Synthesis and study of the light absorbing, redox and photophysical properties of Ru(II) and Os(II) complexes of 4,7-diphenyl-1,10-phenanthroline containing the polyazine bridging ligand 2,3-bis(2-pyridyl)pyrazine

Mongelli, Matthew T.; Brewer, Karen J.

doi:10.1016/j.inoche.2006.04.022

Cited by 19 publications

(6 citation statements)

References 31 publications

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“…The four features related to the Ru-sq have the same intensity, which attests that the related redox processes involve the same number of exchanged electrons. By comparison with the data reported in the literature for closely related complexes under similar conditions, ,, the underlying redox processes were assigned as shown in Table S3. The oxidation located at +0.647 V vs SCE can be attributed to the Ru(II)/Ru(III) redox couple, while the sq/cat redox couple can be associated with the first reduction process at −0.249 V vs SCE.…”

Section: Resultsmentioning

confidence: 96%

Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis toIn VivoStudies

et al. 2020

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Chemotherapy remains one of the dominant treatments to cure cancer. However, due to the many inherent drawbacks, there is a surge for new chemotherapeutic drugs. Many classes of compounds have been investigated over the years in order to discover new targets and synergistic mechanisms of action including multicellular targets. In this work, we designed a new chemotherapeutic drug candidate against cancer, namely [Ru(DIP)2(sq)]PF6 (Ru-sq) (DIP = 4,7-diphenyl-1,10-phenanthroline; sq = semiquinonate ligand). The aim was to combine the great potential expressed by Ru(II) polypyridyl complexes and the singular redox and biological properties associated to the catecholate moiety. Experimental evidences (e.g. X-ray crystallography, electron paramagnetic resonance, electrochemistry) demonstrate that the semiquinonate is the preferred oxidation state of the dioxo ligand in this complex. The biological activity of Ru-sq was then scrutinised in vitro and in vivo, and the results highlight the auspicious potential of this complex as a chemotherapeutic agent against cancer.

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Section: Resultsmentioning

confidence: 96%

Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis toIn VivoStudies

et al. 2020

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“…The parent complex 1 has been reported as having a Φ em of 0.023 and found here to have a τ em , of 540 ± 1 ns upon generating the 3 MLCT state. 45 Emission from the Ru(II) 3 MLCT state of 2 is centered at 661 nm (λ ex = 450 nm) and was found to have a Φ em of 0.0059, and an emission lifetime, τ em , of 398 ± 1 ns whereas 3 displayed an emission centered at 663 nm, a Φ em of 0.0011, and τ em of 414 ± 1.0 ns. It is evident from the observed Φ em and τ em for 1, 2, and 3 that covalent attachment of anthracene ligands to 1 is accompanied by quenching of the Ru(II) 3 MLCT.…”

Section: Photophysical Propertiesmentioning

confidence: 99%

“…Excitation of complex 1 at 340 nm yields no emission within the near-UV region, while excitation at λ ex = 450 nm gives rise to an emission band centered at 668 nm, characteristic of the emissive 3 MLCT state common to ruthenium polypyridyl and polyazine complexes. 45 Conversely, excitation of 2 and 3 with λ ex = 340 nm gives rise to emissive high energy transitions with maxima located at 480 nm and a shoulder at 495 nm arising from anthracene singlet excited state relaxation (Figure 4). The anthracene emission from complexes 2 and 3 displays decreased vibronic structure (compared to the vibronically resolved anthracene emission in solution) between 450 -580 nm and is red-shifted relative to the anthracene emission (λ max = 394 nm).…”

Section: Photophysical Propertiesmentioning

confidence: 99%

Pushing the limits of structurally-diverse light-harvesting Ru(II) metal-organic chromophores for photodynamic therapy

