1
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Robb MG, Bondì L, Rodríguez-Jiménez S, Garden AL, Jerabek P, Brooker S. Predictable electronic tuning of Fe II and Ru II complexes via choice of azine: correlation of ligand p Ka with Epa(M III/II) of complex. Dalton Trans 2024; 53:1999-2007. [PMID: 38205818 DOI: 10.1039/d3dt03484d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Five new mononuclear ruthenium(II) tris-ligated complexes have been synthesised, varying through the choice of azine in the family of 3-azinyl-4-(4-methylphenyl)-5-phenyl-4H-1,2,4-triazole ligands (Lazine): [Ru(Lpyridine)](PF6)2 (1), [Ru(Lpyridazine)](PF6)2 (2), [Ru(L4-pyrimidine)](PF6)2 (3), [Ru(Lpyrazine)](PF6)2 (4), [Ru(L2-pyrimidine)](PF6)2 (5). Three of them, 1·2MeCN·Et2O, 3·2MeCN·Et2O and 4·2MeCN, have been structurally characterised, confirming the presence of the meridional isomer, as was previously reported for the FeII analogues. Cyclic voltammetry studies, in dry CH3CN vs. Ag/0.01 M AgNO3, show that all five RuII complexes undergo a reversible RuIII/RuII process, with the midpoint potential (Em) increasing from 0.87 to 1.18 V as the azine is changed: pyridine < pyridazine < 2-pyrimidine < 4-pyrimidine < pyrazine. A strong inverse linear correlation (R2 = 0.98) is found between the RuIII/RuII redox potential and the calculated HOMO orbital energies, which is consistent with the expectation that it is easier to oxidise (lower Em) a metal ion with a higher HOMO orbital energy. The same trend was reported earlier for the family of analogous FeII complexes, albeit at lower values of Em in all cases. In addition, the ionisation potentials of the RuII complexes, as well as those of the other group 8 analogues (FeII and OsII), showed a linear relationship with Epa. As the MIII/II redox potentials of a family of complexes has been previously reported to correlate with ligand pKa values, a computational protocol to calculate, in silico, the pKa of the Lazine family of ligands was developed. A strong linear relationship was found between the readily calculated pKa of the Lazine ligand and the Epa of the MII complex, for all three families of complexes (R2 = 0.98).
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Affiliation(s)
- Matthew G Robb
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P. O. Box 56, Dunedin 9054, New Zealand.
| | - Luca Bondì
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P. O. Box 56, Dunedin 9054, New Zealand.
| | - Santiago Rodríguez-Jiménez
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P. O. Box 56, Dunedin 9054, New Zealand.
| | - Anna L Garden
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P. O. Box 56, Dunedin 9054, New Zealand.
| | - Paul Jerabek
- Institute of Hydrogen Technology, Helmholtz Zentrum Hereon, Max Planck-Straße 1, 21502 Geesthacht, Germany.
| | - Sally Brooker
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P. O. Box 56, Dunedin 9054, New Zealand.
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2
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Hernández‐Castillo D, Nau REP, Schmid M, Tschierlei S, Rau S, González L. Mehrere Triplett-Metall-zentrierte Jahn-Teller-Isomere bestimmen die temperaturabhängigen Lumineszenzlebensdauern in [Ru(bpy) 3] 2. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 135:e202308803. [PMID: 38529088 PMCID: PMC10962581 DOI: 10.1002/ange.202308803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Indexed: 03/27/2024]
Abstract
AbstractEin genaues Verständnis der Faktoren, welche die Lumineszenzlebensdauer von Übergangsmetallverbindungen bestimmen, ist für Anwendungen in der Photokatalyse und der photodynamischen Therapie von entscheidender Bedeutung. Die im Falle von [Ru(bpy)3]2+ (bpy=2,2’‐Bipyridin) allgemein akzeptierte Theorie besagt, dass die Emissionslebensdauer durch Optimierung der Energiebarriere zwischen dem emittierenden Triplett‐Zustand des Metall‐Liganden‐Ladungstransfers (3MLCT) und dem thermisch aktivierten Triplett‐Zustand des Metall‐Zentrums (3MC), oder der Energielücke zwischen beiden Zuständen gesteuert werden kann. Hier zeigen wir, dass dies nicht allgemeingültig ist. Darüber hinaus demonstrieren wir, dass die Betrachtung eines einzelnen Relaxationspfades, der vom energetisch niedrigsten Minimum aus bestimmt wird, zu falschen Vorhersagen der temperaturabhängigen Emissionslebensdauer führt. Stattdessen erhalten wir eine ausgezeichnete Übereinstimmung mit den experimentellen temperaturabhängigen Lebensdauern, wenn ein erweitertes kinetisches Modell herangezogen wird, welches alle Pfade im Zusammenhang mit mehreren Jahn–Teller‐Isomeren und ihren effektiven Reaktionsbarrieren beinhaltet. Diese Konzepte sind für das Design weiterer lumineszierender Übergangsmetallkomplexe mit individuell angepassten Emissionslebensdauern auf der Grundlage theoretischer Vorhersagen unerlässlich.
