| abstract |
The invention concerns symmetric diazo cationic compounds of formula (I), their resonance forms, as well as their acid-addition salts and their solvates, wherein W1, identical represent a hydrogen atom, a halogen atom, a -NR5R6, OR7, -NR4-Ph-NR5R6, -NR4-Ph-OR7, -O-Ph-OR7, -O-Ph-NR5R6 group; L represents a cationic of non-cationic linker arm. The invention also concerns dyeing compositions comprising in a suitable medium for dyeing keratinous fibers, such compounds as direct dyeing agent, as well as a method for dyeing keratinous fibers using said composition and a multiple-compartment device. |