8.1. General Introduction

Organic compounds are vital for sustaining life on earth and include complex molecules like genetic information bearing deoxyribonucleic acid (DNA) and proteins that constitute essential compounds of our blood, muscles and skin. Organic compounds appear in materials like clothing, fuels, polymers, dyes and medicines. These are some of the important areas of application of these compounds.

Organic compounds play a crucial role in life and a wide range of materials we use daily. For instance, DNA, which carries genetic information, is an organic compound. Proteins, which are essential for bodily functions, are made of organic compounds. Furthermore, many everyday items like clothing, fuels, and medicines are based on organic chemistry. This illustrates how organic compounds are not just theoretical but foundational to life and industry.

Think of organic compounds as the building blocks of life, just as bricks are critical for building a house. Just as a house relies on bricks for its structure, life relies on organic compounds for its existence. Without DNA and proteins, life as we know it wouldn't be possible.

Science of organic chemistry is about two hundred years old. Around the year 1780, chemists began to distinguish between organic compounds obtained from plants and animals and inorganic compounds prepared from mineral sources. Berzilius, a Swedish chemist proposed that a ‘vital force’ was responsible for the formation of organic compounds. However, this notion was rejected in 1828 when F. Wohler synthesised an organic compound, urea from an inorganic compound, ammonium cyanate.

The field of organic chemistry has evolved over approximately two centuries. Initially, scientists believed that organic compounds could only originate from living organisms, a view dominated by the concept of 'vitalism'. However, in 1828, Friedrich Wohler's synthesis of urea from an inorganic precursor, ammonium cyanate, shifted this perspective radically, demonstrating that organic compounds could be synthesized in the laboratory without the need for a 'vital force'. This discovery laid the groundwork for modern organic chemistry.

Imagine believing that you need special magic to create a particular dish, like a cake. Once you discover that you can bake a cake with simple ingredients like flour and eggs, without any magic, it changes how you think about baking. Wohler's experiment was similar – it transformed chemistry by proving that organic chemistry doesn't require any mystical forces, just chemistry itself.

The pioneering synthesis of acetic acid by Kolbe (1845) and that of methane by Berthelot (1856) showed conclusively that organic compounds could be synthesised from inorganic sources in a laboratory.

The successful synthesis of acetic acid and methane represented significant milestones in organic chemistry, reinforcing the idea that organic substances could be derived from inorganic materials. Kolbe's synthesis of acetic acid and Berthelot's synthesis of methane challenged existing notions by proving that even complex compounds could be generated through chemical reactions in laboratory settings rather than only being derived from biological sources.

Think of a chef who can create a meal from raw ingredients. Kolbe and Berthelot were like chefs in a chemistry lab, showing that, with the right techniques and ingredients, they could prepare 'meals' – organic compounds – from basic materials, just as a chef uses vegetables and spices to create a delicious dish.

The development of electronic theory of covalent bonding ushered organic chemistry into its modern shape.

The understanding of covalent bonding through the lens of electronic theory greatly advanced the field of organic chemistry. This theory provided insights into how atoms bond and interact, leading to a deeper comprehension of molecular shapes, reactivity, and the overall behavior of organic compounds. This knowledge is foundational for various applications in chemistry, biology, and material science.

Consider how knowing the recipe and techniques changes your cooking. In the same way, the development of electronic theory offered chemists a 'recipe' for understanding how different compounds interact and form, thus revolutionizing their approach and enabling the creation of newer materials and medicines.

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