Symmetrical diazo compounds comprising 2-imidazolium groups and a non-cationic linke, compositions comprising them, method of coloring, and device

摘要

The present disclosure relates to symmetrical cationic diazo compounds of formula (I) below, their resonance forms, and also their acid addition salts and their solvates:; wherein W₁ radicals, which are identical, are chosen from a halogen atom, or an —NR₄-Ph-NR₅R₆, —NR₄-Ph-OR₇, —O-Ph-OR₇ or —O-Ph-NR₅R₆ group or else an —NR₅R₆ or —OR₇ group with certain provisos;L, a non-cationic linker connecting the two identical azo chromophores, is chosen from a covalent bond; an optionally substituted C₁-C₄₀ alkyl radical optionally interrupted by a (hetero)cycle, the alkyl radical being optionally interrupted by at least one heteroatom or group comprising at least one heteroatom or an optionally substituted phenyl radical.;The disclosure further relates to dyeing compositions comprising such compounds as a direct dye in a medium appropriate for the dyeing of keratin fibers, and also to a method of coloring keratin fibers that employs this composition, and a device comprising a plurality of compartments.