CUPRATE(3-),[.MU.-[4-[[3,3'-DI(HYDROXY-.KAPPA.O)-4'-[[2-(HYDROXY-.KAPPA.O)-6-SULFO-1-NAPHTHALENYL]AZO-.KAPPA.N1][1,1'-BIPHENYL]-4-YL]AZO-.KAPPA.N1]-3-(HYDROXY-.KAPPA.O)-2,7-NAPHTHALENEDISULFONATO(7-)]]DI-,TRILITHIUM