The invention relates to primary para-phenylenediamine compounds substituted with an aliphatic chain comprising a cationic heterocyclic group according to formula (I), as well as the organic or mineral acid or base addition salts thereof, optical isomers, geometric isomers, tautomers, mesomers and/or solvates thereof, such as hydrates. Formula (I), wherein: ALK is a linear or branched, optionally substituted, alkylene chain comprising 3 to 8 carbon atoms; HET+ is a saturated or unsaturated, aromatic or non-aromatic cationic heterocyclic group, optionally substituted, comprising 5 to 0 links, optionally substituted, and comprising one or more ammonium groups; and An−, present or absent, is a mineral or organic anionic counterion ensuring the electroneutrality of the molecule. The present invention also relates to a composition comprising one or more of these previously defined compounds, in a medium suitable for dyeing. The present invention lastly relates to a dyeing device consisting of a first compartment which contains said composition, and a second compartment containing one or more oxidising agents.