Malachite green

Malachite green

Names
IUPAC name 4-{[4-(dimethylamino)phenyl](phenyl)methylidene}-N,N-dimethylcyclohexa-2,5-dien-1-iminium chloride
Other names Aniline green; Basic green 4; Diamond green B; Victoria green B
Identifiers
CAS Number	569-64-2 Y
3D model (Jmol)	Interactive image
ChEMBL	ChEMBL186357 Y
ChemSpider	10820 Y
ECHA InfoCard	100.008.476
PubChem	11294
UNII	12058M7ORO Y
InChI InChI=1S/C23H25N2.ClH/c1-24(2)21-14-10-19(11-15-21)23(18-8-6-5-7-9-18)20-12-16-22(17-13-20)25(3)4;/h5-17H,1-4H3;1H/q+1;/p-1 Y Key: FDZZZRQASAIRJF-UHFFFAOYSA-M Y InChI=1/C23H25N2.ClH/c1-24(2)21-14-10-19(11-15-21)23(18-8-6-5-7-9-18)20-12-16-22(17-13-20)25(3)4;/h5-17H,1-4H3;1H/q+1;/p-1 Key: FDZZZRQASAIRJF-REWHXWOFAA
SMILES CN(C)c1ccc(cc1)C(=C2C=CC(=[N+](C)C)C=C2)c3ccccc3.[Cl-]
Properties
Chemical formula	C23H25ClN2 (chloride)
Molar mass	364.911 g/mol (chloride)
Pharmacology
ATCvet code	QP53AX16 (WHO)
Hazards
Main hazards	Moderately toxic, Extreme irritant
EU classification (DSD)	T Xi
Lethal dose or concentration (LD, LC):
LD50 (median dose)	80mg/kg (oral, mouse)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Malachite green is an organic compound that is used as a dyestuff and controversially as an antimicrobial in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Although called malachite green, this dye is not prepared from the mineral malachite - the name just comes from the similarity of color.

Malachite green is classified in the dyestuff industry as a triarylmethane dye and also using in pigment industry. Formally, malachite green refers to the chloride salt [C₆H₅C(C₆H₄N(CH₃)₂)₂]Cl, although the term malachite green is used loosely and often just refers to the colored cation. The oxalate salt is also marketed. The anions have no effect on the color. The intense green color of the cation results from a strong absorption band at 621 nm (extinction coefficient of 10⁵ M⁻¹ cm⁻¹).

Malachite green is prepared by the condensation of benzaldehyde and dimethylaniline to give leuco malachite green (LMG):

Second, this colorless leuco compound, a relative of triphenylmethane, is oxidized to the cation that is MG:

A typical oxidizing agent is manganese dioxide.

Hydrolysis of MG gives an alcohol:

This alcohol is important because it, not MG, traverses cell membranes. Once inside the cell, it is metabolized into LMG. Only the cation MG is deeply colored, whereas the leuco and alcohol derivatives are not. This difference arises because only the cationic form has extended pi-delocalization, which allows the molecule to absorb visible light.