Ruthenium(II) Complexes with Styryl-Derivatized Bipyridine Ligands for Two Photon Absorption and Photodynamic Therapy
Year: 2026
Type: preprint
Abstract: Cancer remains a major global health challenge, and the limitations of conventional therapies continue to motivate more selective treatment strategies. Photodynamic therapy (PDT) relies on the light-triggered generation of reactive oxygen species, making the design of excited-state photosensitizers central to its efficacy. Here, π-extended Ru(II) polypyridyl complexes bearing stilbene-functionalized bipyridine ligands were prepared to examine structure–property–activity relationships for one- and two-photon PDT. Variation of substituent electronics (OMe vs NMe2) and the monodentate ligand (Cl- vs SCN-) influenced singlet oxygen quantum yields (ΦΔ), lipophilicity [Log(Do/w)], excited-state emission, two-photon absorption, and light-dependent cytotoxicity in SK-MEL-28 cells. The NMe2 derivatives generally showed stronger photodynamic performance than the OMe analogs, while SCN substitution increased lipophilicity and modulated photophysical behavior. Two-photon absorption (2PA) studies showed moderate 2PA responses for 1b and 2b in the 700–800 nm region, supporting potential NIR activation. Phototoxicity decreased under hypoxia but remained measurable, consistent with an oxygen-dependent PDT mechanism.
Source: ChemRxiv
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7162656845