1
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Sinha N, Wellauer J, Maisuradze T, Prescimone A, Kupfer S, Wenger OS. Reversible Photoinduced Ligand Substitution in a Luminescent Chromium(0) Complex. J Am Chem Soc 2024; 146:10418-10431. [PMID: 38588581 PMCID: PMC11027151 DOI: 10.1021/jacs.3c13925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024]
Abstract
Light-triggered dissociation of ligands forms the basis for many compounds of interest for photoactivated chemotherapy (PACT), in which medicinally active substances are released or "uncaged" from metal complexes upon illumination. Photoinduced ligand dissociation is usually irreversible, and many recent studies performed in the context of PACT focused on ruthenium(II) polypyridines and related heavy metal complexes. Herein, we report a first-row transition metal complex, in which photoinduced dissociation and spontaneous recoordination of a ligand unit occurs. Two scorpionate-type tridentate chelates provide an overall six-coordinate arylisocyanide environment for chromium(0). Photoexcitation causes decoordination of one of these six ligating units and coordination of a solvent molecule, at least in tetrahydrofuran and 1,4-dioxane solvents, but far less in toluene, and below detection limit in cyclohexane. Transient UV-vis absorption spectroscopy and quantum chemical simulations point to photoinduced ligand dissociation directly from an excited metal-to-ligand charge-transfer state. Owing to the tridentate chelate design and the substitution lability of the first-row transition metal, recoordination of the photodissociated arylisocyanide ligand unit can occur spontaneously on a millisecond time scale. This work provides insight into possible self-healing mechanisms counteracting unwanted photodegradation processes and seems furthermore relevant in the contexts of photoswitching and (photo)chemical information storage.
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Affiliation(s)
- Narayan Sinha
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
- School
of Chemical Sciences, Indian Institute of
Technology Mandi, Mandi 175075, Himachal Pradesh, India
| | - Joël Wellauer
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Tamar Maisuradze
- Institute
of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Alessandro Prescimone
- Department
of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Stephan Kupfer
- Institute
of Physical Chemistry, Friedrich Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Oliver S. Wenger
- Department
of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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2
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Dunbar MN, Steinke SJ, Piechota EJ, Turro C. Differences in Photophysical Properties and Photochemistry of Ru(II)-Terpyridine Complexes of CH 3CN and Pyridine. J Phys Chem A 2024; 128:599-610. [PMID: 38227956 DOI: 10.1021/acs.jpca.3c07432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
A series of 22 Ru(II) complexes of the type [Ru(tpy)(L)(L')]n+, where tpy is the tridentate ligand 2,2';6,2″-terpyridine, L represents bidentate ligands with varying electron-donating ability, and L' is acetonitrile (1a-11a) or pyridine (1b-11b), were investigated. The dissociation of acetonitrile occurs from the 3MLCT state in 1a-11a, such that it does not require the population of a 3LF state. Electrochemistry and spectroscopic data demonstrate that the ground states of these series do not differ significantly. Franck-Condon line-shape analysis of the 77 K emission data shows no significant differences between the emitting 3MLCT states in both series. Arrhenius analysis of the temperature dependence of 3MLCT lifetimes shows that the energy barrier (Ea) to thermally populating a 3LF state from a lower energy 3MLCT state is significantly higher in the pyridine than in the CH3CN series, consistent with the photostability of complexes 1b-11b, which do not undergo pyridine photodissociation under our experimental conditions. Importantly, these results demonstrate that ligand photodissociation of pyridine in 1b-11b does not take place directly from the 3MLCT state, as is the case for 1a-11a. These findings have potential impact on the rational design of complexes for a number of applications, including photochemotherapy, dye-sensitized solar cells, and photocatalysis.
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Affiliation(s)
- Marilyn N Dunbar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Sean J Steinke
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Eric J Piechota
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Claudia Turro
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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3
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Abstract
Ruthenium(II) polypyridyl complexes form a vast family of molecules characterized by their finely tuned photochemical and photophysical properties. Their ability to undergo excited-state deactivation via photosubstitution reactions makes them quite unique in inorganic photochemistry. As a consequence, they have been used, in general, for building dynamic molecular systems responsive to light but, more particularly, in the field of oncology, as prodrugs for a new cancer treatment modality called photoactivated chemotherapy (PACT). Indeed, the ability of a coordination bond to be selectively broken under visible light irradiation offers fascinating perspectives in oncology: it is possible to make poorly toxic agents in the dark that become activated toward cancer cell killing by simple visible light irradiation of the compound inside a tumor. In this Perspective, we review the most important concepts behind the PACT idea, the relationship between ruthenium compounds used for PACT and those used for a related phototherapeutic approach called photodynamic therapy (PDT), and we discuss important questions about real-life applications of PACT in the clinic. We conclude this Perspective with important challenges in the field and an outlook.
