Dative bonding

Dative means to donate.

  • In an ordinary covalent bond 1 electron is shared from each atom
  • In a dative covalent bond, one atom provides both of the electrons

A good example of this is the ammonium ion.

Starting with ammonia.

 

The non-bonding pair can be donated of another atom, ion or molecule is able to accept it.

This donated bond is identical to any other non-donated bond.

  • Life itself depends on the ability of certain compounds like water and ammonia to carry out this altered version of bonding.
Can be written as:

To acknowledge the dative bond.

Okay, so what about another example?

BF3 (boron trifluoride) and ammonia can undergo dative bonding. This is the standard other example that is often quoted.

BF3 is electron deficient like most boron compounds (in fact boron can create single electron bonds).

As boron does not have a full outer shell, it is able to accept an electron pair from ammonia.