Topic

Supramolecular 1O2 Storage Systems based on Pyridone-Subphthalocyanine-Dyads

Singlet Oxygen (1O2 ), a reactive oxygen species, has a cytotoxic effect on living cells and can be used against bacteria, viruses and in photodynamic therapy. Instead of generating 1O2 in situ at the intended site of action by the interaction of light, oxygen and an appropriate photosensitizer, the delayed provision of reactive oxygen through the thermal decomposition of an endoperoxide (EPO) has recently received broad attention.1 In that context, self-sensitized EPO-forming dyads, in which EPO-forming units are covalently attached to photosensitizers, have become increasingly important.1-4 I am currently investigating the combination of pyridones as EPO-forming units and subphthalocyanines (SubPc) as photosensitizers.

Fig.1 Covalently attached pyridone-SubPc-dyads in axially (left) and peripheral (right) positions.

MATSUMOTO et al. recognized in 2005 the reversible binding of 1O2 by pyridones, which are particularly suitable for biological applications due to their solubility parameters in aqueous media.5The high 1O2-quantum yield of subphthalocyanines and their cone-shaped topology, which minimizes aggregation, make them particularly interesting for these dyads.6

The focus of my work is the synthesis of covalently and supramolecularly attached pyridone-SubPc-dyads, the generation of 1O2 by the irradiation of the photosensitizer (SubPc), the self-sensitized EPO formation by cycloaddition of 1O2 to pyridones and the delayed and controlled release of reactive oxygen via a thermal cycloreversion process.

Fig.2 Generation, storage and release of singlet oxygen by a pyridone-SubPc-dyad.

References

[1] M.A. Filatov, M.O. Senge, Mol. Syst. Des. Eng., 2016, 1, 258-272.
[2] D. Rihter, M.E. Kenney, W.E. Ford, M.A. J. Rodgers, J. Am. Chem. Soc., 1993, 115, 8146-8152.
[3] W. Freyer, H. Stiel, M. Hild, K. Teuchner, D. Leupold, Photochem. Photobiol., 1997, 66, 696-604.
[4] S. Callaghan, M. A. Filatov, E. Sitte, H. Savoie, R. W. Boyle, K. J. Flanagan, M. O. Senge, 
     Photochem, Photobiol. Sci., 2017, 16, 1371-1374.
[5] M. Matsumoto, M. Yamada, N. Watanabe, Chem. Commun., 2005, 4, 483-485.
[6] C. Claessens, D. González-Rodriguez, T. Torres, Chem. Rev., 2002, 102, 835-853.

Presentations

L. Vogt, R. Faust
“Subphthalocyanine-Anthracene-Dyad as a Singlet Oxygen Storage System”, GDCh Wissenschaftsforum (WiFo-2019), Aachen, September 16-18, 2019.

Poster Presentations

L. Vogt, R. Faust
“Subphthalocyanine-Anthracene-Dyad as a Singlet Oxygen Storage System”, Flashtalk, CINSaT autumn colloquium, Kassel, October 16, 2019.

 L. Vogt, R. Faust
“Subphthalocyanine-Anthracene-Dyad as a Singlet Oxygen Storage System”, GDCh Wissenschaftsforum (WiFo-2019), Aachen, September 16-18, 2019. 

 L. Höfer, R. Münnich, R. Faust
“Axially modified Subporphyrazines as Singlet Oxygen Storage Systems”, 10th International Conference on Porphyrins and Phthalocyanines (ICPP-10), München, July 1-6, 2018.

Thesis

L. Höfer
“Axial funktionalisierte Subporphyrazine als Singulett-Sauerstoff-Transporter”, Wissenschaftliche Hausarbeit zum 1. Staatsexamen, Universität Kassel, 2018.