168646-53-5Relevant articles and documents
Stepwise Syntheses of Mono- and Di-nuclear Ruthenium tpphz Complexes 2- and 4+ phenazine>
Bolger, Joseph,Gourdon, Andre,Ishow, Elena,Launay, Jean-Pierre
, p. 1799 - 1800 (1995)
The complex 2+ (tpphz = tetrapyridophenazine), is obtained by reaction of 2+ with 5,6-diamino-1,10-phenanthroline; upon reaction with 2+, the fully conjugated dimer 4+ is obtained.
Low quantum yields of relaxed electron transfer products of moderately coupled ruthenium(II)-cobalt(III) compounds on the subpicosecond laser excitation
Torieda, Hiroaki,Nozaki, Koichi,Yoshimura, Akio,Ohno, Takeshi
, p. 4819 - 4829 (2004)
Photoinduced electron-transfer reactions of [(tpy)RuII(tpy-tpy) CoIII(tpy)]5+ (tpy = 2,2′:6′,2″-terpyridine and tpy-tpy = 6′,6″-bis(2-pyridyl)-2,2′:4′,4″: 2″,2″′-quarterpyridyne), [(tpy)RuII(tpy-ph-tpy) CoIII(tpy)]5+ (tpy-ptitpy = 1,4-bis[2,2′:6′,2″- terpyridine-4′-yl]benzene), and [(bpy)2RuII(tpphz) CoIII(bpy)2]5+ (bpy = 2,2′-bipyridine, and tpphz = tetrapyrido[3,2-a:2′,3′-c:3″,2″-h:: 2″′,3″′-j]phenazine) were studied in the range 140-298 K by means of subpicosecond transient absorption spectroscopy. 3MLCT(Ru) of [(tpy)RuII(L-L)CoIII(tpy)] 5+ (L-L: tpy-tpy and tpy-ph-tpy) underwent intramolecular electron-transfer (EET) reaction to form [2RuIII(tpy)(L-L) 2CoII(tpy)]5+ in a shorter time than 10 ps. Low quantum yields of the EET products (0.53 for tpy-tpy and 0.41 for tpy-ph-tpy in butyronitrile at 298 K) measured before the fast return electron-transfer were found as in the intermolecular electron-transfer quenching of 3MLCT(Ru) by [Co(tpy)2]3+. The quantum yield of [(tpy)-RuIII(tpy-tpy)CoII(tpy)]5+ (Φ) decreases to 0.38 in a slowly reorganizing solvent of propylene carbonate and that of [(tpy)RuII(tpy-ph-tpy)CoIII(tpy)]5+ to 0.21 at 180 K. The reductions in the EET yields, 1 - Φ, can be ascribed to a fast transition of the nonrelaxed EET product to the lowest triplet d-d* state of [CoIII(tpy)2] moiety during the solvent reorganization. A tunneling transition of the nonrelaxed EET products to the lowest lying d-d excited-state of [CoIII(tpy)2] moiety takes place as a hole transfer, HT, from the dπ-orbital of Ru(III) to that of Co(II) with a configuration of dπ6da*. An electronic coupling of dπ(Ru)-dπ(Co) estimated from the intensity of inter-valence transition of [(tpy)RuIII(L-L)RuII(tpy)]5+ (Collin, J.-P.; Laine, P.; Launay, J.-P.; Sauvage, J.-P.; Sour, A. J. Chem. Soc., Chem. Commun. 1993, 434) is large enough to carry out the HT. The weak coupling of dπ(Ru)-dπ(Co) in the case of [(bpy)2Ru(tpphz) Co(bpy)2]5+ attenuates the HT rate to bring about a high yield of EET (0.8). The possibility that energy-transfer of 3MLCT(Ru) to the Co(III) moiety via an intermediate super-exchange coupling between dπ(Ru) and dπ(Co) occurs in competition with the EET of [(tpy)Ru III(tpy-ph-tpy)CoII(tpy)]5+ is also pursued.
Half-subtractor operation in pH responsive N-heterocyclic amines
Suresh, Moorthy,Ghosh, Amrita,Das, Amitava
, p. 8205 - 8208 (2007)
Intramolecular charge transfer processes in simple molecules can be exploited to implement combinational digital operation.
Flexible RuII Schiff Base Complexes: G-Quadruplex DNA Binding and Photo-Induced Cancer Cell Death
Gillard, Martin,Weynand, Justin,Bonnet, Hugues,Loiseau, Frédérique,Decottignies, Anabelle,Dejeu, Jér?me,Defrancq, Eric,Elias, Benjamin
supporting information, p. 13849 - 13860 (2020/10/02)
A series of new RuII Schiff base complexes built on the salphen moiety has been prepared. This includes four flexible monometallic RuII compounds and six rigid bimetallic analogues that contain NiII, PdII or PtII cations into the salphen complexation site. Steady state luminescence titrations illustrated the capacity of the compounds to photoprobe G-quadruplex (G4) DNA. Moreover, the vast array of the Schiff base structural changes allowed to extensively assess the influence of the ligand surface, flexibility and charge on the interaction of the compounds with G4 DNA. This was achieved thanks to circular dichroism melting assays and bio-layer interferometry studies that pointed up high affinities along with good selectivities of RuII Schiff base complexes for G4 DNA. In cellulo studies were carried out with the most promising compounds. Cellular uptake with location of the compounds in the nucleus as well as in the nucleolus was observed. Cell viability experiments were performed with U2OS osteosarcoma cells in the dark and under light irradiation which allowed the measurements of IC50 values and photoindexes. They showed the substantial role played by light irradiation in the activity of the drugs in addition to the low cytotoxicity of the molecules in the dark. Altogether, the reported results emphasize the promising properties of RuII Schiff base complexes as a new class of candidates for developing potential G4 DNA targeting diagnostic or therapeutic compounds.