Chrysoine resorcinol is a synthetic
azo dye
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C−N=N−C l ...
which was formerly used as a
food additive
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...
. In Europe, it was banned as a food additive in 1977. In the US, it was banned in 1988.
Chrysoine resorcinol can be used as a
pH indicator
A pH indicator is a halochromism, halochromic chemical compound added in small amounts to a Solution (chemistry), solution so the pH (acidity or Base (chemistry), basicity) of the solution can be determined visually or spectroscopically by chang ...
with a color change between pH 11 and pH 12.7.
In
colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception".
It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color p ...
, it has an
absorption maximum of 387
nm.
Preparation
Acid orange 6 can be synthesised via the
azo coupling
In organic chemistry, an azo coupling is an organic reaction, reaction between a diazonium compound () and another aromatic compound that produces an azo compound (). In this electrophilic aromatic substitution reaction, the aryldiazonium cation ...
of
sulfanilic acid
Sulfanilic acid (4-aminobenzenesulfonic acid) is an organic compound with the formula H3NC6H4SO3. It is an off-white solid. It is a zwitterion, which explains its high melting point. It is a common building block in organic chemistry."Sulphanili ...
and
resorcinol
Resorcinol (or resorcin) is a phenolic compound. It is an organic compound with the formula C6H4(OH)2. It is one of three isomeric benzenediols, the 1,3-isomer (or ''meta- (chemistry), meta''-isomer). Resorcinol crystallizes from benzene as co ...
,
Notes
External links
Data at inchem.org
Food colorings
Azo dyes
Benzenesulfonates
Organic sodium salts
Resorcinols
Anilines
Acid dyes
{{OrganicAcid-stub