Padilla

Maza

Dominijanni

et al. 2016

Journal of Photochemistry and Photobiology A: Chemistry

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The synthesis of Ru(II) derivatives [(AnthbpyMe)(bpy)Ru(dpp)] 2+ (2) and [(AnthbpyMe) 2 Ru(dpp)] 2+ (3), and the analysis of their excited state properties as well as their photocytotoxicity against glioma cells are reported. Complexes 2 and 3 absorb visible light with metal-to-ligand charge transfer (MLCT) transitions at λ max = 459 nm (16,000 M-1 cm-1) and λ max = 461 nm (21,000 M-1 cm-1), respectively. The complexes exhibit bichromatic properties with the 3 MLCT emission centered at λ em = 661 nm and λ em = 663 nm for 2 and 3, respectively, while the anthracene motif(s) has emission from 450-560 nm. The anthracene unit(s) quench the 3 MLCT to give quantum yields (lifetime, τ) of Φ em = 0.0059 (τ = 398 ns) and Φ em = 0.0011 (τ = 414 ns) for 2 and 3, respectively. The quenching rates were found to be 6.61 × 10 5 s-1 for 2 and 5.64 × 10 5 s-1 for 3. Electrochemistry reveals an irreversible anthracene oxidation at 1.23-1.28 V, while the Ru III/II oxidation process occurs at a potential of 1.53-1.55 V. The complexes displayed a quasi-reversible reduction couple attributed to dpp 0/-1 at 0.98 V. Cytotoxicity of both complexes towards F98 glioma cells was moderate in the absence of light and substantially enhanced with visible light.

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“…Spectrophotometric grade acetonitrile was purchased from Spectrum Chemicals. 4,4 0 -Dimethyl ester-2,2 0 -bipyridine (dmeb) [38], [(Ph 2 phen) 2 RuCl 2 ] [39], [(Ph 2 phen) 2 Ru(dpp)](PF 6 ) 2 [40] and [Rh (bpy)Cl 3 (MeOH)](MeOH) [41] were synthesized as previously reported.…”

Section: Methodsmentioning

confidence: 99%

Increased photocatalytic activity in Ru(II),Rh(III) supramolecular bimetallic complexes with terminal ligand substitution

Sayre

White

Brewer

2017

Inorganica Chimica Acta

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a b s t r a c tThree new Ru(II),Rh(III) supramolecular bimetallic complexes of the design [(Ph 2 phen) 2 Ru(dpp)RhCl 2 (R 2 -bpy)](PF 6 ) 3 (R = CH 3 (Ru-Rh(Me 2 bpy)), H (Ru-Rh(bpy)), or COOCH 3 (Ru-Rh(dmeb)); Ph 2 phen = 4, 7-diphenyl-1,10-phenanthroline; dpp = 2,3-bis(2-pyridyl)pyrazine; dmeb = 4,4 0 -dimethyl ester-2,2 0 -bipyridine; bpy = 2,2 0 -bipyridine; Me 2 bpy = 4,4 0 -dimethyl-2,2 0 -bipyridine) have been synthesized and analyzed to determine the impact that the polypyridyl terminal ligand (TL) coordinated to the cis-dihalide rhodium(III) metal center has on the photocatalytic activity for water reduction. The bimetallic complexes demonstrate that a correlation exists between the r-donating ability of the substituted bipyridine ligand, the rate of chloride dissociation upon electrochemical reduction and the activity towards photocatalytic hydrogen production. The weaker r-donating -COOCH 3 substituent in Ru-Rh (dmeb) increases the rate constant for Cl À dissociation (k ÀCl = 0.7 s À1 ) and the amount of H 2 produced photocatalytically (37 ± 4 lmol H 2 , 63 ± 7 turnovers after 20 h; turnovers = mol H 2 /mol photocatalyst) when compared to -H and -CH 3 substituted complexes Ru-Rh(bpy) (k ÀCl = 0.2 s À1 , 21 ± 2 lmol H 2 , 35 ± 3 turnovers) and Ru-Rh(Me 2 bpy) (k ÀCl = 0.2 s À1 , 18 ± 2 lmol H 2 , 30 ± 4 turnovers), respectively. Varied catalytic activity with respect to the r-donor capacity of the Rh-TL is attributed to the relative ease of ligand dissociation and the ability to afford rapid electron collection at the Rh metal center.

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Synthesis and study of the light absorbing, redox and photophysical properties of Ru(II) and Os(II) complexes of 4,7-diphenyl-1,10-phenanthroline containing the polyazine bridging ligand 2,3-bis(2-pyridyl)pyrazine

Cited by 19 publications

References 31 publications

Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis toIn VivoStudies

Ruthenium(II) Complex Containing a Redox-Active Semiquinonate Ligand as a Potential Chemotherapeutic Agent: From Synthesis toIn VivoStudies

Pushing the limits of structurally-diverse light-harvesting Ru(II) metal-organic chromophores for photodynamic therapy

Increased photocatalytic activity in Ru(II),Rh(III) supramolecular bimetallic complexes with terminal ligand substitution

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