282
ORGANIC COMPOUNDS AND POLYMERS
to display their chemical bonds indicated by horizontal (-) and vertical (1 ) dashes.
The compound methane, CH,, which has a structural formula that may be written in
one of two ways
H
I
€1
H-C-H
or
HCH
(11.2)
I
H
H
is one of the simplest organic compounds, and it is a gas at room temperature.
Figure 1 1.1 shows structural formulas of some examples of other hydrocarbons. The
linear pentane molecule C5H1, has all single bonds, and the 71-conjugated compound
butadiene C,H6 has alternating single and double bonds. The simplest aromatic
compound, or 71-conjugated ring compound, that is, one with alternating single and
double bonds, is benzene C6H,, and the figure shows two ways to represent it. It can
also be expressed in the form H4, where the phenyl group 4 is a benzene ring that is
missing a hydrogen atom, corresponding to -C6H5, where the dash (-) denotes an
incomplete chemical bond. Naphthalene (C,,H,) is the simplest condensed ring
(fused ring) aromatic compound. The bottom panel of Fig. 1 1.1 shows the triplebonded compounds acetylene and diacetylene. Aromatic compounds can contain
other atoms besides carbon and hydrogen, such as chlorine (Cl), nitrogen (N),
oxygen (0), and sulphur (S), as well as atomic groups or radicals such as amino
(-NH,) nitro (-NO,), and the acid group -COOH.
H H H H H
H H H H H
Linear hydrocarbon (pentane)
H H H H
c=c-c=c
H
H
HC-C-C-C-CH
H
7c - conjugated butadiene
H
Benzene
Naphthalene
Aromatic Compounds
HCECH HCEC-CECH
Acetylene
Diacetylene
Figure 11.1. Examples of organic molecules. Acetylene and diacetylene serve as monomers for
the formation of polymers.
ORGANIC COMPOUNDS AND POLYMERS
to display their chemical bonds indicated by horizontal (-) and vertical (1 ) dashes.
The compound methane, CH,, which has a structural formula that may be written in
one of two ways
H
I
€1
H-C-H
or
HCH
(11.2)
I
H
H
is one of the simplest organic compounds, and it is a gas at room temperature.
Figure 1 1.1 shows structural formulas of some examples of other hydrocarbons. The
linear pentane molecule C5H1, has all single bonds, and the 71-conjugated compound
butadiene C,H6 has alternating single and double bonds. The simplest aromatic
compound, or 71-conjugated ring compound, that is, one with alternating single and
double bonds, is benzene C6H,, and the figure shows two ways to represent it. It can
also be expressed in the form H4, where the phenyl group 4 is a benzene ring that is
missing a hydrogen atom, corresponding to -C6H5, where the dash (-) denotes an
incomplete chemical bond. Naphthalene (C,,H,) is the simplest condensed ring
(fused ring) aromatic compound. The bottom panel of Fig. 1 1.1 shows the triplebonded compounds acetylene and diacetylene. Aromatic compounds can contain
other atoms besides carbon and hydrogen, such as chlorine (Cl), nitrogen (N),
oxygen (0), and sulphur (S), as well as atomic groups or radicals such as amino
(-NH,) nitro (-NO,), and the acid group -COOH.
H H H H H
H H H H H
Linear hydrocarbon (pentane)
H H H H
c=c-c=c
H
H
HC-C-C-C-CH
H
7c - conjugated butadiene
H
Benzene
Naphthalene
Aromatic Compounds
HCECH HCEC-CECH
Acetylene
Diacetylene
Figure 11.1. Examples of organic molecules. Acetylene and diacetylene serve as monomers for
the formation of polymers.