- German chemist
who studied the extraction and exploitation of coal-tar derivatives,
mainly for dyes.
In 1881 he devised a process for the production of pure primary amines
from amides.
Hofmann was born and educated in Giessen, Hesse. He was professor at
the Royal College of Chemistry in London 1845-65 and at Berlin from
1865.
In 1858, Hofmann obtained the dye known as fuchsine or magenta by the
reaction of carbon tetrachloride (tetrachloromethane) with aniline (phenylamine).
Later he isolated from it a compound which he called rosaniline and
used this as a starting point for other aniline dyes, including aniline
blue (triphenyl rosaniline). With alkyl iodides (iodoalkanes) he obtained
a series of violet dyes, which he patented 1863. These became known
as 'Hofmann's violets' and were a considerable commercial and financial
success.
The term 'valence' is a contraction of his notion of 'quantivalence'
and he devised much of the terminology of the paraffins (alkanes) and
their derivatives that was accepted at the 1892 Geneva Conference on
nomenclature.
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