As an organic chemistry student studying substitution and elimination reactions, one of the topics that you will face on a regular basis is the classification of solvents. In this article I will show you how to recognize the different solvent types to that you can comfortably apply them to your SN1 SNE E1 E2 reactions Solvents fall into 3 main categories. Polar Protic Solvents, Polar Aprotic Solvents, Non-Polar Solvents
Both of the solvents mentioned start with the word 'polar'. Therefor it is important for you to understand the polarity of a solvent and how it relates to reactions. Polar, comes from the word 'pole' meaning opposites. This occurs when you have a neutral molecule, however there is a concentration of negative charge on one end, and a concentration of positive charge on another end of the molecule. This happens when there is a covalent bond between solvent atoms but instead of equal sharing, one of the atoms pulls the electrons towards itself thus concentrating the negative charge on that portion of the molecule. The atom from which the electrons were pulled winds up the positive 'pole' or portion of the molecule
The word protic, in polar protic solvents, comes from the word proton, which is simply the positive nucleus of a hydrogen atom. When hydrogen is bound to a very electronegative atoms like N, O or F, these atoms form polar covalent bonds that are so extreme, to the point where not only is hydrogen partially positive, but its entire nucleus is exposed. Since the nucleus of hydrogen contains one proton, the exposed proton makes the solvent protic. If another highly electronegative atom like N, O or F comes across this protic hydrogen, it will attempt to make a bond, called a hydrogen bond. Examples of polar protic solvents include water and ammonia
Polar aprotic solvents tend to be the most confusing. While the solvent molecules do have partial charges or polarity, they are incapable of hydrogen bonding. this is because the polarity typically does not occur between a hydrogen and nitrogen, or hydrogen and oxygen atom.
A common example is the solvent acetone, also known as propanone. This condensed molecular formula for the polar aprotic acetone is CH3C=OCH3. Notice that the pi bond (double bond) between carbon and oxygen will result in a partial positive pole on the carbon and a partial negative pole on the oxygen. However, there are no H atoms on the oxygen. Instead the only H atoms on this molecule are found on carbon. This bond is non-polar covalent and will not allow the solvent to hydrogen bond
Both of the solvents mentioned start with the word 'polar'. Therefor it is important for you to understand the polarity of a solvent and how it relates to reactions. Polar, comes from the word 'pole' meaning opposites. This occurs when you have a neutral molecule, however there is a concentration of negative charge on one end, and a concentration of positive charge on another end of the molecule. This happens when there is a covalent bond between solvent atoms but instead of equal sharing, one of the atoms pulls the electrons towards itself thus concentrating the negative charge on that portion of the molecule. The atom from which the electrons were pulled winds up the positive 'pole' or portion of the molecule
The word protic, in polar protic solvents, comes from the word proton, which is simply the positive nucleus of a hydrogen atom. When hydrogen is bound to a very electronegative atoms like N, O or F, these atoms form polar covalent bonds that are so extreme, to the point where not only is hydrogen partially positive, but its entire nucleus is exposed. Since the nucleus of hydrogen contains one proton, the exposed proton makes the solvent protic. If another highly electronegative atom like N, O or F comes across this protic hydrogen, it will attempt to make a bond, called a hydrogen bond. Examples of polar protic solvents include water and ammonia
Polar aprotic solvents tend to be the most confusing. While the solvent molecules do have partial charges or polarity, they are incapable of hydrogen bonding. this is because the polarity typically does not occur between a hydrogen and nitrogen, or hydrogen and oxygen atom.
A common example is the solvent acetone, also known as propanone. This condensed molecular formula for the polar aprotic acetone is CH3C=OCH3. Notice that the pi bond (double bond) between carbon and oxygen will result in a partial positive pole on the carbon and a partial negative pole on the oxygen. However, there are no H atoms on the oxygen. Instead the only H atoms on this molecule are found on carbon. This bond is non-polar covalent and will not allow the solvent to hydrogen bond
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See many common examples of these organic solvents by watching my youtube tutorial video on this topics
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