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Affiliation(s)
- Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC Leiden, The Netherlands
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4
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Kitzmann WR, Bertrams MS, Boden P, Fischer AC, Klauer R, Sutter J, Naumann R, Förster C, Niedner-Schatteburg G, Bings NH, Hunger J, Kerzig C, Heinze K. Stable Molybdenum(0) Carbonyl Complex for Upconversion and Photoredox Catalysis. J Am Chem Soc 2023. [PMID: 37478053 DOI: 10.1021/jacs.3c03832] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Photoactive complexes with earth-abundant metals have attracted increasing interest in the recent years fueled by the promise of sustainable photochemistry. However, sophisticated ligands with complicated syntheses are oftentimes required to enable photoactivity with nonprecious metals. Here, we combine a cheap metal with simple ligands to easily access a photoactive complex. Specifically, we synthesize the molybdenum(0) carbonyl complex Mo(CO)3(tpe) featuring the tripodal ligand 1,1,1-tris(pyrid-2-yl)ethane (tpe) in two steps with a high overall yield. The complex shows intense deep-red phosphorescence with excited state lifetimes of several hundred nanoseconds. Time-resolved infrared spectroscopy and laser flash photolysis reveal a triplet metal-to-ligand charge-transfer (3MLCT) state as the lowest excited state. Temperature-dependent luminescence complemented by density functional theory (DFT) calculations suggest thermal deactivation of the 3MLCT state via higher lying metal-centered states in analogy to the well-known photophysics of [Ru(bpy)3]2+. Importantly, we found that the title compound is very photostable due to the lack of labilized Mo-CO bonds (as caused by trans-coordinated CO) in the facial configuration of the ligands. Finally, we show the versatility of the molybdenum(0) complex in two applications: (1) green-to-blue photon upconversion via a triplet-triplet annihilation mechanism and (2) photoredox catalysis for a green-light-driven dehalogenation reaction. Overall, our results establish tripodal carbonyl complexes as a promising design strategy to access stable photoactive complexes of nonprecious metals avoiding tedious multistep syntheses.
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Affiliation(s)
- Winald R Kitzmann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Maria-Sophie Bertrams
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Pit Boden
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Alexander C Fischer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - René Klauer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Sutter
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Christoph Förster
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Gereon Niedner-Schatteburg
- Department of Chemistry and State Research Center OPTIMAS, RPTU Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern-Landau, Germany
| | - Nicolas H Bings
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Johannes Hunger
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Katja Heinze
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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5
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Hakkennes MLA, Meijer MS, Menzel JP, Goetz AC, Van Duijn R, Siegler MA, Buda F, Bonnet S. Ligand Rigidity Steers the Selectivity and Efficiency of the Photosubstitution Reaction of Strained Ruthenium Polypyridyl Complexes. J Am Chem Soc 2023. [PMID: 37294954 DOI: 10.1021/jacs.3c03543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
While photosubstitution reactions in metal complexes are usually thought of as dissociative processes poorly dependent on the environment, they are, in fact, very sensitive to solvent effects. Therefore, it is crucial to explicitly consider solvent molecules in theoretical models of these reactions. Here, we experimentally and computationally investigated the selectivity of the photosubstitution of diimine chelates in a series of sterically strained ruthenium(II) polypyridyl complexes in water and acetonitrile. The complexes differ essentially by the rigidity of the chelates, which strongly influenced the observed selectivity of the photosubstitution. As the ratio between the different photoproducts was also influenced by the solvent, we developed a full density functional theory modeling of the reaction mechanism that included explicit solvent molecules. Three reaction pathways leading to photodissociation were identified on the triplet hypersurface, each characterized by either one or two energy barriers. Photodissociation in water was promoted by a proton transfer in the triplet state, which was facilitated by the dissociated pyridine ring acting as a pendent base. We show that the temperature variation of the photosubstitution quantum yield is an excellent tool to compare theory with experiments. An unusual phenomenon was observed for one of the compounds in acetonitrile, for which an increase in temperature led to a surprising decrease in the photosubstitution reaction rate. We interpret this experimental observation based on complete mapping of the triplet hypersurface of this complex, revealing thermal deactivation to the singlet ground state through intersystem crossing.
