Complexes métallifères de composés polyazoïques, leur préparation et leur utilisation comme colorants

The invention provides a 1:2 metal complex in which at least one of the complexants is a polyazo compound of formula (I) wherein -A1-(CO)p-OH signifies the radical of a diazo component of formula H2N-A-(CO)p-OH, in which the substituent -(CO)p-OH is in ortho-position to the diazotizable amino group -NH2, -A- is the ortho-bivalent radical and p signifies 0 or 1, or a modified derivative thereof, -X- signifies an aromatic bivalent radical, -B1 signifies the radical of a coupling component HB, or a modified derivative thereof, m signifies 0 or 1, n signifies 0, 1 or 2 and M signifies hydrogen or a cation, with the proviso that m+n=1 or 2, or a mixture of such complexes and to the use thereof as dyestuffs, in particular for the dyeing of a substrate dyeable with anionic dyes, especially of leather or pelts.