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Affiliation(s)
- David Hernández‐Castillo
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of ViennaWähringer Str. 171090ViennaAustria
- Doctoral School in Chemistry (DoSChem)University of ViennaWähringer Straße 421090ViennaAustria
| | - Roland E. P. Nau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Marie‐Ann Schmid
- Technische Universität BraunschweigDepartment of Energy Conversion, Institute of Physical and Theoretical ChemistryRebenring 3138106BraunschweigGermany
| | - Stefanie Tschierlei
- Technische Universität BraunschweigDepartment of Energy Conversion, Institute of Physical and Theoretical ChemistryRebenring 3138106BraunschweigGermany
| | - Sven Rau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Leticia González
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of ViennaWähringer Str. 171090ViennaAustria
- Vienna Research Platform Accelerating Photoreaction DiscoveryUniversity of ViennaWähringer Straße 171090ViennaAustria
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3
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Hernández‐Castillo D, Nau REP, Schmid M, Tschierlei S, Rau S, González L. Multiple Triplet Metal-Centered Jahn-Teller Isomers Determine Temperature-Dependent Luminescence Lifetimes in [Ru(bpy) 3 ] 2. Angew Chem Int Ed Engl 2023; 62:e202308803. [PMID: 37433755 PMCID: PMC10962642 DOI: 10.1002/anie.202308803] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 07/13/2023]
Abstract
Understanding the factors that determine the luminescence lifetime of transition metal compounds is key for applications in photocatalysis and photodynamic therapy. Here we show that for[ Ru ( bpy ) 3 ] 2 + ${[{\rm{Ru}}({\rm{bpy}})_{\rm{3}} ]^{{\rm{2 + }}} }$ (bpy = 2,2'-bipyridine), the generally accepted idea that emission lifetimes can be controlled optimizing the energy barrier from the emissive triplet metal-to-ligand charge-transfer (3 MLCT) state to the thermally-activated triplet metal-centered (3 MC) state or the energy gap between both states is a misconception. Further, we demonstrate that considering a single relaxation pathway determined from the minimum that is lowest in energy leads to wrong temperature-dependent emission lifetimes predictions. Instead, we obtain excellent agreement with experimental temperature-dependent lifetimes when an extended kinetic model that includes all the pathways related to multiple Jahn-Teller isomers and their effective reaction barriers is employed. These concepts are essential to correctly design other luminescent transition metal complexes with tailored emission lifetimes based on theoretical predictions.
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Affiliation(s)
- David Hernández‐Castillo
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of ViennaWähringer Str. 171090ViennaAustria
- Doctoral School in Chemistry (DoSChem)University of ViennaWähringer Straße 421090ViennaAustria
| | - Roland E. P. Nau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Marie‐Ann Schmid
- Technische Universität BraunschweigDepartment of Energy Conversion, Institute of Physical and Theoretical ChemistryRebenring 3138106BraunschweigGermany
| | - Stefanie Tschierlei
- Technische Universität BraunschweigDepartment of Energy Conversion, Institute of Physical and Theoretical ChemistryRebenring 3138106BraunschweigGermany
| | - Sven Rau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Leticia González
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of ViennaWähringer Str. 171090ViennaAustria
- Vienna Research Platform Accelerating Photoreaction DiscoveryUniversity of ViennaWähringer Straße 171090ViennaAustria
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4
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Blom SJ, Connell TU, Doeven EH, Hayne DJ, Kerr E, Henderson LC, Francis PS. Cathodic Co-reactant Electrogenerated Chemiluminescence of Water-soluble Heteroleptic Iridium(III) Complexes Bearing N–Methyl(pyridyl)pyridinium Cyclometalating Ligands. J Electroanal Chem (Lausanne) 2023. [DOI: 10.1016/j.jelechem.2023.117273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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5
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Dröge F, Noakes FF, Archer SA, Sreedharan S, Raza A, Robertson CC, MacNeil S, Haycock JW, Carson H, Meijer AJHM, Smythe CGW, Bernardino de la Serna J, Dietzek-Ivanšić B, Thomas JA. A Dinuclear Osmium(II) Complex Near-Infrared Nanoscopy Probe for Nuclear DNA. J Am Chem Soc 2021; 143:20442-20453. [PMID: 34808044 DOI: 10.1021/jacs.1c10325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the aim of developing photostable near-infrared cell imaging probes, a convenient route to the synthesis of heteroleptic OsII complexes containing the Os(TAP)2 fragment is reported. This method was used to synthesize the dinuclear OsII complex, [{Os(TAP)2}2tpphz]4+ (where tpphz = tetrapyrido[3,2-a:2',3'-c:3″,2''-h:2‴,3'''-j]phenazine and TAP = 1,4,5,8- tetraazaphenanthrene). Using a combination of resonance Raman and time-resolved absorption spectroscopy, as well as computational studies, the excited state dynamics of the new complex were dissected. These studies revealed that, although the complex has several close lying excited states, its near-infrared, NIR, emission (λmax = 780 nm) is due to a low-lying Os → TAP based 3MCLT state. Cell-based studies revealed that unlike its RuII analogue, the new complex is neither cytotoxic nor photocytotoxic. However, as it is highly photostable as well as live-cell permeant and displays NIR luminescence within the biological optical window, its properties make it an ideal probe for optical microscopy, demonstrated by its use as a super-resolution NIR STED probe for nuclear DNA.
