Overview of Organic Chemistry: Hydrocarbons and Aromatics

Overview of Organic Chemistry: Focus on Hydrocarbons and Aromatics

Organic chemistry deals with carbon-based compounds, particularly those derived from petroleum, coal, natural gas, plants, animals, minerals, fungi, bacteria, and synthetic sources. It involves studying their structure, properties, composition, configurations, preparation, reactions, physical transformations under the influence of heat or light, and the effects of electric currents or other energies on them.

In this article, we will focus on two important aspects of organic chemistry: hydrocarbons and aromatics.

Hydrocarbons

Hydrocarbons are organic compounds composed solely of hydrogen and carbon atoms. They can be classified into different types depending on the number of carbon atoms connected directly to hydrogen atoms:

• Alkanes have single bonds only, making them saturated hydrocarbons without double or triple bonds. Examples include methane (CH₄), ethane (C₂H₆), propane (C₃H₈), and butane (C₄H₁₀).
• Alkenes contain one or more carbon-to-carbon double bonds. For instance, ethene (C₂H₄) contains a central double bond while propene (C₃H₆) contains an end double bond.
• Alkynes feature carbon-to-carbon triple bonds, like acetylene (C₂H₂) where both ends are joined together by triple bonds.

These classes differ in reactivity due to differences in bond strength and bond angle. Additionally, the presence of unsaturated bonds in alkenes and alkynes makes these compounds more susceptible to addition and substitution reactions compared to alkanes.

Aromatics

Aromatic compounds are characterized by the presence of a system of alternating single and double bonds in a planar ring. Examples of aromatic hydrocarbons include benzene (C₆H₆), naphthalene (C₁₀H₈), anthracene (C₁₄H₁₀), and phenanthrene (C₁₇H₁₂). The special arrangement of pi electrons leads to resonance, stability, and unique electronic properties. Aromatic compounds tend to form stable compounds with various electrophiles because of the delocalization of the pi electrons over the entire ring. Furthermore, they often participate in Friedel-Crafts reactions, nitration, sulfonation, halogenation, and polyhalogenation reactions.

Researchers continue to investigate and develop new synthetic routes to produce specific hydrocarbons and aromatics. Understanding these fundamental building blocks helps us understand and predict the behavior of larger molecules in reactions, helping drive innovation across numerous industries.