1,7-disubstituted perylene-3,4,9,10-tetracarboxylic acids, their dianhydrides and diimides

A 1,7-disubstituted perylene-3,4,9,10-tetracarboxylic diimide of the general formula VI

• where
• X1 is bromine or is —L—R, where
• L is 1,2-ethylene, 1,2-ethenylene or 1,2-ethynylene and
• R is hydrogen or C1-C30-alkyl whose carbon chain can be interrupted by one or more groups —O—, —S—, —NR3—, —CO— and/or —SO2— and/or which can be substituted one or more times by —COOR3, —SO3R3, hydroxyl, cyano, C1-C6-alkoxy, C5-C8-cycloalkyl or aryl or by a 5- to 7-membered heterocyclic radical which is attached via a nitrogen atom and can include further heteroatoms and/or can be aromatic, R3 being hydrogen or C1-C6-alkyl;
• X2 is bromine or —L—R;
• R4 is C4-C30-alkyl whose carbon chain can be interrupted by one or more groups —O—, —S— or —CO—, or is C5-C8-cycloalkyl or aryl which can be substituted one or more times by C1-C6-alkyl or C1-C6-alkoxy.