Photophysical Properties and Singlet Oxygen Production by Ruthenium(II) Complexes of Benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine: Spectroscopic and TD-DFT Study

Foxon, Simon P.; Alamiry, Mohammed A. H.; Walker, Mike G.; Meijer, Anthony J. H. M.; Sazanovich, Igor V.; Weinstein, Julia A.; Thomas, Jim A.

doi:10.1021/jp906716g

Cited by 97 publications

(105 citation statements)

References 57 publications

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“…Polypyridyl complexes 1 a-4 a [31][32][33] and the cyclometalated complex 4 b [34] have been synthesized previously. Complexes 1 b-3 b were synthesized by reacting [Ru(ppy)(bpy)-(NCCH 3 ) 2 ]PF 6 [35] with an equimolar amount of the requisite aromatic ligand in refluxing ethanol.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Comparison Between Polypyridyl and Cyclometalated Ruthenium(II) Complexes: Anticancer Activities Against 2D and 3D Cancer Models

Huang

Zhang

Chen

et al. 2014

Chemistry A European J

122

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The aim of this study was to illustrate the dramatically different anticancer activities between coordinatively saturated polypyridyl (1 a-4 a) and cyclometalated (1 b-4 b) ruthenium(II) complexes. The cyclometalated complexes 1 b-4 b function as DNA transcription inhibitors, exhibiting switch-on cytotoxicity against a 2D cancer cell monolayer, whereas the polypyridyl complexes 1 a-4 a are relatively inactive. Moreover, complexes 1 b-4 b exhibit excellent cytotoxicity against 3D multicellular tumor spheroids (MCTSs), which serve as an intermediate model between in vitro 2D cell monolayers and in vivo 3D solid tumors. The hydrophobicity, efficient cell uptake, and nucleus targeting ability, as well as the high DNA binding affinity of complexes 1 b-4 b, likely contribute to their enhanced anticancer activity. We surmise that cyclometalation could be a universal approach to significantly enhance the anticancer activity of substituted polypyridyl Ru(II) complexes. We also suggest that 3D MCTSs may be a more practical platform for anticancer drug screening than 2D cancer monolayer approaches.

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Section: Synthesis and Characterizationmentioning

confidence: 99%

Comparison Between Polypyridyl and Cyclometalated Ruthenium(II) Complexes: Anticancer Activities Against 2D and 3D Cancer Models

Huang

Zhang

Chen

et al. 2014

Chemistry A European J

122

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“…The presence of long‐lived 3 IL excited states (μs timescale) has been evidenced by time‐resolved spectroscopy coupled with electrochemistry and DFT calculations 29. 30 The relative position of 3 IL with respect to the low‐lying 3 MLCT states may control the photophysics of this class of complexes 29. 30…”

Section: Introductionmentioning

confidence: 99%

Photophysical Properties of Ruthenium(II) Polypyridyl DNA Intercalators: Effects of the Molecular Surroundings Investigated by Theory

Véry

Ambrosek

Otsuka

et al. 2014

Chemistry A European J

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The environmental effects on the structural and photophysical properties of [Ru(L)2 (dppz)](2+) complexes (L=bpy=2,2'-bipyridine, phen=1,10-phenanthroline, tap=1,4,5,8-tetraazaphenanthrene; dppz=dipyrido[3,3-a:2',3'-c]phenazine), used as DNA intercalators, have been studied by means of DFT, time-dependent DFT, and quantum mechanics/molecular mechanics calculations. The electronic characteristics of the low-lying triplet excited states in water, acetonitrile, and DNA have been investigated to decipher the influence of the environment on the luminescent behavior of this class of molecules. The lowest triplet intra-ligand (IL) excited state calculated at λ≈800 nm for the three complexes and localized on the dppz ligand is not very sensitive to the environment and is available for electron transfer from a guanine nucleobase. Whereas the lowest triplet metal-to-ligand charge-transfer ((3)MLCT) states remain localized on the ancillary ligand (tap) in [Ru(tap)2 (dppz)](2+), regardless of the environment, their character is drastically modified in the other complexes [Ru(phen)2 (dppz)](2+) and [Ru(bpy)2 (dppz)](2+) upon going from acetonitrile (MLCTdppz/phen or MLCTdppz/bpy) to water (MLCTdppz) and DNA (MLCTphen and MLCTbpy). The change in the character of the low-lying (3) MLCT states accompanying nuclear relaxation in the excited state controls the emissive properties of the complexes in water, acetonitrile, and DNA. The light-switching effect has been rationalized on the basis of environment-induced control of the electronic density distributed in the lowest triplet excited states.

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“…Therefore, DNA photocleavage experiments were carried out by gel-electrophoresis separation of pBR322 DNA after incubation with 1 -6 and irradiation at 365 nm under aerobic conditions. Near-IR luminescence experiments revealed that the complex is an efficient 1 O 2 sensitizer with yields as high as 83% [54]. However, complex 5 showed potent activity (Fig.…”

mentioning

confidence: 99%

StructureActivity Relationship of Polypyridyl Ruthenium(II) Complexes as DNA Intercalators, DNA Photocleavage Reagents, and DNA Topoisomerase and RNA Polymerase Inhibitors

Chen¹,

Gao²,

Yang³

et al. 2013

Chemistry & Biodiversity

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To investigate the relationship between the molecular structure and biological activity of polypyridyl Ru(II) complexes, such as DNA binding, photocleavage ability, and DNA topoisomerase and RNA polymerase inhibition, six new [Ru(bpy)(2)(dppz)](2+) (bpy=2,2'-bipyridine; dppz=dipyrido[3,2-a:2,',3'-c]phenazine) analogs have been synthesized and characterized by means of (1)H-NMR spectroscopy, mass spectrometry, and elemental analysis. Interestingly, the biological properties of these complexes have been identified to be quite different via a series of experimental methods, such as spectral titration, DNA thermal denaturation, viscosity, and gel electrophoresis. To explain the experimental regularity and reveal the underlying mechanism of biological activity, the properties of energy levels and population of frontier molecular orbitals and excited-state transitions of these complexes have been studied by density-functional theory (DFT) and time-depended DFT (TDDFT) calculations. The results suggest that DNA intercalative ligands with better planarity, greater hydrophobicity, and less steric hindrance are beneficial to the DNA intercalation and enzymatic inhibition of their complexes.

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Photophysical Properties and Singlet Oxygen Production by Ruthenium(II) Complexes of Benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine: Spectroscopic and TD-DFT Study

Cited by 97 publications

References 57 publications

Comparison Between Polypyridyl and Cyclometalated Ruthenium(II) Complexes: Anticancer Activities Against 2D and 3D Cancer Models

Comparison Between Polypyridyl and Cyclometalated Ruthenium(II) Complexes: Anticancer Activities Against 2D and 3D Cancer Models

Photophysical Properties of Ruthenium(II) Polypyridyl DNA Intercalators: Effects of the Molecular Surroundings Investigated by Theory

StructureActivity Relationship of Polypyridyl Ruthenium(II) Complexes as DNA Intercalators, DNA Photocleavage Reagents, and DNA Topoisomerase and RNA Polymerase Inhibitors

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