what sre ‘non resolvable’ isomers

Interconversion is the characteristic of nearly every set of conformational isomers which are also stereoisomers as they also differ in the way their atoms are orientated in space.But in case of stereoisomers interconvertibility is of great practical significance as it limits their isolability.Stereoisomers are of two types-
1.Hard -to- interconvert and
2. Easy-to- inetconvert
Hard-to interconvert isomers can be separated,,studied individually and their optical activity can be measured.But easy to inerconvert can not be separated,single isolated isomers cannot be studied and optical activity cannot be observed.Since any such chiral molecules are present only as non-resolvable racemic modifications.Such isomers that cannot be separated are reffered to as non-resolvable isomers.

Non resolvable compounds include:1)symmetrical comp.Eg:benzene, CH42)Meso3)Topomerisation(Interconvertible enantiomers):~amine inversion~carbanion~ring flip