Constitutional isomers kinds

Compounds like the two C4M [() molecules and the three C3I I 12 molecules, which have the same formula but different structures, are called isomers, from the Greek isos + meros, meaning "made of the same parts." Isomers are compounds that have the same numbers and kinds of atoms but differ in the way the atoms are arranged. Compounds like butane and isobutane, whose atoms are connected differently, are called constitutional isomers. We ll see shortly that other kinds of isomers are also possible, even among compounds whose atoms are connected in the same order. As Table 3.2 shows, the number of possible alkane isomers increases dramatically as the number of carbon atoms increases. 

R Constitutional isomers (Section 3.2) are compounds whose atoms are connected differently. Among the kinds of constitutional isomers we ve seen are skeletal, functional, and positional isomers. 

The tetramerization of suitable monopyrroles is one of the simplest and most effective approaches to prepare porphyrins (see Section 1.1.1.1.). This approach, which is best carried out with a-(hydroxymethyl)- or ot-(aminomethyl)pyrroles, can be designated as a biomimetic synthesis because nature also uses the x-(aminomethyl)pyrrole porphobilinogen to produce uroporphyrinogen III. the key intermediate in the biosynthesis of all kinds of naturally occurring porphyrins, hydroporphyrins and corrins. The only restriction of this tetramerization method is the fact that tnonopyrroles with different -substituents form a mixture of four constitutionally isomeric porphyrins named as porphyrins I, II, III, and IV. In the porphyrin biosynthesis starting from porphobilinogen, which has an acetic acid and a propionic acid side chain in the y6-positions, this tetramerization is enzymatically controlled so that only the type III constitutional isomer is formed. 

Transition metal complexes in particular show several kinds of constitution isomers,... 

Site-selectivity a Formation of constitutional isomers via the same kind of reaction... 

Selective formation and elimination of sulphonamides permit synthesis of constitutional isomers ( dendro isomers ) of dendritic architectures of the kind shown in Fig. 2.20. 

Draw the four constitutional isomers having molecular formula C4HQBr and indicafe how many different kinds of carbon atoms each has. 

Constitutional isomers Compounds that contain the same numbers of the same kinds of atoms but that differ in the order in which their atoms are bonded together. Also known as structural isomers. 

As the number and kinds of atoms increase, the number of constitutional isomers—that is, the number of structural formulas that can be written for a given molecular formula—also increases C2H6O has the two that you ve seen, C3HgO has three, and C4H10O, seven. (We ll discuss this and other types of isomerism fully later in the text.)... 

The constitution of a molecule (number of, kind of, and connectivities of atoms) may be represented by a two-dimensional map in which the interatomic linkages (bonds) are drawn as fines. There are two constitutional isomers that are represented by the molecular formula C2HgO ethanol and dimethyl ether. The differences in connectivities, which are not evident in the common constitutional inventory C2H6O, can be conveyed by typographical fine formulas (CH3CH2OH for etfianol and CH3OCH3 for dimethyl ether), or by structural representations (see Figure 2). As the number and kinds of atoms in substances increase, the number of constitutional isomers increases. 

Unlike the atoms in constitutional isomers, the atoms in stereoisomers are connected in the same way. Stereoisomers (also called configurational isomers) differ in the way their atoms are arranged in space. Stereoisomers are different compounds that do not readily interconvert. Therefore, they can be separated. There are two kinds of stereoisomers cis-trans isomers and isomers that contain chirality (ky-RAL-i-tee) centers. 

The second major category of isomers and the focus of this chapter are stereoisomers. Being isomers they too have the same number and kind of building block atoms, but, unlike constitutional isomers, they have identical topologies. Stereoisomers, in turn, are divided into two groups enantiomers and diastereomers. Enantiomers are isomers that are not superimposable on their mirror images. And, by definition, diastereomers are all other stereoisomers that are not enantiomers. 

Ans. Alkenes and cycloalkanes have the same general formula and are constitutional isomers of each other. Knowing that the molecular formula of some unknown such as C5H10 fits the general formula C H2 tells us that it is not an alkane and that it is either an alkene or a cycloalkane. The molecular formula alone does not allow us to distinguish an alkene from a cycloalkane. However, alkenes and cycloalkanes have very different chemical properties. Cycloalkanes have similar chemical behavior as alkanes since both have the same kinds of bonds (C — C and C — H single bonds). The chemistry of alkenes is very different due to the presence of the carbon-carbon double bond (Sec. 12.6). 

We will learn about several kinds of isomers during the course of our study. For now, let us consider a type called constitutional isomers. 

Constitutional isomers are compounds that have the same molecular formula, but different structural formulas. By different structural formulas, we mean that these compounds differ in the kinds of bonds they have (single, double, or triple) or in their cormectivity (the order of attachment among their atoms). 

Isomers are molecules with the same number and kinds ot atoms but ditferent arrangements ot the atoms. Structural (or constitutional) isomers have the same molecular formula but ditferent structural formulas. 

In one kind of constitutional isomer, known as positional isomer, the compounds have... 

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