Mauveine, also known as aniline purple and Perkin's mauve, was one of the first synthetic
dyes.[1][2] It was discovered
serendipitously by
William Henry Perkin in 1856 while he was attempting to synthesise the phytochemical
quinine for the treatment of
malaria.[3] It is also among the first chemical dyes to have been mass-produced.[4][5]
Mauveine A (C26H23N+4X−) incorporates 2 molecules of
aniline, one of p-toluidine, and one of o-toluidine. Mauveine B (C27H25N+4X−) incorporates one molecule each of aniline, p-toluidine, and two of o-toluidine. In 1879, Perkin showed mauveine B related to
safranines by
oxidative/
reductive loss of the p-tolyl group.[7] In fact,
safranine is a 2,8-dimethyl
phenazinium salt, whereas the
parasafranine produced by Perkin is presumed[8] to be the 1,8- (or 2,9-) dimethyl
isomer.
The molecular structure of mauveine proved difficult to determine, finally being identified in 1994.[9] In 2007, two more were isolated and identified: mauveine B2, an isomer of mauveine B with methyl on different aryl group, and mauveine C, which has one more p-methyl group than mauveine A.[10]
In 2008, additional mauveines and pseudomauveines were discovered, bringing the total number of these compounds up to 12.[11] In 2015 a crystal structure was reported for the first time.[12]
History
Mauveine #8D029B #8D029B
In 1856,
William Henry Perkin, then age 18, was given a challenge by his professor,
August Wilhelm von Hofmann, to synthesize
quinine. In one attempt, Perkin
oxidized aniline using
potassium dichromate, whose
toluidine impurities reacted with the aniline and yielded a black solid, suggesting a "failed" organic synthesis. Cleaning the flask with alcohol, Perkin noticed
purple portions of the solution.
Suitable as a dye of
silk and other
textiles, it was
patented by Perkin, who the next year opened a dyeworks mass-producing it at
Greenford on the banks of the
Grand Union Canal in
Middlesex.[13] It was originally called aniline purple. In 1859, it was named mauve in England via the French name for the
mallow flower, and chemists later called it mauveine.[14] Between 1859 and 1861, mauve became a fashion must have. The weekly journal All the Year Round described women wearing the colour as "all flying countryward, like so many migrating birds of purple paradise".[15]Punch magazine published cartoons poking fun at the huge popularity of the colour “The Mauve Measles are spreading to so serious an extent that it is high time to consider by what means [they] may be checked.”[16][17][18]
By 1870, demand succumbed to newer synthetic colors in the
synthetic dye industry launched by mauveine.
In the early 20th century, the U.S. National Association of Confectioners permitted mauveine as a food coloring with a variety of equivalent names: rosolan, violet paste, chrome violet, anilin violet, anilin purple, Perkin's violet, indisin, phenamin, purpurin and lydin.[19]
^Meth-Cohn, O.; Smith, M. (1994). "What did W. H. Perkin actually make when he oxidised aniline to obtain mauveine?". Journal of the Chemical Society, Perkin Transactions 1. 1994: 5–7.
doi:
10.1039/P19940000005.
^Seixas De Melo, J.; Takato, S.; Sousa, M.; Melo, M. J.; Parola, A. J. (2007). "Revisiting Perkin's dye(s): The spectroscopy and photophysics of two new mauveine compounds (B2 and C)". Chemical Communications (25): 2624–6.
doi:
10.1039/b618926a.
PMID17579759.
^Sousa, Micaela M.; Melo, Maria J.; Parola, A. Jorge; Morris, Peter J. T.; Rzepa, Henry S.; De Melo, J. Sérgio Seixas (2008). "A Study in Mauve: Unveiling Perkin's Dye in Historic Samples". Chemistry - A European Journal. 14 (28): 8507–8513.
doi:
10.1002/chem.200800718.
hdl:10316/8229.
PMID18671308.