Which of the following will show geometrical isomerism?
Which of the following will show geometrical isomerism?
The correct option is D CH3CH=NOH
Isomers are molecules that have the same molecular formula but have a different arrangement of the atoms in space. That excludes any different arrangements which are simply due to the molecule rotating as a whole, or rotating about particular bonds. Where the atoms making up the various isomers are joined up in a different order, this is known as structural isomerism. Structural isomerism is not a form of stereoisomerism; in stereoisomerism, the atoms making up the isomers are joined up in the same order, but still manage to have a different spatial arrangement. Geometric isomerism is one form of stereoisomerism.
Geometric (cis / trans) isomerism
These isomers occur where you have restricted rotation somewhere in a molecule. This could involve carbon single bonds (like in trans-1,2-dicyclopentane) or carbon double bond - like shown above. (E)-cyclodecene is already in a fixed configuration. The carbon-nitrogen double bond won't rotate and so you would have to take the models to pieces in order to convert one structure into the other one. That is a simple test for geometrical isomerism. If you have to take a model to pieces to convert it into another one, then you've got geometrical isomers.
CH3CH=NOH
Isomers are molecules that have the same molecular formula but have a different arrangement of the atoms in space. That excludes any different arrangements which are simply due to the molecule rotating as a whole, or rotating about particular bonds. Where the atoms making up the various isomers are joined up in a different order, this is known as structural isomerism. Structural isomerism is not a form of stereoisomerism; in stereoisomerism, the atoms making up the isomers are joined up in the same order, but still manage to have a different spatial arrangement. Geometric isomerism is one form of stereoisomerism.
Geometric (cis / trans) isomerism
These isomers occur where you have restricted rotation somewhere in a molecule. This could involve carbon single bonds (like in trans-1,2-dicyclopentane) or carbon double bond - like shown above. (E)-cyclodecene is already in a fixed configuration. The carbon-nitrogen double bond won't rotate and so you would have to take the models to pieces in order to convert one structure into the other one. That is a simple test for geometrical isomerism. If you have to take a model to pieces to convert it into another one, then you've got geometrical isomers.