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Affiliation(s)
- Fabian Dröge
- Institute of Physical Chemistry, Helmholtzweg 4, 07743 Jena, Germany; Institute of Photonic Technology Jena e.V., Albert-Einstein-Straße 9, 07749 Jena, Germany
| | | | | | | | | | | | | | | | | | | | | | - Jorge Bernardino de la Serna
- Central Laser Facility, Rutherford Appleton Laboratory, Research Complex at Harwell, Science and Technology Facilities Council, Harwell-Oxford, Didcot OX11 0QX, United Kingdom; National Heart and Lung Institute, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Helmholtzweg 4, 07743 Jena, Germany; Institute of Photonic Technology Jena e.V., Albert-Einstein-Straße 9, 07749 Jena, Germany
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6
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Boota RZ, Hardman SJO, Ashton GP, Rice CR, Scattergood PA, Elliott PIP. Photochemistry of Heteroleptic 1,4,5,8-Tetraazaphenanthrene- and Bi-1,2,3-triazolyl-Containing Ruthenium(II) Complexes. Inorg Chem 2021; 60:15768-15781. [PMID: 34612633 DOI: 10.1021/acs.inorgchem.1c02441] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Diimine metal complexes have significant relevance in the development of photodynamic therapy (PDT) and photoactivated chemotherapy (PACT) applications. In particular, complexes of the TAP ligand (1,4,5,8-tetraazaphenanthrene) are known to lead to photoinduced oxidation of DNA, while TAP- and triazole-based complexes are also known to undergo photochemical ligand release processes relevant to PACT. The photophysical and photochemical properties of heteroleptic complexes [Ru(TAP)n(btz)3-n]2+ (btz = 1,1'-dibenzyl-4,4'-bi-1,2,3-triazolyl, n = 1 (1), 2 (2)) have been explored. Upon irradiation in acetonitrile, 1 displays analogous photochemistry to that previously observed for [Ru(bpy)(btz)2]2+ (bpy = 2,2'-bipyridyl) and generates trans-[Ru(TAP)(btz)(NCMe)2]2+ (5), which has been crystallographically characterized, with the observation of the ligand-loss intermediate trans-[Ru(TAP)(κ2-btz)(κ1-btz)(NCMe)]2+ (4). Complex 2 displays more complicated photochemical behavior with not only preferential photorelease of btz to form cis-[Ru(TAP)2(NCMe)2]2+ (6) but also competitive photorelease of TAP to form 5. Free TAP is then taken up by 6 to form [Ru(TAP)3]2+ (3) with the proportion of 5 and 3 observed to progressively increase during prolonged photolysis. Data suggest a complex set of reversible photochemical ligand scrambling processes in which 2 and 3 are interconverted. Computational DFT calculations have enabled optimization of geometries of the pro-trans 3MCcis states with repelled btz or TAP ligands crucial for the formation of 5 from 1 and 2, respectively, lending weight to recent evidence that such 3MCcis states play an important mechanistic role in the rich photoreactivity of Ru(II) diimine complexes.
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Affiliation(s)
- Rayhaan Z Boota
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Samantha J O Hardman
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K
| | - Gage P Ashton
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Craig R Rice
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul A Scattergood
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul I P Elliott
- Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
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7
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Lechner VM, Nappi M, Deneny PJ, Folliet S, Chu JCK, Gaunt MJ. Visible-Light-Mediated Modification and Manipulation of Biomacromolecules. Chem Rev 2021; 122:1752-1829. [PMID: 34546740 DOI: 10.1021/acs.chemrev.1c00357] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chemically modified biomacromolecules-i.e., proteins, nucleic acids, glycans, and lipids-have become crucial tools in chemical biology. They are extensively used not only to elucidate cellular processes but also in industrial applications, particularly in the context of biopharmaceuticals. In order to enable maximum scope for optimization, it is pivotal to have a diverse array of biomacromolecule modification methods at one's disposal. Chemistry has driven many significant advances in this area, and especially recently, numerous novel visible-light-induced photochemical approaches have emerged. In these reactions, light serves as an external source of energy, enabling access to highly reactive intermediates under exceedingly mild conditions and with exquisite spatiotemporal control. While UV-induced transformations on biomacromolecules date back decades, visible light has the unmistakable advantage of being considerably more biocompatible, and a spectrum of visible-light-driven methods is now available, chiefly for proteins and nucleic acids. This review will discuss modifications of native functional groups (FGs), including functionalization, labeling, and cross-linking techniques as well as the utility of oxidative degradation mediated by photochemically generated reactive oxygen species. Furthermore, transformations at non-native, bioorthogonal FGs on biomacromolecules will be addressed, including photoclick chemistry and DNA-encoded library synthesis as well as methods that allow manipulation of the activity of a biomacromolecule.