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Affiliation(s)
- Matthijs L A Hakkennes
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Michael S Meijer
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Jan Paul Menzel
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Anne-Charlotte Goetz
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Roy Van Duijn
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Maxime A Siegler
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, Maryland 21218, United States
| | - Francesco Buda
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, Leiden 2300 RA, The Netherlands
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6
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He G, He M, Wang R, Li X, Hu H, Wang D, Wang Z, Lu Y, Xu N, Du J, Fan J, Peng X, Sun W. A Near‐Infrared Light‐Activated Photocage Based on a Ruthenium Complex for Cancer Phototherapy. Angew Chem Int Ed Engl 2023. [DOI: 10.1002/ange.202218768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Affiliation(s)
- Guangli He
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Maomao He
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Ran Wang
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Xuezhao Li
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Hanze Hu
- Department of Biomedical Engineering Columbia University New York NY 10027 USA
| | - Dongsheng Wang
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu 610054 China
| | - Ziqian Wang
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Yang Lu
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Ning Xu
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Jianjun Du
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
- Ningbo Institute of Dalian University of Technology 26 Yucai Road, Jiangbei District Ningbo 315016 China
| | - Jiangli Fan
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
- Ningbo Institute of Dalian University of Technology 26 Yucai Road, Jiangbei District Ningbo 315016 China
| | - Xiaojun Peng
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
| | - Wen Sun
- State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical Engineering Dalian University of Technology Dalian 116024 China
- Ningbo Institute of Dalian University of Technology 26 Yucai Road, Jiangbei District Ningbo 315016 China
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7
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Oladipupo OE, Prescott MC, Blevins ER, Gray JL, Cameron CG, Qu F, Ward NA, Pierce AL, Collinson ER, Hall JF, Park S, Kim Y, McFarland SA, Fedin I, Papish ET. Ruthenium Complexes with Protic Ligands: Influence of the Position of OH Groups and π Expansion on Luminescence and Photocytotoxicity. Int J Mol Sci 2023; 24:ijms24065980. [PMID: 36983054 PMCID: PMC10053956 DOI: 10.3390/ijms24065980] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Protic ruthenium complexes using the dihydroxybipyridine (dhbp) ligand combined with a spectator ligand (N,N = bpy, phen, dop, Bphen) have been studied for their potential activity vs. cancer cells and their photophysical luminescent properties. These complexes vary in the extent of π expansion and the use of proximal (6,6'-dhbp) or distal (4,4'-dhbp) hydroxy groups. Eight complexes are studied herein as the acidic (OH bearing) form, [(N,N)2Ru(n,n'-dhbp)]Cl2, or as the doubly deprotonated (O- bearing) form. Thus, the presence of these two protonation states gives 16 complexes that have been isolated and studied. Complex 7A, [(dop)2Ru(4,4'-dhbp)]Cl2, has been recently synthesized and characterized spectroscopically and by X-ray crystallography. The deprotonated forms of three complexes are also reported herein for the first time. The other complexes studied have been synthesized previously. Three complexes are light-activated and exhibit photocytotoxicity. The log(Do/w) values of the complexes are used herein to correlate photocytotoxicity with improved cellular uptake. For Ru complexes 1-4 bearing the 6,6'-dhbp ligand, photoluminescence studies (all in deaerated acetonitrile) have revealed that steric strain leads to photodissociation which tends to reduce photoluminescent lifetimes and quantum yields in both protonation states. For Ru complexes 5-8 bearing the 4,4'-dhbp ligand, the deprotonated Ru complexes (5B-8B) have low photoluminescent lifetimes and quantum yields due to quenching that is proposed to involve the 3LLCT excited state and charge transfer from the [O2-bpy]2- ligand to the N,N spectator ligand. The protonated OH bearing 4,4'-dhbp Ru complexes (5A-8A) have long luminescence lifetimes which increase with increasing π expansion on the N,N spectator ligand. The Bphen complex, 8A, has the longest lifetime of the series at 3.45 μs and a photoluminescence quantum yield of 18.7%. This Ru complex also exhibits the best photocytotoxicity of the series. A long luminescence lifetime is correlated with greater singlet oxygen quantum yields because the triplet excited state is presumably long-lived enough to interact with 3O2 to yield 1O2.
