What is a coordinate covalent bond?

A coordinate covalent bond is a type of chemical bond where both bonding electrons come from the same atom.

In more detail, a coordinate covalent bond, also known as a dative bond, is a special type of covalent bond. In a typical covalent bond, each atom contributes one electron to the bond. However, in a coordinate covalent bond, one atom provides both electrons. This usually happens when a molecule or ion has a lone pair of electrons that another atom can accept to achieve a stable electron configuration.

The atom that donates the pair of electrons is known as the donor atom, while the atom that accepts the electrons is referred to as the acceptor atom. The donor atom is usually a nonmetal, while the acceptor atom can be either a nonmetal or a metal.

It's important to note that once the bond is formed, it behaves like any other covalent bond. This means that the electrons are shared between the two atoms, and there is no difference in the physical or chemical properties of the bond compared to a regular covalent bond.

Coordinate covalent bonds are commonly found in many types of molecules and ions, including ammonium ions, hydronium ions, and boron trifluoride. They also play a crucial role in many biological processes, such as the formation of haemoglobin in red blood cells.

Understanding coordinate covalent bonds is essential in chemistry because they help explain the behaviour and properties of many molecules and ions. They also provide insight into the nature of chemical bonding and the role of electrons in these processes.