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Affiliation(s)
- Vivian M Lechner
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Manuel Nappi
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Patrick J Deneny
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Sarah Folliet
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - John C K Chu
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Matthew J Gaunt
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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8
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Estalayo-Adrián S, Blasco S, Bright SA, McManus GJ, Orellana G, Williams DC, Kelly JM, Gunnlaugsson T. Effect of Alkyl Chain Length on the Photophysical, Photochemical, and Photobiological Properties of Ruthenium(II) Polypyridyl Complexes for Their Application as DNA-Targeting, Cellular-Imaging, and Light-Activated Therapeutic Agents. ACS APPLIED BIO MATERIALS 2021; 4:6664-6681. [PMID: 35006970 DOI: 10.1021/acsabm.1c00284] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A family of six Ru(II) polypyridyl complexes (1-6) which contain phenanthroline-based ligands functionalized with alkyl chains of different lengths (one methyl group, 10 and 21 carbon alkyl chains) and either 1,10-phenanthroline (phen) or 1,4,5,8-tetraazaphenanthrene (TAP) as ancillary ligands have been synthesized and characterized. The influence of the alkyl chain length on their photophysical and photochemical properties as well as in their photobiological applications has been elucidated by monitoring the changes in their MLCT-centered absorption and emission bands. The presence of one methyl group or 10 carbon alkyl chains does not seem to significantly affect the photophysical and photochemical properties of the resulting Ru(II) complexes when compared to the well-known [Ru(phen)3]2+ and [Ru(TAP)2phen]2+. However, an effect on their emission properties and in their ability to photosensitize singlet oxygen is observed for the Ru(II) complexes containing 21 carbon alkyl chains. The binding of these complexes to salmon testes DNA (stDNA) was investigated by observing the changes in the photophysical properties. Complexes 1, 2, 4, and 5 all showed changes in their MLCT bands that could be analyzed using conventional fitting methods, such as the Bard equation. In contrast, complexes 3 and 6, possessing long aliphatic chains, gave rise to nonclassic behavior. In addition to these analyses, both thermal denaturation and circular dichroism studies of 1-6 were carried out in the presence of stDNA which confirmed that these complexes bind to DNA. Confocal microscopy and viability studies in HeLa cervical cancer cells reveal an alkyl chain-length dependence on the cellular uptake and cytotoxicity of the resulting Ru(II) complexes due to an enhancement of their lipophilicity with increasing alkyl chain length. Thus, complexes containing 10 and 21 carbon alkyl chains are rapidly taken up into HeLa cells and, in particular, those with 21 carbon alkyl chains show a significant phototoxicity against the same cell line. Therefore, this study provides further insight into the possible modulation of the photophysical, photochemical, and photobiological properties of Ru(II) polypyridyl complexes by varying the length of the alkyl chains attached to the polypyridyl ligands coordinated to the Ru(II) center and the nature of the auxiliary groups, which we show has a significant effect on photophysical and biological properties.
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Affiliation(s)
- Sandra Estalayo-Adrián
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Salvador Blasco
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Sandra A Bright
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Gavin J McManus
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Guillermo Orellana
- Department of Organic Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, E-28040 Madrid, Spain
| | - D Clive Williams
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - John M Kelly
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Thorfinnur Gunnlaugsson
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
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9
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Cuéllar E, Diez-Varga A, Torroba T, Domingo-Legarda P, Alemán J, Cabrera S, Martín-Alvarez JM, Miguel D, Villafañe F. Luminescent cis-Bis(bipyridyl)ruthenium(II) Complexes with 1,2-Azolylamidino Ligands: Photophysical, Electrochemical Studies, and Photocatalytic Oxidation of Thioethers. Inorg Chem 2021; 60:7008-7022. [PMID: 33905238 PMCID: PMC8812113 DOI: 10.1021/acs.inorgchem.0c03389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New 1,2-azolylamidino complexes cis-[Ru(bipy)2(NH═C(R)az*-κ2N,N)](OTf)2 (R = Me, Ph; az* = pz, indz, dmpz) are synthesized via chloride abstraction after a subsequent base-catalyzed coupling of a nitrile with the previously coordinated 1,2-azole. The synthetic procedure allows the easy obtainment of complexes having different electronic and steric 1,2-azoylamidino ligands. All of the compounds have been characterized by 1H, 13C, and 15N NMR and IR spectroscopy and by monocrystal X-ray diffraction. Photophysical studies support their phosphorescence, whereas their electrochemistry reveals reversible RuII/RuIII oxidations between +1.13 and +1.25 V (vs SCE). The complexes have been successfully used as catalysts in the photooxidation of different thioethers, the complex cis-[Ru(bipy)2(NH═C(Me)dmpz-κ2N,N)]2+ showing better catalytic performance in comparison to that of [Ru(bipy)3]2+. Moreover, the significant catalytic performance of the dimethylpyrazolylamidino complex is applied to the preparation of the drug modafinil, which is obtained using ambient oxygen as an oxidant. Finally, mechanistic assays suggest that the oxidation reaction follows a photoredox route via oxygen radical anion formation.
