Question

What is a coordinate covalent bond, and how does it diff from a covalent bond?

Short answer

A coordinate covalent bond differs from a covalent bond as it involves one atom donating both electrons in the bond.

Step-by-step solution

Understanding Covalent Bonding

A covalent bond is formed when two atoms share one or more pairs of electrons. In this type of bond, each atom typically provides one electron to form the electron pair that is shared by the bonded atoms.

Introducing Coordinate Covalent Bond

In a coordinate covalent bond, also known as a dative bond, both shared electrons in the bond pair are donated by one of the atoms. This is different from the typical covalent bond where each atom contributes one electron.

Identifying Key Differences

The main difference between a coordinate covalent bond and a covalent bond is the source of the electrons. In coordinate covalent bonds, one atom provides both electrons for the bond, while in covalent bonds, each atom provides one electron.

Key concepts

covalent bonding

Covalent bonding is a fundamental concept in chemistry that describes how atoms bond together by sharing pairs of electrons. This process allows each atom to achieve a more stable electron configuration, similar to that of noble gases.
A typical covalent bond occurs when each of the two atoms contributes one electron to form a shared pair. This can be visualized as two overlapping electron clouds or orbitals, where the shared electrons spend time in close proximity to both atomic nuclei.
The strength of a covalent bond depends on the number of shared electron pairs and the specific atoms involved. Some common features of covalent bonding include:

• Electronegativity: Atoms with similar electronegativity values tend to form covalent bonds.
• Types of Bonds: Single, double, and triple bonds can form, depending on how many electron pairs are shared.
• Molecular Structure: Covalent bonds contribute to the formation of molecules with specific 3D shapes, affecting their physical and chemical properties.

electron sharing

Electron sharing is a key component of covalent bonding. Through this process, atoms share one or more pairs of electrons, allowing them to fill their outermost electron shells, or valence shells.
This desire to achieve a full valence shell is known as the octet rule, where most atoms strive to have eight electrons in their outer layer, similar to the electron configuration of a noble gas.
But, not all shared electrons are involved equally. The sharing can be:

• Equal Sharing: Occurs in non-polar covalent bonds where electrons are shared equally between atoms with similar electronegativity.
• Unequal Sharing: Happens in polar covalent bonds with atoms having different electronegativity, resulting in partial positive and negative charges within the molecule.

Understanding electron sharing helps predict the polarity, reactivity, and interactions of molecules.

dative bond

A dative bond, also referred to as a coordinate covalent bond, is a unique type of covalent bond. In this bond, both electrons in the shared pair originate from the same atom. This differs from a typical covalent bond where each atom in the bond supplies one electron.
This can be visualized when one atom has a lone pair of electrons and another atom is electron-deficient. The atom with the lone pair "donates" both of its electrons to form the bond.
The distinct characteristics of dative bonds include:

• Lone Pair Donation: Often involves a lone pair of electrons from a donor atom.
• Complex Formation: Commonly seen in coordination complexes and molecule formation like ammonium ion (NH₄⁺).
• Reversibility: Can often be reversible, where the bonded state can be undone if conditions change.

This bond type is important for understanding the behavior of molecules and ions in various chemical reactions.