Constitutional (structural) isomers
Constitutional (structural) isomers are compounds that have the same molecular formula but a different atom-to-atom bonding sequence. Since constitutional isomers have different physical properties, usually they can be separated easily from each other .
(1)
(2)
(4)Constitutional (structural) isomers may have different functional groups.
Constitutional isomers of C5H10O2 are used below to illustrate different atom-to-atom bonding sequences.
(1)
(2)
Constitutional (structural) isomers may have the same functional group and the same carbon skeleton (The carbon skeleton shows the arrangement of carbon atoms.), but the functional group is attached to a different carbon atom.
(3)
Examples of this type are the constitutional isomers (1) and (2).
This type of constitutional isomerism is also known as positional isomerism.
This type of constitutional isomerism is also known as positional isomerism.
(3)
Constitutional (structural) isomers may have the same functional group and different carbon skeletons.
Constitutional isomer (3) is a C5H10O2 isomer with a carbon skeleton different from those of (1) and (2).
Constitutional isomers that have different carbon skeletons are also known as chain isomers.
Constitutional isomers that have different carbon skeletons are also known as chain isomers.
(4)
Constitutional isomers that have different functional groups are also known as functional group isomers.
Constitutional isomer (4) is a functional group isomer of the constitutional isomers (1), (2) and (3).
Constitutional isomer (4) is a functional group isomer of the constitutional isomers (1), (2) and (3).