Monofunctionalized perylenetetracarboxylic acid bismides

A perylenetetracarboxylic acid bisimide of the structural formula (I)

• and wherein R3, R4, R5 or/and R6 comprise aromatic or heteroaromatic radicals,
• wherein R1 and R2 are different organic radicals selected independently from secondary or tertiary aliphatic radicals or, substituted or unsubstituted, mono- or bicyclic, aromatic, or heteroaromatic radicals having 3-30 carbon atoms, one of the radicals having a group for coupling to a binding partner selected from the group consisting of active esters, maleimides, isocyanates, sulfonyl halides, carbonyl halides, iodoacetamides, aziridines, epoxides, acyl azides, acyl nitriles, sulfonic acid groups, and carboxylic acid groups, and at least two of R3, R4, R5 and R6 are each independently aromatic or heteroaromatic radicals which contain at least one uncharged, positively charged, or negatively charged hydrophilic group, and the uncharged hydrophilic groups are selected from hydroxyl groups or polyoxy -C2-C4-alkylene groups, the positively charged hydrophilic groups are selected from amino groups or ammonium groups, and the negatively charged hydrophilic groups are selected from SO3H, COOH, SO3M, or COOM, wherein M is a cation, and at least one of R3, R4, R5 and R6 has the general structural formula (III):
• wherein n is an integer of 1-3.