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Affiliation(s)
- Elena Cuéllar
- GIR MIOMeT-IU Cinquima-Química Inorgánica, Facultad de Ciencias, Campus Miguel Delibes, Universidad de Valladolid, 47011 Valladolid, Spain
| | - Alberto Diez-Varga
- Departamento de Química, Facultad de Ciencias, Universidad de Burgos, 09001 Burgos, Spain
| | - Tomás Torroba
- Departamento de Química, Facultad de Ciencias, Universidad de Burgos, 09001 Burgos, Spain
| | - Pablo Domingo-Legarda
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - José Alemán
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Silvia Cabrera
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Jose M Martín-Alvarez
- GIR MIOMeT-IU Cinquima-Química Inorgánica, Facultad de Ciencias, Campus Miguel Delibes, Universidad de Valladolid, 47011 Valladolid, Spain
| | - Daniel Miguel
- GIR MIOMeT-IU Cinquima-Química Inorgánica, Facultad de Ciencias, Campus Miguel Delibes, Universidad de Valladolid, 47011 Valladolid, Spain
| | - Fernando Villafañe
- GIR MIOMeT-IU Cinquima-Química Inorgánica, Facultad de Ciencias, Campus Miguel Delibes, Universidad de Valladolid, 47011 Valladolid, Spain
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10
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Estalayo-Adrián S, McManus GJ, Dalton HL, Savyasachi AJ, Kelly JM, Gunnlaugsson T. Functionalisation of gold nanoparticles with ruthenium(II) polypyridyl complexes for their application in cellular imaging. Dalton Trans 2020; 49:14158-14168. [PMID: 33021298 DOI: 10.1039/d0dt02754e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new dinuclear Ru(ii) polypyridyl complexes containing an alkyl disulphide functionalised bipyridine-based ligand and either 1,10-phenanthroline (phen) or 1,4,5,8-tetraazaphenanthrene (TAP) as ancillary ligands have been synthesised and characterised. Their attachment onto the surface of gold nanoparticles (AuNPs, average diameter of ca. 2.5 nm) resulted in the formation of two new water-soluble Ru(ii)-AuNP conjugates that combine the advantageous properties of both moieties. Both free complexes show the attractive photophysical properties of Ru(ii) polypyridyl complexes and a rapid cellular uptake in HeLa cervical cancer cells. However, their corresponding gold conjugates displayed lower quantum yields than those determined for the free complexes presumed to be due to an energy transfer quenching of the Ru(ii) luminescence by interaction with the gold surface. Despite their diminished luminescence, confocal fluorescence microscopy studies revealed that the Ru(ii)-AuNP conjugates are successfully internalised into HeLa cells and better tolerated than their free complex counterparts after 24 h incubation, which makes them potential luminescent nanomaterials for bioimaging applications.
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Affiliation(s)
- Sandra Estalayo-Adrián
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland. and Advanced Materials and BioEngineering Research (AMBER) Centre, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Gavin J McManus
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - Hannah L Dalton
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
| | - Aramballi J Savyasachi
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
| | - John M Kelly
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
| | - Thorfinnur Gunnlaugsson
- School of Chemistry and Trinity Biomedical Sciences Institute (TBSI), Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
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11
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Cullinane D, Gkika KS, Byrne A, Keyes TE. Photostable NIR emitting ruthenium(II) conjugates; uptake and biological activity in live cells. J Inorg Biochem 2020; 207:111032. [PMID: 32311630 DOI: 10.1016/j.jinorgbio.2020.111032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 01/19/2023]
Abstract
A photostable Ru(2,2-biquinoline)2(3-(2-pyridyl)-5-(4-carboxyphenyl)-1,2,4-triazolate) (Ru(biq)2(trzbenzCOOH)) complex that exhibits near-infrared (NIR) emission centred at 786 nm is reported. The parent complex was conjugated via amide coupling to a cell-penetrating peptide sequence octa-arginine (R8), and two signal peptide sequences; the nuclear localizing sequence (NLS) VQRKRQKLMP and the mitochondria penetrating peptide (MPP) FrFKFrFK(Ac) (r = D isomer of arginine, Ac = terminal lysine amine acetyl blocked). Notably, none of the peptide conjugates were cell-permeable as chloride salts but efficient and rapid membrane permeation was observed post ion exchange with perchlorate counterion. Also, surprisingly, all three peptide conjugates exhibited potent dark cytotoxicity in both CHO and HeLa cell lines. The peptide conjugates induce cell death through a caspase dependent apoptotic pathway. At the minimum concentration of dye (approx. 15 μM) required for cell imaging, only 20% of the cells were viable after a 24 h incubation period. To overcome cytotoxicity, the parent complex was PEGylated; this dramatically decreased cytotoxicity, where 50% of cells were viable even at 150 μM concentration after 24 h. Confocal luminescence microscopy indicated that all four bioconjugates, peptides in perchlorate form and polyethylene glycol (PEG) in chloride form, were rapidly internalized within the cell. However, interestingly the precise localisation by the signal peptides observed in related complexes was not observed here and the peptide conjugates were unsuitable as luminescent probes for cell microscopy due to their high cell toxicity. The poor targeting of signal peptides in this instance is attributed to the high lipophilicity of the metal centre.
