What is smell and what determines the smell of a product in a molecule?

Answer

Dear Abid,

On wikipedia you will find a very clear explanation about smell, but that is a little less about your specific question about the property of the molecule.

In fact, it is not known exactly which property of a molecule gives rise to an odor. Research is being carried out there https://www.eosscience.eu/science/give-me-een-molecule-en-ik-zeg-u-hoe-ze-smeekt.

I can tell you that terpenes (ie a group of alkenes, ie molecules with carbon atoms and conjugated double bonds, ie alternating single and double bonds) are well known for their wonderful smells. You can find these substances in the peel of oranges (limonene). So here there seems to be a connection between the structure of the binding and the property of the smell. https://www.canoil.nl/blogs/blog/wat-zijn-terpenen-hoe-belangrijk-zijn-terpenen-en/

Another group of molecules, the esters, are known for their sweet smell, so they also have a characteristic group.

The presence of the S-atom (sulphur) usually gives off a foul odor.

It is important that the molecule is in the gas phase, otherwise it has no odor.

Kind regards,

Els Van Mechelen