View source for Methyl violet

{{Chembox new
|   Name = '''Methyl violet 2B'''
|   ImageFile = Methyl Violet 2B.png
|   ImageSize = 200px
|   ImageName = Methyl violet
|   IUPACName = Methyl violet 2B
| Section1 = {{Chembox Identifiers
|   CASNo = 8004-87-3
|   SMILES = [Cl-].CN(C)c1ccc(cc1)C(=C2C=CC(=[NH2+])<br />C=C2)c3ccc(cc3)N(C)C
  }}
| Section2 = {{Chembox Properties
|   Formula = C<sub>24</sub>H<sub>28</sub>N<sub>3</sub>Cl
|   MolarMass = 393.958 g/mol (6B)
|   Density =
|   MeltingPt = 137 °C (279 °F)
|   BoilingPt = }}
}}
{{SI}}


'''Methyl violet''' is the name given to a group of similar [[chemical]]s used as [[pH indicator]]s and [[dye]]s. Methyl violets are mixtures of tetramethyl, pentamethyl and hexamethyl [[pararosanilin]]s. By blending the different versions, the dyemaker can create different shades of violet in the final dye. The more methylated the compound (the more [[methyl]] groups attached), the deeper blue the final color will be:
*Tetramethyl (four [[methyl]]s) is known as methyl violet 2B, and this specific chemical finds uses in [[chemistry]] and [[medicine]].
*Pentamethyl (five [[methyl]]s) is known as methyl violet 6B, and is darker (in dye form) than 2B.
*Hexamethyl (six [[methyl]]s) is known as methyl violet 10B, or specifically as '''crystal violet'''. This is much darker than 2B, and often darker than 6B.

In pure form, the tetramethyl appears as [[Lustre (mineralogy)|lustrous]] blue-green [[crystal]]s that melt at 137°[[Celsius|C]] (279°[[Fahrenheit|F]]).

The main use of methyl violet (by sheer volume used worldwide) is to dye textiles purple and give deep violet colors in paints and printing ink.

Methyl violet 2B (simply called ''methyl violet'') is used in [[chemistry]] as a [[pH indicator]] to test [[pH]] ranges from 0 to 1.6. At the [[acid]] end of its measuring range, it takes on a yellow color. At the [[alkaline]] end, it becomes bluish-violet. Methyl violet can be supplied as premade pH testing paper, or it can be supplied as pure crystals and dissolved in the sample being checked.

{{pH_indicator_template|indicator_name=Methyl violet 2B |low_pH=0.0 |high_pH=1.6 |low_pH_color=yellow |high_pH_color=violet}}

In medicine, Methyl Violet 10B is known as [[Gentian violet]] and is the active ingredient in [[Gram's stain]], used to classify bacteria. Gentian violet destroys cells, and is used as a moderate-strength external [[disinfectant]]. Gentian violet is very poisonous to most animals, dogs and cats included &mdash; it should never be used as a disinfectant for animals' skin.

Methyl violet has also the ability of binding [[DNA]]. Therefore, in biomedical sciences, it is used for cell viability assays. The binding to DNA can also cause disruption in DNA replication process, which can lead to [[mutation]]s and [[cancers]].

Methyl violets are soluble in [[water]], [[ethanol]], [[diethylene glycol]], and dipropylene glycol. Specifically, methyl violet 6B is 2.93% soluble in water and 15.21% soluble in ethanol.

Methyl violet should not be confused with [[methyl blue]] or [[methylene blue]], two other stains.

<gallery>
Image:Methyl Violet 2B.png|Methyl Violet 2B
Image:Methyl Violet 6B.png|Methyl Violet 6B
Image:Methyl Violet 10B.png|Methyl Violet 10B
</gallery>

==References==
*[http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-KV-d.htm Kristallviolett – ein pH-Indikator] (in German)
<references/>
{{Stains}}
[[Category:Triarylmethane dyes]]
[[Category:Disinfectants]]
[[Category:pH indicators]]
[[Category:Staining dyes]]



[[cs:Methylová violeť]]
[[de:Kristallviolett]]
[[fr:Violet de gentiane]]
[[pl:Fiolet krystaliczny]]
[[pt:Violeta de metila]]
[[ro:Metil violet]]
[[ru:Метиловый фиолетовый]]
[[sl:Metilvijolično]]
[[fi:Metyylivioletti]]
[[tr:Metil menekşesi (metil viyole)]]
[[zh:甲基紫]]

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