A method for dyeing keratin fibers, comprising applying to said keratin fibers a composition comprising at least one compound selected from compounds of formula (I) or (II) below, organic or mineral acid or base salts thereof, tautomers thereof, optical isomers thereof, geometrical isomers thereof, or solvates thereof:
- wherein formulae (I) and (II):
- n represents an integer equal to 0, 1, 2, 3, 4 or 5;
- R1 represents:
- a halogen atom,
- a sulfonic radical —SO3H or sulfonate radical —SO3−, M+;
- a carboxyl radical —CO2H, a carboxylate radical —COO−;
- an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more identical or different radicals chosen from C1-C4 alkyl and C1-C4 hydroxyalkyl;
- an aromatic or non-aromatic, 5- to 6-membered non-cationic heterocycle, substituted with:
- an ammonium radical —N+RR′R″ with R, R′ and R″, which may be identical or different, representing a (C1-C4)alkyl group optionally substituted with one or more hydroxyl groups, or
- an aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, which is optionally substituted with one or more identical or different radicals chosen from C1-C4 alkyl and C1-C4 hydroxyalkyl,
- an ammonium radical —N+RR′R″, wherein R, R′ and R″, which may be identical or different, represent a C1-C4 alkyl group, or
- a radical —W—R7, wherein:
- W represents:
- an oxygen or sulfur atom,
- a divalent group —N(R8)— or
- a linear or branched, saturated or unsaturated, divalent hydrocarbon-based chain, comprising from 1 to 14 carbon atoms, said hydrocarbon-based chain being:
- optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals:
- i) hydroxyl, ii) (di)(C1-C6)(alkyl)amino, iii) ammoniums —N+RR′R″, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals:
- a) ammonium —N+RR′R″, and b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C1-C4 alkyl;
- and/or
- optionally interrupted, optionally starting, and/or optionally terminating with one or more divalent heteroatoms or groups, which may be identical or different, chosen from:
- —O—, —S—, —N(R10)—, —S(O)—, —S(O)2—, and —C(X)— with X representing an oxygen or sulfur atom or a group NR10 and R10 representing a hydrogen atom or a (C1-C6)alkyl group, and
- combinations thereof;
- R7 and R8, which may be identical or different, represent:
- a hydrogen atom,
- a linear or branched C1-C14 alkyl group, said alkyl group being:
- optionally interrupted with one or more heteroatoms or groups selected from —O—, —S—, —N(R10)—, —S(O)—, —S(O)2—, —C(X)—, or combinations thereof;
- or
- optionally substituted with one or more radicals, which may be identical or different, chosen from the following radicals:
- i) hydroxyl, ii) (di)(C1-C6)(alkyl)amino, iii) ammoniums —N+RR′R″, iv) aromatic or non-aromatic, optionally substituted, 5- to 10-membered cationic heterocycles, v) aromatic or non-aromatic, 5- or 6-membered non-cationic heterocycles, substituted with one or more radicals, which may be identical or different, chosen from the following radicals:
- a) ammonium —N+RR′R″, or b), aromatic or non-aromatic, 5- to 10-membered cationic heterocycle, optionally substituted with one or more identical or different radicals chosen from C1-C4 alkyl;
- R3 and R4, which may be identical or different, representing a hydrogen atom;
- R5 and R6, which may be identical or different, represent an atom or group chosen from:
- a hydrogen atom,
- a halogen atom,
- a C1-C6 alkyl radical,
- a (C1-C6)alkyl radical substituted with one or more radicals chosen from the following radicals:
- i) hydroxyl, ii) amino —NH2, iii) (C1-C6)alkylamino, and iv) di(C1-C6)alkylamino,
- a (C1-C6)alkoxy radical, or
- a (C1-C6)alkoxy radical substituted with one or more radicals chosen from the following radicals:
- i) hydroxyl, ii) amino, iii) (C1-C6)alkylamino, and iv) di(C1-C6)alkylamino,
- wherein:
- the compounds of formulae (I) and (II) are symmetric,
- when the compound of formula (I) or (II) is cationic, it optionally comprises one or more anions An− and optionally one or more cations M+ to ensure the electrical neutrality of the molecule;
- wherein:
- An− denoting an anion chosen from bromide, chloride, a methylsulfate ion, a toluenesulfonate ion, or a mixture thereof;
- M+ representing a cation chosen from sodium, potassium, magnesium, calcium, or ammonium.