Constitutional isomers with different functional groups

Two compounds can have different structures because of a differing arrangement of the some groups in the positional isomerism (e.g. midine vs. pseudouridine). Compounds with the same molecular formula but with different functional groups are structural isomers (e.g. D-glucose vs. D-fructose) in structural isomerism. Positional isomers and structural isomers have different chemical and physical properties because of the different arrangement of the atoms. These two types of isomers (i.e. positional isomers and structural isomers), which differ in the manner in which atoms are connected or bonded together, are also called constitutional isomers. 

Constitutional isomers are molecules with different connectivities between the atoms. Either the structures have different functional groups (these are called structural isomers), or the same functional group is placed in different positions (positional isomers). 

Constitutional isomerism is not limited to alkanes—it occurs widely throughout organic chemistry. Constitutional isomers may have different carbon skeletons (as in isobutane and butane), different functional groups (as in ethanol and dimethyl ether), or different locations of a functional group along the chain (as in isopropylamine and propylamine). Regardless of the reason for the isomerism, constitutional isomers are always different compounds with different properties, but with the same formula. 

Constitutional isomers are compounds with different carbon skeletons, different functional groups, and different functional group locations. These isomers have different sequential arrangements of atoms. Now let us consider a different type of isomerism. Compounds that have the same sequential arrangement of atoms, but different spatial arrangements, are stereoisomers. This type of isomerism is stereoisomerism. Stereoisomers can exit in several ways in various classes of compounds. For example, cycloalkanes can exist as stereoisomers called geometric isomers. 

Alkanes are a class of saturated hydrocarbons with the general formula C H2n. -2- They contain no functional groups, are relatively inert, and can be either straight-chain (normal) or branched. Alkanes are named by a series of IUPAC rules of nomenclature. Compounds that have the same chemical formula but different structures are called isomers. More specifically, compounds such as butane and isobutane, which differ in their connections between atoms, are called constitutional isomers. 

Two molecules share an isomeric relationship if they have the same molecular formula. All molecules with the same molecular formula constitute a set of structural isomers and are to some degree similar. However, they may have different chemical constitutions, as indicated in Figure 1.2.1 for 1-butanol and five structural isomers. Any two of these molecules placed in the same row make a pair of constitutional isomers. For the purpose of property estimation, it is helpful to further classify the constitutional isomers according to type and position of the functional groups and branching of the isomers. In the dicussion that follows, we focus on two different types of isomeric sets positional isomers and branched isomers. 

Isomers are compounds with identical molecular formulas but different structural formulas. Structural or constitutional isomers differ in the bonding arrangement of atoms different atoms are attached to one another in the isomers. There are three types of structural isomers. Skeletal isomers differ in their carbon skeletons or chains. In positional isomers, the difference is in the position of a non-carbon group or multiple bond. Functional isomers belong to different groups or classes of organic... 

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