Today I will post about conformational isomers, a class that belongs to the family of stereoisomers. This type of isomerism is somehow controversial, since there are people that consider it, indeed, as a particular type of isomerism, while others consider that we are talking about different structures of the same molecule.
In order to understand the concept of conformational isomer, it is recommended to highlight a property that is observed only in single bounds – its capacity to rotate, functioning as an axis.
In this context, regions of a molecule that contain single bounds are characterized by their high rotational flexibility.
When two molecules are compared, if it is possible to convert one in the other through rotation on one (or more) single bounds, they are conformational isomers.
Since, in fact, the two molecules are converted without the need to break or create new covalent bonds (this is the definition of conformation, as it was explained here in a previous post…), there are people that claim that those molecules don’t have to be considered isomers.