Cyclometalated and NNN Terpyridine Ruthenium Photocatalysts and Their Cytotoxic Activity.

The cyclometalated terpyridine complexes [Ru(η-OAc)(NC-tpy)(PP)] (PP = dppb , (,)-Skewphos , (,)-Skewphos ) are easily obtained from the acetate derivatives [Ru(η-OAc)(PP)] (PP = dppb, (,)-Skewphos , (,)-Skewphos ) and tpy in methanol by elimination of AcOH. The precursors , are prepared from [Ru(η-OAc)(PPh)] and Skewphos in cyclohexane. Conversely, the NNN complexes [Ru(η-OAc)(NNN-tpy)(PP)]OAc (PP = (,)-Skewphos , (,)-Skewphos ) are synthesized in a one pot reaction from [Ru(η-OAc)(PPh)], PP and tpy in methanol. The neutral NC-tpy , , and cationic NNN-tpy , complexes catalyze the transfer hydrogenation of acetophenone (S/C = 1000) in 2-propanol with NaOPr under light irradiation at 30 °C. Formation of ()-1-phenylethanol has been observed with , in a MeOH/PrOH mixture, whereas the -enantiomer is obtained with , (50-52% ). The tpy complexes show cytotoxic activity against the anaplastic thyroid cancer 8505C and SW1736 cell lines (ED = 0.31-8.53 M), with the cationic displaying an ED of 0.31 M, four times lower compared to the enantiomer .