heteroatome

Heteroatom is a term used in chemistry to describe an atom that does not belong to the group of atoms typically classified as carbon and hydrogen. This group usually consists of atoms from the first and second columns of the periodic table, such as hydrogen, carbon, and nitrogen. However, heteroatoms refer to atoms from other parts of the periodic table, including oxygen, sulfur, phosphorus, and metals.

Heteroatoms can play various roles in molecules, including being part of covalent bonds, occupying electron pairs, and contributing to molecular polarity. Their presence can greatly affect the properties and reactivity of molecules, such as water and sugar. For instance, the oxygen atom in a water molecule (H2O) determines its solubility in organic solvents. In the case of sugar, the presence of a heteroatom like oxygen is responsible for its sweet taste.

Organic molecules can contain different types of heteroatoms, which can be classified into two groups: isosteric and non-isosteric heteroatoms. Isosteric heteroatoms replace one or more hydrogen atoms within a functional group, forming comparable carbon-based molecules. Non-isosteric heteroatoms, in contrast, replace a hydrogen atom in a non-functional group, resulting in structurally different molecules. Examples of heteroatoms include halogens (chlorine, bromine, and iodine) and pseudo-halogens (oxygen, nitrogen, and sulfur).

The incorporation of heteroatoms into molecules via chemical synthesis is often sought after, especially in pharmaceutical and highly technical applications. Selective replacement of hydrogen with heteroatoms can significantly alter the molecular properties, leading to novel compounds with specific characteristics.