Compound having the general structure III: where R 1, R 2, R 3, R 4, R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13 are selected from: - H, - (C 1 -C 12)-alkyl, -O- (C 1 -C 12)-alkyl, -O- (C 6 -C 20)-aryl, - (C 6 -C 20)-aryl, -S-alkyl, -S-aryl, halogen, COO- (C 1 -C 12)-alkyl, CONH- (C 1 -C 12)-alkyl, -CO- (C 1 -C 12)-alkyl, -CO- (C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2; where the alkyl and aryl groups mentioned may be substituted as follows: substituted - (C 1 -C 12) -alkyl groups and substituted -(C 1 -C 12)-alkoxy groups may have one or more substituents depending on their chain length; the substituents are mutually independently selected from - (C 3 -C 12) - cycloalkyl, - (C 3 -C 12)-heterocycloalkyl, - (C 6 -C 20)-aryl, fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl, substituted - (C 6 -C 20)-aryl groups and - (C 6 -C 20)-aryl- (C 6 -C 20)-aryl groups may have one or more substituents depending on their ring size; these substituents are mutually independently selected from -H, -(C 1 -C 12)-alkyl, -O-(C 1 -C 12)-alkyl, -O-(C 6 -C 20)-aryl, -(C 6 -C 20)-aryl, -halogen, -COO-(C 1 -C 12)-alkyl, -CONH-(C 1 -C 12)-alkyl, -(C 6 -C 20)-aryl-CON[(C 1 -C 12)-alkyl] 2, -CO-(C 1 -C 12)-alkyl, -CO-(C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H; -SO 3 Na,-NO 2, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2. R 1, R 2, R 3, R 4, R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13 are selected from: - H, - (C 1 -C 12)-alkyl, -O- (C 1 -C 12)-alkyl, -O- (C 6 -C 20)-aryl, - (C 6 -C 20)-aryl, -S-alkyl, -S-aryl, halogen, COO- (C 1 -C 12)-alkyl, CONH- (C 1 -C 12)-alkyl, -CO- (C 1 -C 12)-alkyl, -CO- (C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2; - H, - (C 1 -C 12)-alkyl, -O- (C 1 -C 12)-alkyl, -O- (C 6 -C 20)-aryl, - (C 6 -C 20)-aryl, -S-alkyl, -S-aryl, halogen, COO- (C 1 -C 12)-alkyl, CONH- (C 1 -C 12)-alkyl, -CO- (C 1 -C 12)-alkyl, -CO- (C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2; where the alkyl and aryl groups mentioned may be substituted as follows: substituted - (C 1 -C 12) -alkyl groups and substituted -(C 1 -C 12)-alkoxy groups may have one or more substituents depending on their chain length; the substituents are mutually independently selected from - (C 3 -C 12) - cycloalkyl, - (C 3 -C 12)-heterocycloalkyl, - (C 6 -C 20)-aryl, fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl, substituted - (C 6 -C 20)-aryl groups and - (C 6 -C 20)-aryl- (C 6 -C 20)-aryl groups may have one or more substituents depending on their ring size; these substituents are mutually independently selected from -H, -(C 1 -C 12)-alkyl, -O-(C 1 -C 12)-alkyl, -O-(C 6 -C 20)-aryl, -(C 6 -C 20)-aryl, -halogen, -COO-(C 1 -C 12)-alkyl, -CONH-(C 1 -C 12)-alkyl, -(C 6 -C 20)-aryl-CON[(C 1 -C 12)-alkyl] 2, -CO-(C 1 -C 12)-alkyl, -CO-(C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H; -SO 3 Na,-NO 2, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2. substituted - (C 1 -C 12) -alkyl groups and substituted -(C 1 -C 12)-alkoxy groups may have one or more substituents depending on their chain length; the substituents are mutually independently selected from - (C 3 -C 12) - cycloalkyl, - (C 3 -C 12)-heterocycloalkyl, - (C 6 -C 20)-aryl, fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl, substituted - (C 6 -C 20)-aryl groups and - (C 6 -C 20)-aryl- (C 6 -C 20)-aryl groups may have one or more substituents depending on their ring size; these substituents are mutually independently selected from -H, -(C 1 -C 12)-alkyl, -O-(C 1 -C 12)-alkyl, -O-(C 6 -C 20)-aryl, -(C 6 -C 20)-aryl, -halogen, -COO-(C 1 -C 12)-alkyl, -CONH-(C 1 -C 12)-alkyl, -(C 6 -C 20)-aryl-CON[(C 1 -C 12)-alkyl] 2, -CO-(C 1 -C 12)-alkyl, -CO-(C 6 -C 20)-aryl, -COOH, -OH, -SO 3 H; -SO 3 Na,-NO 2, -CN, -NH 2, -N[(C 1 -C 12)-alkyl] 2.