Fundamentals of Organic Chemistry | Naming Organic compounds

What is ORGANIC CHEMISTRY???

Organic chemistry is one of the most fundamental and widely used branches of chemistry that deals with the study of hydrocarbons and their derivatives. It explains the structure of the molecule in detail with an analysis of properties in a proper way. In other words, I can say that organic chemistry best way to connect and study molecules and their properties.

 

Carbon is the main constituent of organic compounds. It forms stable bonds with many other elements such as H, F, Cl, Br, I, N, P, S, etc. Carbon atoms form different types of structures depending on the number of carbon atoms. 

These structures may be long chains of carbon, branched chains, rings, chiral (optical property), or complex 3D molecules.

The Organic compounds are held together with the chemical bond linkage that is covalent bonding. Covalent bonding refers to the mutual sharing of electrons between different atoms.

The carbon atom has four valencies that’s why it has the tendency to form four bonds and is sp3 hybridized. (more about orbital hybridization)

The molecules or compounds that we study in Organic compounds are derived from natural or living resources. Moreover, these compounds are being used in our daily life as well as for medicinal purposes. 

Complex organic substances can perform a wide range of biological tasks that are investigated in biochemistry. These complex molecules include vitamins, carbohydrates, lipids, proteins, enzymes, ATP, DNA, and RNA. 

Importantly, the studies of natural products and their use are the major direction of research nowadays. So, to study organic chemistry properly, we need to understand the following aspects.

• The structural concepts and bonding in molecules

The structural concepts involve the types of chemical bonding between atoms and molecules, which can be Ionic (based on the electrostatic potential of oppositely charged ions) or covalent ( based on the mutual sharing of electrons between atoms) bonding. 

Lewis structure of atoms, formation of double and triple bonds between atoms, polarity and non-polar nature of molecules, resonance and inductive effects are all important concepts to understand the properties of organic compounds.

There are different important models/methods to understand the shape, geometry, and bonding in molecules such as,

1. VSEPR theory

1. Valence Bond Theory (VBT)

1. Molecular Orbital Theory (MOT) 

• Nomenclature of Organic compounds

The nomenclature of organic compounds uses the IUPAC ( International union of pure and applied chemistry) system of naming the compounds. It has different rules for different classes of compounds. 

• Mentioned below are the major rules for the nomenclature of organic compounds:

1. First of all, we locate the longest chain of carbon atoms in the molecule
2. We name the longest carbon chain by carbon atom using the prefix as shown below in the diagram.  
3. Identify the functional group and add suffixes.
4. Identify the side groups by considering both sides of the carbon chain, and choose that side from where the side group approaches at first. The first carbon is considered the carbon with a side group presence.
5. In the last, we have to name that side group, and here's the nomenclature done. 

                      

• Stereochemistry 

 Stereochemistry refers to the arrangement of elements in space and their impact on physical and chemical properties. The connection between two different molecules formed with similar atoms is understood with the help of stereochemistry. Moreover, we can understand the biological properties of molecules. 

The compounds having the same molecular formula but different arrangements of atoms in 3-dimensional space are known as stereoisomers. 

There are two types of stereoisomers: Diastereomers and Enantiomers.

Diastereomers are superimposable mirror images, that are not enantiomers.

Enantiomers are non-super-imposable mirror images. Or we can say that the chiral molecules with are mirror mages of each other are enantiomers.  

Meso forms exist in molecules containing stereocenters that are symmetric/ achiral. Such compounds and their mirror images are not stereoisomers, and are identical to each other, these compounds are known as Meso compounds.

Some common terms used in stereochemistry:

Chiral carbon: The carbon atom containing four different substituents attached to it. Also known as Asymmetric carbon. Carbon is considered a common stereocenter/ chirality center.

Optical activity: It is the ability of chiral compounds that can rotate the plane of polarized light. If the plane of polarized light is rotated to the right it is Dextrorotatory. Or if the plane of polarized light is rotated to the left it is Levorotatory.

Racemic mixture: The mixture that contains equal amounts of enantiomers, has no optical activity due to the presence of equal enantiomers.

• Organic compounds

• Hydrocarbons (Alkanes, Alkenes, and Alkynes)

• Alkyl halides

• Carbonyl Compounds

• Carboxylic Acids

• Alcohols and Phenols

• Nitrogen-containing compounds

• Organometallic compounds