Dative Bond Definition (Coordinate Bond)

A covalent bond forms when two atoms share electrons. The electron pair is attracted to both atomic nuclei, holding them together to form a bond. In a typical covalent bond, each atom supplies an electron to form the bond. A dative bond is a covalent bond between two atoms where one of the atoms provides both electrons that form the bond. A dative bond is also known as a dipolar bond or coordinate bond. In a diagram, a dative bond is indicated by drawing an arrow pointing from the atom that donates the lone electron pair toward the atom that accepts the pair. The arrow replaces the usual line that indicates a chemical bond. Key Takeaways: Dative Bond A dative bond is a 2-center, 2-electron covalent bond in which both electrons come from the same atom.A dative bond is also called a coordinate covalent bond or a coordinate bond.Dative bonds are common when metal ions bind to ligands. Dative Bond Example Dative bonds are commonly seen in reactions involving hydrogen (H) atoms. For example, when hydrogen chloride dissolves in water to make hydrochloric acid, a dative bond is found in the hydronium ion: H2O HCl → H3O Cl- The hydrogen nucleus is transferred to the water molecule to form hydronium, so it does not contribute any electrons to the bond. Once the bond is formed, there is no difference between a dative bond and an ordinary covalent bond. Source Greenwood, Norman N.; Earnshaw, Alan. Chemistry of the Elements (2nd ed.). Butterworth-Heinemann, 1997, Oxford.