Iodomethane (also known as methyl iodide or CH3I) is a kind of alkyl halide. It is naturally emitted by rice plantations in small amounts, and produced in vast quantities estimated to be greater than 214,000 tons annually by algae and kelp in the world’s temperate oceans, as well as by terrestrial fungi and bacteria[2, 3].

It is used in organic synthesis to produce methyl groups. It is also used in the preparation of methylmagnesium chloride and for certain pharmaceuticals.

The boiling point of iodomethane is about twice that of methane, and it has a lower vapor pressure than MeBr. This makes it less likely to volatilize from dry soil surfaces than MeBr.

This is because iodomethane is very non-polar, and it has relatively few dipole-dipole attractions between its molecules. However, it does have dispersion forces and hydrogen bonds between water molecules. It is a large molecule and so its London dispersion forces are significantly larger than those of HF, which is also very non-polar.

In this situation the dispersion forces are much more important than the dipole-dipole attractions. Nevertheless, they are still not enough to explain why the boiling point is so high for iodomethane.

It is important to remember that iodomethane has both van der Waals dispersion forces and dipole-dipole interactions, which are much weaker than hydrogen bonds between water molecules. So it is important to keep this in mind when discussing the boiling point of iodomethane.