Chapter 25, Problem 24QP

Interpretation Introduction

Interpretation:

Thegiven molecular models are to be converted into a condensed structural formula, a Kekule structure, and a skeletal (line) structure.

Concept Introduction:

Molecular model of a chemical compound represents the three-dimensional position of the atoms along with the bonds between them. The atoms are represented by spheres, connected by rods, which represent the bonds.

Wedges represent the bonds toward the viewer, dashes represent the bonds away from the viewer, and solid lines represent the bonds in the plane of the image.

The structural formula of a chemical compound consists of the graphic representation of the molecular structure and the arrangement of atoms.

In an organic molecule, the structure representation of atoms takes place by single or double bonds without lone pairs; it is called theKekule structure.

In an organic molecule, bonds are not represented by single lines or branched chains; it is called the condensed structural formula.

In an organic molecule, when the structure consists of straight lines that represent $\text{C}-\text{C }$ bonds in which carbon and hydrogen atoms are not shown, it is called skeletal structures.

Answer to Problem 24QP

Solution: The structures of the compounds are represented below.

(a)

Condensed:

Kekule:

Skeletal (line):

(b)

Condensed:

Kekule:

Skeletal (line)

(c)

Condensed

Kekule

Skeletal (line):

Explanation of Solution

a) ${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{: Dihydroxyacetone,}$ an intermediate is glycolysis, the process by which glucose is converted to energy

In the condensed structural formula, the compound consists of two functional groups, that is, $\text{CO}$ andtwo $\text{OH}$ groups are attached to the carbon atoms.

In thestructure given below, there are three carbon atoms, in which two carbon atoms are linked to the $\text{O}$ atom with single bonding, one carbon atom is bonded with the oxygen atom with double bonds, and the required hydrogens are bonded with carbon atoms. This representation takes place by the Kekule structure.

The skeletal structure consists of a line representation of the bond between atoms. In this structure, carbon and hydrogen atoms are not shown except heteroatoms. Two oxygen atoms are linked by a single line and one oxygen atom is linked by double lines. A single line representsa single bond and double lines represent double bonds.

b) ${\text{C}}_{\text{4}}{\text{H}}_{\text{5}}\text{Cl:}\text{Chloroprene}$ that gives neoprene on polymerization

The condensed structural formula consists of two functional groups that are $\text{Cl}$ and two $\text{C=C}$. There are two ${\text{CH}}_2$ and one $\text{CH}$ group present in this compound. Both functional groups are connected to carbon atoms.

.

In the structure given below, there are four carbon atoms in the compounds that are linked by alternate single and double bonds, in which one carbon atom is linked to the $\text{Cl}$ atom with single bonding, and the required hydrogens are bonded with carbon and oxygen atoms. This representation takes place by the Kekule structure.

The skeletal structure consists of the line representation of the bond between atoms. In this structure, carbon and hydrogen atoms are not shown except heteroatoms. A single line represents single bonds and double lines represent double bonds. The $\text{Cl}$ atom is linked by a single line with the carbon atom.

Given information: The molecular model of the compound is represented below:

c) ${\text{C}}_{\text{6}}{\text{H}}_{\text{13}}{\text{NO}}_{\text{2}}\text{:}\text{Isoleucine,}$ one of the 20 amino acids that occur in proteins

In thecompound given below, there are two ${\text{CH}}_{\text{3}}$ groups, one ${\text{CH}}_2$ group, and two $\text{CH}$ groupsbonded with carbon atoms by single bonding. The structural formula also consists of two functional groups that are the $\text{COOH}$ and the ${\text{NH}}_2$ groups.

In the structure given below, there are sixcarbon atoms including the $\text{COOH}$ functional groupin which five carbon atoms are linked by single bonds, one carbon atom is attached to the oxygen atom by a double bond, the ${\text{NH}}_2$ group is bonded to the carbon atom with a single bond, and the required hydrogen atoms are bonded in the compound. This representation takes place by the Kekule structure

The skeletal structure contains the line representation to show the bond between atoms. In this structure, carbon and hydrogen atoms are not shown except heteroatoms. Oxygen atoms are linked to the carbon atom with single and double lines, and the ${\text{NH}}_2$ group is linked to the carbon atom by a single line. A single line represents a single bond and double lines represent double bonds.