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Reichardt's dye (Betaine 30) is an organic 
This chemical is named for , who developed it when working as a doctoral student in the lab of . It is thus also sometimes called Dimroth–Reichardt dye. The names also sometimes refer to some close chemical analogs, in particular, the one having para substituted ''tert''-butyl groups on the phenyl rings.
dye
Juan de Guillebon, better known by his stage name DyE, is a French musician. He is known for the music video of the single "Fantasy
Fantasy is a genre of speculative fiction that involves supernatural or Magic (supernatural), magical ele ...
belonging to the class of azo merocyanine betaine
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a Quaternary ammonium cation, quaternary ammonium or phosphonium cation (generally: Onium compou ...
s. This dye is notable for its solvatochromic properties, meaning it changes color depending on the solvent
A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...
in which it is dissolved. It has one of the largest solvatochromic effects ever observed, with color varying across the entire visible spectrum
The visible spectrum is the spectral band, band of the electromagnetic spectrum that is visual perception, visible to the human eye. Electromagnetic radiation in this range of wavelengths is called ''visible light'' (or simply light).
The optica ...
. As a result, it gives striking visual results for chemical demonstrations.
This chemical is named for , who developed it when working as a doctoral student in the lab of . It is thus also sometimes called Dimroth–Reichardt dye. The names also sometimes refer to some close chemical analogs, in particular, the one having para substituted ''tert''-butyl groups on the phenyl rings.
Synthesis
A newer synthesis is: 2,6-Diphenylphenol is nitrated with dilutednitric acid
Nitric acid is an inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but samples tend to acquire a yellow cast over time due to decomposition into nitrogen oxide, oxides of nitrogen. Most com ...
to 4-nitro-2,6-diphenylphenol and subsequently reduced with sodium dithionite to the amine
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...
. This is reacted in presence of sodium acetate
Sodium acetate, CH3COONa, also abbreviated Sodium, NaOxygen, OAcetyl, Ac, is the sodium Salt (chemistry), salt of acetic acid. This salt is colorless, deliquescent, and hygroscopy, hygroscopic.
Applications
Biotechnological
Sodium acetate is u ...
in ethanol
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...
with 2,4,6-triphenylpyryliumhydrogensulfate to the hydrogen sulfate of the dye and the betaine
A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a Quaternary ammonium cation, quaternary ammonium or phosphonium cation (generally: Onium compou ...
is formed by adding sodium hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions .
Sodium hydroxide is a highly corrosive base (chemistry), ...
.
References
{{reflist Fluorescent dyes Pyridinium compounds Phenolates