Hi Natasha,

A coordinate covalent bond is a defined as a covalent bond where both electrons come from one of the atoms involved in the bond.

ex) Cl --> Fe (both electrons came from the Cl-)

It is distinct from a regular covalent bond where one electron came from each atom.

A lewis acid/base reaction involves the acceptance of an electron pair (lewis acid) with the concomitant donation of an electon pair by a lewis base. This describes a reaction while the coordinate covalent bond describes the nature of the compound.

However, the formation of coordinate covalent bonds by definition will involve a lewis acid and lewis base.

There is no such thing as an ionic coordinate bond.

Please let me know if you would like more clarification.

Katt