Phenylene
The phenylene group (C6H4) is based on a di-substituted benzene ring (arylene). For example, poly(p-phenylene) is a polymer built up from para-phenylene repeating units.
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Wikipedia
The phenylene group (C6H4) is based on a di-substituted benzene ring (arylene). For example, poly(p-phenylene) is a polymer built up from para-phenylene repeating units.