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Affiliation(s)
- David Cullinane
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Karmel Sofia Gkika
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Aisling Byrne
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Tia E Keyes
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
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12
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Weynand J, Moreno-Betancourt A, Loiseau F, Berthet N, Defrancq E, Elias B. Redox-Active Bis-Cyclometalated Iridium(III) Complex as a DNA Photo-Cleaving Agent. Inorg Chem 2020; 59:2426-2433. [PMID: 31977196 DOI: 10.1021/acs.inorgchem.9b03312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The development of new photoactive metal complexes that can trigger oxidative damages to the genetic material is of great interest. In the present paper, we describe the detailed study of a highly photo-oxidant iridium(III) complex that triggers photoinduced electron transfer (PET) with purine DNA bases. The PET has been studied by luminescence and laser flash photolysis experiments. From plasmid DNA agarose gel electrophoresis experiments, we demonstrated the high ability of the iridium complex to induce strand breaks upon light irradiation. Reactive oxygen species (ROS)-specific scavengers and stabilizers were employed to identify that the photocleavage process, the results of which infer singlet oxygen and hydrogen peroxide as the predominant species. To the best of our knowledge, the present work represents one of the few study for highly photo-oxidant bis-cyclometalated iridium(III) complex toward DNA.
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Affiliation(s)
- Justin Weynand
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis Division (MOST) , Université catholique de Louvain (UCLouvain) , Place Louis Pasteur 1, bte L4.01.02 , B-1348 Louvain-la-Neuve , Belgium.,Département de Chimie Moléculaire, UMR CNRS 5250 , Université Grenoble Alpes , CS 40700, 38058 Grenoble , France
| | - Angélica Moreno-Betancourt
- Département de Chimie Moléculaire, UMR CNRS 5250 , Université Grenoble Alpes , CS 40700, 38058 Grenoble , France
| | - Frédérique Loiseau
- Département de Chimie Moléculaire, UMR CNRS 5250 , Université Grenoble Alpes , CS 40700, 38058 Grenoble , France
| | - Nathalie Berthet
- Département de Chimie Moléculaire, UMR CNRS 5250 , Université Grenoble Alpes , CS 40700, 38058 Grenoble , France
| | - Eric Defrancq
- Département de Chimie Moléculaire, UMR CNRS 5250 , Université Grenoble Alpes , CS 40700, 38058 Grenoble , France
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis Division (MOST) , Université catholique de Louvain (UCLouvain) , Place Louis Pasteur 1, bte L4.01.02 , B-1348 Louvain-la-Neuve , Belgium
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13
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Bevernaegie R, Wehlin SAM, Piechota EJ, Abraham M, Philouze C, Meyer GJ, Elias B, Troian-Gautier L. Improved Visible Light Absorption of Potent Iridium(III) Photo-oxidants for Excited-State Electron Transfer Chemistry. J Am Chem Soc 2020; 142:2732-2737. [DOI: 10.1021/jacs.9b12108] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robin Bevernaegie
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Sara A. M. Wehlin
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Eric J. Piechota
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Michael Abraham
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Christian Philouze
- Département de Chimie Moléculaire, Université Grenoble-Alpes (UGA), UMR CNRS 5250, CS 40700, 38058 Grenoble, France
| | - Gerald J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Benjamin Elias
- UCLouvain, Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Place Louis Pasteur 1, box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Ludovic Troian-Gautier
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
- Laboratoire de Chimie Organique, Université Libre de Bruxelles (ULB), CP 160/06, 50 avenue F.D. Roosevelt, B-1050 Brussels, Belgium
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14
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da Silva MRE, Auvray T, Hanan GS. Synthesis of a novel bipyrimidine dicarboxylic acid ligand for the preparation of panchromatic ruthenium dyes. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2019.119194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Whole microwave syntheses of pyridylpyrazole and of Re and Ru luminescent pyridylpyrazole complexes. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2018.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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16
