# Ionic bonding question about "double" ionic bonds

Is a "double" ionic bond (the transfer of two electrons) like in MgO any stronger (or really any different, structurally etc.) than a "single" ionic bond (the transfer of one electron) like in NaCl?

chemisttree
Homework Helper
Gold Member
Yes it is. Doubling the ionic charge nearly quadruples the bond energy.

ProjectFringe
Borek
Mentor
Ionic bonds are mostly about simple Coulomb forces, these are quite easy to estimate with

$$F = k\frac{q_1q_2}{r^2}$$

Just try to put what you wrote into the equation and you will see where @chemisttree answer comes from.

ProjectFringe
Is it possible then to make NaCl with a double ionic bond by combining in a lab Cl+ and Na-? Does this compound exist and if so what is it called (how to differentiate from normal NaCl)?

Borek
Mentor
No, you can't make a double bond out of single charged ions.

And you can't ionize Na nor Cl further - that is, in some exotic conditions you can, but when you combine them the Na2+ will steal an electron from Cl2- and they will live happily ever after in their local energetic optimum.

ProjectFringe
Got it. Thanks

No, you can't make a double bond out of single charged ions.

And you can't ionize Na nor Cl further - that is, in some exotic conditions you can, but when you combine them the Na2+ will steal an electron from Cl2- and they will live happily ever after in their local energetic optimum.
Sorry, one more question.

What reaction would occur between Cl2 and a Na-? Would a Cl atom steal an electron from Na, making Cl- + NaCl? Or would the Na- create an ionic bond with both Cl atoms creating a structure similar to MgCl2?

Sorry, one more question.

What reaction would occur between Cl2 and a Na-? Would a Cl atom steal an electron from Na, making Cl- + NaCl? Or would the Na- create an ionic bond with both Cl atoms creating a structure similar to MgCl2?

Actually, I was able to find both compounds here:

https://pubchem.ncbi.nlm.nih.gov/compound/22590707

https://pubchem.ncbi.nlm.nih.gov/compound/57736105

So, what makes the difference between which of these compound structures is formed, or are they the same thing?

Borek
Mentor
Sodium dichloride (assuming it exists) is not Na- + Cl2, if anything, I would treat it as Na+ + 2Cl-.

ProjectFringe