93166-35-9Relevant academic research and scientific papers
Organometallic Ru(II) Photosensitizers Derived from "-Expansive Cyclometalating Ligands: Surprising Theranostic PDT Effects
Sainuddin, Tariq,McCain, Julia,Pinto, Mitch,Yin, Huimin,Gibson, Jordan,Hetu, Marc,McFarland, Sherri A.
, p. 83 - 95 (2016)
The purpose of the present study was to investigate the influence of "-expansive cyclometalating ligands on the photophysical and photobiological properties of organometallic Ru(II) compounds. Four compounds with increasing " conjugation on the cyclometalating ligand were prepared, and their structures were confirmed by HPLC, 1D and 2D 1H NMR, and mass spectrometry. The properties of these compounds differed substantially from their Ru(II) polypyridyl counterparts. Namely, they were characterized by red-shifted absorption, very weak to no room temperature phosphorescence, extremely short phosphorescence state lifetimes (50 values = 1-2 μM), in agreement with what has traditionally been observed for Ru(II) compounds derived from small C^N ligands. Surprisingly, the complex derived from the most "-expansive cyclometalating ligand exhibited no cytotoxicity in the dark (EC50 > 300 μM) but was phototoxic to cells in the nanomolar regime. Exceptionally large phototherapeutic margins, exceeding 3 orders of magnitude in some cases, were accompanied by bright ligand-centered intracellular fluorescence in cancer cells. Thus, Ru(II) organometallic systems derived from "-expansive cyclometalating ligands, such 4,9,16-triazadibenzo[a,c]napthacene (pbpn), represent the first class of potent light-responsive Ru(II) cyclometalating agents with theranostic potential.