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Rodríguez‐Jiménez S, Bondì L, Yang M, Garden AL, Brooker S. Predictable Electronic Tuning By Choice of Azine Substituent in Five Iron(II) Triazoles: Redox Properties and DFT Calculations. Chem Asian J 2018; 14:1158-1166. [PMID: 30550630 DOI: 10.1002/asia.201801537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/13/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Santiago Rodríguez‐Jiménez
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and NanotechnologyUniversity of Otago P.O. Box 56 Dunedin 9054 New Zealand
| | - Luca Bondì
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and NanotechnologyUniversity of Otago P.O. Box 56 Dunedin 9054 New Zealand
| | - Mingrui Yang
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and NanotechnologyUniversity of Otago P.O. Box 56 Dunedin 9054 New Zealand
| | - Anna L. Garden
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and NanotechnologyUniversity of Otago P.O. Box 56 Dunedin 9054 New Zealand
| | - Sally Brooker
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and NanotechnologyUniversity of Otago P.O. Box 56 Dunedin 9054 New Zealand
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17
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McQuaid K, Hall JP, Brazier JA, Cardin DJ, Cardin CJ. X-ray Crystal Structures Show DNA Stacking Advantage of Terminal Nitrile Substitution in Ru-dppz Complexes. Chemistry 2018; 24:15859-15867. [DOI: 10.1002/chem.201803021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/26/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Kane McQuaid
- Department of Chemistry; University of Reading; Whiteknights Reading RG6 6AD UK
- Diamond Light Source; Harwell Science and Innovation Campus; Didcot Oxfordshire OX11 0DE UK
| | - James P. Hall
- Department of Chemistry; University of Reading; Whiteknights Reading RG6 6AD UK
- Department of Pharmacy; University of Reading; Whiteknights Reading RG6 6AD UK
- Diamond Light Source; Harwell Science and Innovation Campus; Didcot Oxfordshire OX11 0DE UK
| | - John A. Brazier
- Department of Pharmacy; University of Reading; Whiteknights Reading RG6 6AD UK
| | - David J. Cardin
- Department of Chemistry; University of Reading; Whiteknights Reading RG6 6AD UK
| | - Christine J. Cardin
- Department of Chemistry; University of Reading; Whiteknights Reading RG6 6AD UK
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18
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Troian-Gautier L, Wehlin SAM, Meyer GJ. Photophysical Properties of Tetracationic Ruthenium Complexes and Their Ter-Ionic Assemblies with Chloride. Inorg Chem 2018; 57:12232-12244. [DOI: 10.1021/acs.inorgchem.8b01921] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ludovic Troian-Gautier
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Sara A. M. Wehlin
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Gerald J. Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
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19
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Bevernaegie R, Marcélis L, Laramée-Milette B, De Winter J, Robeyns K, Gerbaux P, Hanan GS, Elias B. Trifluoromethyl-Substituted Iridium(III) Complexes: From Photophysics to Photooxidation of a Biological Target. Inorg Chem 2018; 57:1356-1367. [PMID: 29336560 DOI: 10.1021/acs.inorgchem.7b02778] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Photodynamic therapeutic agents are of key interest in developing new strategies to develop more specific and efficient anticancer treatments. In comparison to classical chemotherapeutic agents, the activity of photodynamic therapeutic compounds can be finely controlled thanks to the light triggering of their photoreactivity. The development of type I photosensitizing agents, which do not rely on the production of ROS, is highly desirable. In this context, we developed new iridium(III) complexes which are able to photoreact with biomolecules; namely, our Ir(III) complexes can oxidize guanine residues under visible light irradiation. We report the synthesis and extensive photophysical characterization of four new Ir(III) complexes, [Ir(ppyCF3)2(N^N)]+ [ppyCF3 = 2-(3,5-bis(trifluoromethyl)phenyl)pyridine) and N^N = 2,2'-dipyridyl (bpy); 2-(pyridin-2-yl)pyrazine (pzpy); 2,2'-bipyrazine (bpz); 1,4,5,8-tetraazaphenanthrene (TAP)]. In addition to an extensive experimental and theoretical study of the photophysics of these complexes, we characterize their photoreactivity toward model redox-active targets and the relevant biological target, the guanine base. We demonstrate that photoinduced electron transfer takes place between the excited Ir(III) complex and guanine which leads to the formation of stable photoproducts, indicating that the targeted guanine is irreversibly damaged. These results pave the way to the elaboration of new type I photosensitizers for targeting cancerous cells.
