Hydrogen peroxide assisted photorelease of an anthraquinone-based ligand from [Ru(2,2′-bipyridine)₂(9,10-dioxo-9,10-dihydroanthracen-1-olate)]Cl in aqueous solution

Abstract

A new class of light-activated ruthenium(II) complex was designed as a potential blocker of biological functioning, especially for targeting redox reactions within mitochondria under light activation. Based on our concepts...

The effect of halogenation of salicylaldehyde on the antiproliferative activities of {Δ/Λ-[Ru(bpy)2(X,Y-sal)]BF4} complexes

“…In compound 1 (as a representative example) the HOMO is contributed by the orbitals of the Ruthenium atom (50.7%) and the salicylaldehyde ligand (39.3%) while the LUMO and LUMO+1 are mainly spread over the bpy ligands (see Table S1†) in a similar manner as it has been described for similar complexes 47 or related complexes of ruthenium with bpy ligands and a chelating oxygen donor ligand. 48,49…”

“…In compound 1 (as a representative example) the HOMO is contributed by the orbitals of the Ruthenium atom (50.7%) and the salicylaldehyde ligand (39.3%) while the LUMO and LUMO+1 are mainly spread over the bpy ligands (see Table S1 †) in a similar manner as it has been described for similar complexes 47 or related complexes of ruthenium with bpy ligands and a chelating oxygen donor ligand. 48,49 TD-DFT calculations have been performed to explore the nature of the low-lying singlet and triplet states with the geometries of the ground state. Tables 3 and S2 † summarize the calculated excited states.…”

Recent advances in photorelease complexes for therapeutic applications

“…Perspective lifetimes of only 5-7 ps, were shown to release the anthraquinone ligand in the presence of hydrogen peroxide. 86,87 The decomposition of RU29 would appear to be promoted by an autocatalytic process, which helps explain why it can readily eject the anthraquinone. To date no biological experiments were carried out to ascertain if such complexes would have a therapeutic application.…”

Autocatalytic photodegradation of [Ru(ii)(2,2′-bipyridine)2DAD]+(DADH = 1,2-dihydroxyanthracene-9,10-dione) by hydrogen peroxide under acidic aqueous conditions

“…This process is not accessible in the similar ruthenium complex supporting the non-hydroxyl version of the ligand as reported previously. 7 Deprotonation would leave a quinoidbased ligand as its radical, which can be oxidised by the peroxide present to form the ruthenium(III) complex which is itself an oxidant. It is worth mentioning that the one electron reduction of hydrogen peroxide would also create the strongly oxidising hydroxyl radical (Eqs 3 & 4).…”

“…Our interest in the complex stemmed from previous work, which showed that the simpler version missing the 2-hydroxyl group could be decomposed in the presence of hydrogen peroxide and light. 7 It was not evident if the additional hydroxyl group would serve to promote or retard any photochemical reaction.…”