1,3-Benzenedicarboxylic acid, 5,5′-[(1,3,8,10-tetrahydro-1,3,8,10-tetraoxoanthra[2,1,9-def:6,5,10-d'e'f′]diisoquinoline-2,9-diyl)diimino]bis-

1,3-Benzenedicarboxylic acid, 5,5′-[(1,3,8,10-tetrahydro-1,3,8,10-tetraoxoanthra[2,1,9-def:6,5,10-d'e'f′]diisoquinoline-2,9-diyl)diimino]bis-