It doesn't matter where the electrons came from; they are shared between the atoms the same as if it is a coordinate covalent bond, a " normal " bond, or from some sort of electrochemistry.
12.
The Co-Cl bonds ( in the above example ) are now classed as ionic, and each Co-N bond is a coordinate covalent bond between the Lewis acid Co 3 + and the Lewis base NH 3.
13.
For example, the ion Ag + reacts as a Lewis acid with two molecules of the Lewis base NH 3 to form the complex ion Ag ( NH 3 ) 2 +, which has two Ag?! N coordinate covalent bonds.
14.
In the diamond-like structure, called cubic boron nitride ( tradename Borazon ), boron atoms exist in the tetrahedral structure of carbons atoms in diamond, but one in every four B-N bonds can be viewed as a coordinate covalent bond, wherein two electrons are donated by the nitrogen atom which acts as the Lewis base to a bond to the Lewis acidic boron ( III ) centre.
