Symbolic Representations of Carbon Networks

Organic molecules often contain extensive networks of carbon atoms. Chemists find it convenient to construct shorthand visual representations of such molecules using a symbolic system of lines that indicate only the position of the bonds (not including bonds to hydrogen atoms), rather than writing out a structure in which the C and H atoms are shown explicitly. To indicate the presence of a carbon atom, a "kink" is shown in the chain's representation. For example, ;the molecule n-butane can be represented as (a) or (b) below:

Cl I,—CH2—CH2—CH3 (a) (b)

The hydrogen atoms are not shown at all in the "stripped-down" version; the number of them at any carbon atom can be deduced by subtracting from 4 the number of bonds to that carbon that are displayed explicitly. Thus in the representation below for 2-chloropropane, carbons #1 and #3 must possess 3 hydrogens, since they are shown as forming one other bond, whereas carbon #2 has one hydrogen, since it is shown as forming three other bonds:

2-chloropropane

2-chloropropane

PROBLEM 4

Write out the full structural formulas for each of the following molecules:

PROBLEM 5

Draw symbolic ("kinky") bond diagrams for each of the following molecules:

(a) CH3—CH2—CH—CH, (b) CH,(CH2)4C

Continue reading here: Common Functional Groups

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