Inter-molecular Electron Repulsion

[Suraj Doshi 2G]

When discussing repulsion strength between regions of electron density and atoms, how can we determine which repulsion forces (ie lone-lone PR, lone-bonding PR, bonding-bonding PR) are the strongest?

[Luyan Zhang - 2D]

Lone pair-lone pair > Lone pair-bonding pair > bonding pair-bonding pair

I think you will just have to remember this.

[Gwen Casillan 3E]

The repulsion forces in order of least to most strong are:
bonding-bonding pr < lone-bonding pr < lone-lone pr

[Justin Quan 4I]

Lone pair-lone pair > Lone pair-bonding pair > bonding pair-bonding pair

Lone pair-lone pair have the most repulsion force because of the shape of the electron density. The lone pair e- are more closer together, so they have stronger forces.

[Shivam Rana 1D]

You can also think of strength by how diffuse each type of pair is. Therefore, because the lone pair is the most diffuse, it is the most repulsive. Lone pairs also have lower effective nuclear charge acting on them.

[RRahimtoola1I]

What is an example of a lone-bonding pair?

[EthanPham_1G]

An example of a lone pair-bonding pair repulsion would be sulfur tetrafluoride, SF4. It has 5 areas of electron density: 4 bonding pairs and 1 lone pair. The lone pair on the central sulfur atom repels the four bonding pairs and reduces the bond angle.