Carbon dioxide is not an organic compound

Organic compounds are molecular compounds based on the chemistry of carbon and, in addition to this element, they may contain other non-metals such as hydrogen, oxygen, nitrogen, sulfur, phosphorus and halogens. Given that carbon dioxide or carbon dioxide (CO ₂ ) is a molecular gas made up of oxygen and carbon, it is natural to wonder whether or not it is an organic compound.

The short answer to this question is that it is not. The long answer requires that we understand precisely what it means to be an organic compound; that is, we must be clear about the definition of an organic compound in order to be able to determine what are the characteristics of carbon dioxide that make it an inorganic compound.

How is an organic compound defined?

Classic definition of organic compound

Until the first quarter of the 19th century , any substance from living beings, provided with a vital energy that did not allow it to be synthesized from inorganic substances such as salts, minerals and other compounds, was considered an organic compound .

This was the rule followed by chemists for many years. From this point of view, carbon dioxide does not meet the requirements to be considered an organic compound, since there are many inorganic substances that can be transformed into carbon dioxide. Examples of this are mineral carbon, graphite and other allotropic forms of this element, which are obviously inorganic; however, they quickly turn into carbon dioxide when burned in the presence of oxygen.

The modern concept of organic compound

The earlier concept of an organic compound held firm until the German chemist Friedrich Wöhler demonstrated the error of this hypothesis by synthesizing a clearly organic compound (urea) from three substances considered to be inorganic, namely lead cyanate ( II), ammonia and water. The reaction of the Wöhler synthesis was:

This incontrovertible evidence forced chemists to look for other characteristics that were common to what they considered to be organic compounds and to reconsider that concept. Today an organic compound is considered to be any molecular chemical substance that possesses one or more carbon-hydrogen (CH) covalent bonds. It can also contain CC, CO, CN, CS and other bonds, but the condition without which it cannot be recognized as an organic compound is that it has CH bonds.

The carbon dioxide molecule is made up of a central carbon atom that is linked, by means of double covalent bonds, to two oxygen atoms that point in opposite directions. By studying its composition, it is quickly concluded that carbon dioxide does not have CH bonds (in fact, it does not even contain hydrogen), so it cannot be considered an organic compound.

Other carbon-based compounds that are also non-organic

In addition to carbon dioxide, there are many other compounds of synthetic origin or not. Some of them are:

• The allotropes of carbon (graphite, graphene, mineral carbon, etc.).
• Sodium carbonate.
• Sodium bicarbonate.
• carbon monoxide.
• carbon tetrachloride.

Conclusion

Carbon dioxide is not considered an organic compound because it does not have carbon-hydrogen bonds. This despite having carbon and oxygen, another of the elements that are part of organic compounds.

References

Saltzman, Martin D. “Wöhler, Friedrich.” Chemistry: Foundations and Applications . Encyclopedia.com. https://www.encyclopedia.com/science/news-wires-white-papers-and-books/wohler-friedrich