charge of the nucleophile. So it is going to hinder or slow the reaction. Then we can say that our nucleophile is solvated and it’s turned into a weak nucleophile. Because of this, polar protic solvents favor SN1 reactions.
Lastly there are polar aprotic solvents. Some of the common polar aprotic solvents are acetone, ethyl acetate, tetrahydrofuran, diethyl ether and more. So when we have a polar aprotic solvent our nucleophile is not affected in the solution. It stays as strong nucleophile. So this means that polar aprotic solvents are very good for polar reactions; specifically nucleophilic substitution reactions. So polar aprotic solvents favor SN2 reactions.
Applications of industrial solvents
Industrial solvents have numerous benefits to a wide variety of industries. For example, solvents maintain tire durability and safety by gluing the different rubber layers together; they provide molecules to create drugs and also used for extraction and purification; they decrease the number of pesticides required by providing great spraying efficiency and optimal drying time. Even more, solvents improve performance on the slopes by binding various layers and generating powerful and durable skis. Also, solvents enable paints to be spread equally and reducing the amount used and of course they guarantee safety on the road by preventing the windscreen washer fluid from freezing in winter. You should know that solvents also used for industrial cleaning such as for aircraft engines or motor vehicle brakes.
One of the most important solvents is toluene. Toluene is excellent as a solvent because it can dissolve various numbers of organic compounds, unlike water. Toluene is used mainly in paint and coating industries. It is a huge part of making paints, paint thinners, adhesives, resins, glues, nail polish remover, correction fluid, inks and many more products that we use every day. Toluene even has a dangerous use in the explosives industry. It is one of the fundamental components of the explosive compound named TNT. But mainly toluene is known for its huge role in the paint and coating industry.
"Toseaye Pardis Sabz", the supplier of organic and inorganic pigments and materials, exports all kind of solvent based pigments that can be used in a wide range of products in different industries.
Source: R & D Unit of Toseaye Pardis Sabz