a hydrogen atom, a halogen atom or an SO3(M2) group, where M2 is an alkali metal or NH4; M3 is Cr, Ni or Co; and X1+ is an alkali metal cation or NH4 +, or by the structural formula (II): wherein R7 and R8 are each independently a hydrogen atom, a halogen atom such as fluorine, chlorine and bromine, a nitro group, a linear or branched alkyl group having 1 to 5 carbon atoms, a CF3 group or an SO3(