What is Organic Chemistry?

Organic Chemistry

Organic chemistry is all around us. The reactions and interactions of organic molecules allow us to see, smell, fight, and fear. Organic chemistry provides the molecules that feed us, treat our illnesses, protect our crops, and clean our clothes. Anyone with a curiosity about life and living things must have a basic under- standing of organic chemistry.

Historically, the term organic chemistry dates to the late 1700s, when it was used to mean the chemistry of compounds found in living organisms. Little was known about chemistry at that time, and the behavior of the “organic” substances isolated from plants and animals seemed different from that of the “inorganic” substances found in minerals.

Organic compounds were generally low-melting solids and were usually more difficult to isolate, purify, and work with than high-melting inorganic compounds. By the mid-1800s, however, it was clear that there was no fundamental difference between organic and inorganic compounds. The same principles explain the behaviors of all substances, regardless of origin or complexity. The only distinguishing characteristic of organic chemicals is that all contain the element carbon (Figure 1.1).

Figure 1.1 The position of carbon in the periodic table. Other ele- ments commonly found in organic compounds are shown in the colors typically used to represent them.

Why is carbon special?

Why, of the more than 37 million presently known chemical compounds, do more than 99% of them contain carbon? The answers to these questions come from carbon’s electronic structure and its consequent position in the periodic table.

As a group 4A element, carbon can share four valence electrons and form four strong covalent bonds. Further- more, carbon atoms can bond to one another, forming long chains and rings. Carbon, alone of all elements, is able to form an immense diversity of com- pounds, from the simple methane, with one carbon atom, to the staggeringly complex DNA, which can have more than 100 million carbons.

Not all carbon compounds are derived from living organisms of course. Modern chemists have developed a remarkably sophisticated ability to design and synthesize new organic compounds in the laboratory—medicines, dyes, polymers, and a host of other substances. Organic chemistry touches the lives of everyone; its study can be a fascinating undertaking.

Index of organic chemistry