Azo compounds for type I phototherapy

A compound of formula

• wherein Q is a single bond or —CR1R2;
• R1 and R2 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, C1-C10 alkoxyalkyl, C1-C10 polyhydroxyalkyl, —(CH2)aCO2H, and —(CH2)bNR3R4;
• R3 and R4 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, C1-C10 polyhydroxyalkyl, and —(CH2)aCO2H;
• R5, R6, and R7 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, hydroxyl, —SO3H, C1-C10 alkoxyl, C1-C10 polyhydroxyalkyl, C1-C10 polyalkoxyalkyl, —(CH2)aCO2H, and —(CH2)bNR3R4;
• X is selected from the group consisting of —CR8R9, —O—, —NR3, —S—, and —C═O;
• Y is selected from the group consisting of —CR10R11, —O—, —NR3, —S—, and —C═O;
• Z is selected from the group consisting of —CR12R13, —O—, —NR3, —S—, and —C═O;
• R8 to R13 are independently selected from the group consisting of hydrogen, C1-C10 alkyl, C5-C10 aryl, C1-C10 alkoxyalkyl, C1-C10 polyhydroxyalkyl, —(CH2)aCO2H, and —(CH2)bNR3R4;
• R5-R6, R6-R7, R8-R10, or R10-R12 together optionally form a six-membered ring;
• E is either a hydrogen atom or is selected from the group comprising antibodies, peptides, peptidomimetics, carbohydrates, glycomimetics, drugs, hormones, or nucleic acids;
• L is the linker unit —(CH2)c—, a and b independently range from 0 to 10, and c ranges from 1 to 10.