[.mu.-[[7,7'-[[6-[(2-Hydroxyethyl)amino]-1,3,5-triazine-2,4-diyl]diimino]bis[4-hydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]-2-naphthalenesulfonato]](8-)]]dicuprate(4-), tetrasodium

Cuprate(4-), .mu.-7,7-6-(2-hydroxyethyl)amino-1,3,5-triazine-2,4-diyldiiminobis4-(hydroxy-.kappa.O)-3-2-(hydroxy-.kappa.O)-5-sulfophenylazo-.kappa.N1-2-naphthalenesulfonato(8-)di-, tetrasodium