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Affiliation(s)
- Robin Bevernaegie
- Université catholique de Louvain (UCL) , Institut de la Matière Condensée et des Nanosciences (IMCN), Place Louis Pasteur, 1 box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Lionel Marcélis
- Université catholique de Louvain (UCL) , Institut de la Matière Condensée et des Nanosciences (IMCN), Place Louis Pasteur, 1 box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Baptiste Laramée-Milette
- Département de Chimie, Université de Montréal , Pavillon J.-A. Bombardier, 5155 Chemin de la Rampe, Montréal, Québec H3T 2B1, Canada
| | - Julien De Winter
- Organic Synthesis and Mass Spectrometry Laboratory, University of Mons - UMons , 23 Place du Parc, B-7000 Mons, Belgium
| | - Koen Robeyns
- Université catholique de Louvain (UCL) , Institut de la Matière Condensée et des Nanosciences (IMCN), Place Louis Pasteur, 1 box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory, University of Mons - UMons , 23 Place du Parc, B-7000 Mons, Belgium
| | - Garry S Hanan
- Département de Chimie, Université de Montréal , Pavillon J.-A. Bombardier, 5155 Chemin de la Rampe, Montréal, Québec H3T 2B1, Canada
| | - Benjamin Elias
- Université catholique de Louvain (UCL) , Institut de la Matière Condensée et des Nanosciences (IMCN), Place Louis Pasteur, 1 box L4.01.02, B-1348 Louvain-la-Neuve, Belgium
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20
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Michaudel Q, Chauviré T, Kottisch V, Supej MJ, Stawiasz KJ, Shen L, Zipfel WR, Abruña HD, Freed JH, Fors BP. Mechanistic Insight into the Photocontrolled Cationic Polymerization of Vinyl Ethers. J Am Chem Soc 2017; 139:15530-15538. [PMID: 28985061 PMCID: PMC5806523 DOI: 10.1021/jacs.7b09539] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mechanism of the recently reported photocontrolled cationic polymerization of vinyl ethers was investigated using a variety of catalysts and chain-transfer agents (CTAs) as well as diverse spectroscopic and electrochemical analytical techniques. Our study revealed a complex activation step characterized by one-electron oxidation of the CTA. This oxidation is followed by mesolytic cleavage of the resulting radical cation species, which leads to the generation of a reactive cation-this species initiates the polymerization of the vinyl ether monomer-and a dithiocarbamate radical that is likely in equilibrium with the corresponding thiuram disulfide dimer. Reversible addition-fragmentation type degenerative chain transfer contributes to the narrow dispersities and control over chain growth observed under these conditions. Finally, the deactivation step is contingent upon the oxidation of the reduced photocatalyst by the dithiocarbamate radical concomitant with the production of a dithiocarbamate anion that caps the polymer chain end. The fine-tuning of the electronic properties and redox potentials of the photocatalyst in both the excited and the ground states is necessary to obtain a photocontrolled system rather than simply a photoinitiated system. The elucidation of the elementary steps of this process will aid the design of new catalytic systems and their real-world applications.
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Affiliation(s)
| | | | | | | | | | - Luxi Shen
- Cornell University, Ithaca, New York 14853, United States
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21
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Wehlin SAM, Troian-Gautier L, Li G, Meyer GJ. Chloride Oxidation by Ruthenium Excited-States in Solution. J Am Chem Soc 2017; 139:12903-12906. [PMID: 28853874 DOI: 10.1021/jacs.7b06762] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photodriven HCl splitting to produce solar fuels is an important goal that requires strong photo-oxidants capable of chloride oxidation. In a molecular approach toward this goal, three ruthenium compounds with 2,2'-bipyrazine backbones were found to oxidize chloride ions in acetone solution. Nanosecond transient absorption measurements provide compelling evidence for excited-state electron transfer from chloride to the Ru metal center with rate constants in excess of 1010 M-1 s-1. The Cl atom product was trapped with an olefin. This reactivity was promoted through pre-organization of ground-state precursors in ion pairs. Chloride oxidation with a tetra-cationic ruthenium complex was most favorable, as the dicationic complexes were susceptible to photochemical ligand loss. Marcus analysis afforded an estimate of the chlorine formal reduction potential E°(Cl•/-) = 1.87 V vs NHE that is at least 300 meV more favorable than the accepted values in water.
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Affiliation(s)
- Sara A M Wehlin
- Department of Chemistry, University of North Carolina at Chapel Hill , Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Ludovic Troian-Gautier
- Department of Chemistry, University of North Carolina at Chapel Hill , Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Guocan Li
- Department of Chemistry, University of North Carolina at Chapel Hill , Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
| | - Gerald J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill , Murray Hall 2202B, Chapel Hill, North Carolina 27599-3290, United States
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22
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Molaee H, Nabavizadeh SM, Jamshidi M, Vilsmeier M, Pfitzner A, Samandar Sangari M. Phosphorescent heterobimetallic complexes involving platinum(iv) and rhenium(vii) centers connected by an unsupported μ-oxido bridge. Dalton Trans 2017; 46:16077-16088. [DOI: 10.1039/c7dt03126b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Heterobimetallic compounds containing an unsupported Pt(iv)–O–Re(vii) bridge are synthesized. The complexes exhibit rare phosphorescence emission in solid and frozen states.
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Affiliation(s)
- Hajar Molaee
- Department of Chemistry
- College of Sciences
- Shiraz University
- Shiraz
- Iran
| | | | | | - Max Vilsmeier
- Institut für Anorganische Chemie
- Universität Regensburg
- 93040 Regensburg
- Germany
| | - Arno Pfitzner
- Institut für Anorganische Chemie
- Universität Regensburg
- 93040 Regensburg
- Germany
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