Can London dispersion forces be repulsive?

Abstract: Large substituents are commonly seen as entirely repulsive through steric hindrance. Such groups have addi- tional attractive effects arising from weak London dispersion forces between the neutral atoms. DFT computations revealed that attractive dispersion forces essentially lower the energy of the Z isomers.

Can dispersion forces be repulsive?

The induction and dispersion interactions are always attractive, irrespective of orientation, but the electrostatic interaction changes sign upon rotation of the molecules. That is, the electrostatic force can be attractive or repulsive, depending on the mutual orientation of the molecules.

Do London dispersion forces attract or repel?

The London Dispersion force is caused by the formation of temporary dipoles in the electron cloud of neutral atoms that attract each other.

Why are London dispersion forces the weakest?

It is the weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules. This force is weaker in smaller atoms and stronger in larger ones because they have more electrons that are farther from the nucleus and are able to move around easier.

What affects London dispersion forces?

Generally, London dispersion forces depend on the atomic or molecular weight of the material. Heavier atoms or molecules have more electrons, and stronger London forces. This means that they are harder to melt or boil. This explains the states of the halogen molecules at room temperature.

What substances have only London dispersion force?

Non-polar particles such as Argon, Hydrogen gas, Fluorine gas and Methane only have London dispersion forces in between their atoms or molecules.

Are London forces polar or nonpolar?

London forces are the attractive forces that cause nonpolar substances to condense to liquids and to freeze into solids when the temperature is lowered sufficiently.

What causes London dispersion forces?

The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. Dispersion forces are present between any two molecules (even polar molecules) when they are almost touching.