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Affiliation(s)
- Olaitan E Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Meredith C Prescott
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Emily R Blevins
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Jessica L Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nicholas A Ward
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Abigail L Pierce
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Elizabeth R Collinson
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - James Fletcher Hall
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Seungjo Park
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Igor Fedin
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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8
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Schüssler L, Israil RGE, Hütchen P, Thiel WR, Diller R, Riehn C. Ultrafast spectroscopy of Ru II polypyridine complexes in the gas phase and the liquid phase: [Ru(2,2'-bipyridine) 2(nicotinamide) 2] 2. Phys Chem Chem Phys 2023; 25:4899-4914. [PMID: 36722394 DOI: 10.1039/d2cp03765c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
[Ru(bipyridine)2(nicotinamide)2]2+ (1) and its monoaqua-complex [Ru(bipyridine)2(nicotinamide)(H2O)]2+ (2) were spectroscopically studied for the first time in the gas phase by static and time resolved UV photodissociation spectroscopy, observing nicotinamide and H2O ligand dissociation for 1 and 2, respectively. Both processes and their ultrafast dynamics were investigated in parallel by transient absorption spectroscopy in aqueous solution. The latter data were newly acquired for the long-wavelength MLCT band excitation of 1 and provide novel ultrafast ligand dissociation results for 2, confirming the gas phase results, i.e., exclusive H2O cleavage over nicotinamide loss. Similar apparent time constants in the sub-ps and few ps ranges were obtained for 1 in both phases, whereas a larger time constant of ca. two hundreds of ps for the ground state recovery was observed exclusively in the solution phase. Our reaction scheme accounts for faster dissociation dynamics in the gas phase by energetical lowering of the 3MC vs. the 3MLCT states by lack of solvent stabilization of the latter. Based on the apparent time constants, we favour, for the solution dynamics, a fast bimodal vibrational deactivation in the 3MLCT/3MC manifolds and a slow dissociation obfuscated by the ground state recovery. This is substantiated by a similar reaction scheme proposed for the ultrafast dynamics of 2, resulting in a new assignment for transient absorption features with λ > 550 nm to the 3MC manifold, and a common kinetic description for 1 and 2. Computations at the TD-DFT/cc-PVTZ/MDF28 level support our spectroscopic findings and the suggested deactivation pathways.
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Affiliation(s)
- L Schüssler
- Department of Physics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 46, D-67663 Kaiserslautern, Germany.
| | - R G E Israil
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 52, D-67663 Kaiserslautern, Germany.
| | - P Hütchen
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 54, D-67663 Kaiserslautern, Germany
| | - W R Thiel
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 54, D-67663 Kaiserslautern, Germany
| | - R Diller
- Department of Physics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 46, D-67663 Kaiserslautern, Germany.
| | - C Riehn
- Department of Chemistry, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 52, D-67663 Kaiserslautern, Germany. .,Research Center OPTIMAS, Erwin-Schrödinger Str. 46, D-67663 Kaiserslautern, Germany
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9
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Turner EE, Breen DJ, Kosgei G, Crandall LA, Curtin GM, Jakubikova E, O’Donnell RM, Ziegler CJ, Rack JJ. Manipulating Excited State Properties of Iridium Phenylpyridine Complexes with “Push–Pull” Substituents. Inorg Chem 2022; 61:18842-18849. [DOI: 10.1021/acs.inorgchem.2c02269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Emigdio E. Turner
- Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Douglas J. Breen
- Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Gilbert Kosgei
- Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Laura A. Crandall
- Department of Chemistry, University of Akron, Akron, Ohio 44325-3601, United States
| | - Gregory M. Curtin
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Ryan M. O’Donnell
- DEVCOM Army Research Laboratory, Adelphi, Maryland 20783, United States
| | | | - Jeffrey J. Rack
- Department of Chemistry and Chemical Biology, The University of New Mexico, Albuquerque, New Mexico 87131, United States
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10
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Steinke SJ, Piechota EJ, Loftus LM, Turro C. Acetonitrile Ligand Photosubstitution in Ru(II) Complexes Directly from the 3MLCT State. J Am Chem Soc 2022; 144:20177-20182. [DOI: 10.1021/jacs.2c07209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sean J. Steinke
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States
| | - Eric J. Piechota
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States
| | - Lauren M. Loftus
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States
| | - Claudia Turro
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States
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11
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Chen Q, Cuello-Garibo JA, Bretin L, Zhang L, Ramu V, Aydar Y, Batsiun Y, Bronkhorst S, Husiev Y, Beztsinna N, Chen L, Zhou XQ, Schmidt C, Ott I, Jager MJ, Brouwer AM, Snaar-Jagalska BE, Bonnet S. Photosubstitution in a trisheteroleptic ruthenium complex inhibits conjunctival melanoma growth in a zebrafish orthotopic xenograft model. Chem Sci 2022; 13:6899-6919. [PMID: 35774173 PMCID: PMC9200134 DOI: 10.1039/d2sc01646j] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/13/2022] [Indexed: 12/28/2022] Open
Abstract
In vivo data are rare but essential for establishing the clinical potential of ruthenium-based photoactivated chemotherapy (PACT) compounds, a new family of phototherapeutic drugs that are activated via ligand photosubstitution. Here a novel trisheteroleptic ruthenium complex [Ru(dpp)(bpy)(mtmp)](PF6)2 ([2](PF6)2, dpp = 4,7-diphenyl-1,10-phenanthroline, bpy = 2,2′-bipyridine, mtmp = 2-methylthiomethylpyridine) was synthesized and its light-activated anticancer properties were validated in cancer cell monolayers, 3D tumor spheroids, and in embryonic zebrafish cancer models. Upon green light irradiation, the non-toxic mtmp ligand is selectively cleaved off, thereby releasing a phototoxic ruthenium-based photoproduct capable notably of binding to nuclear DNA and triggering DNA damage and apoptosis within 24–48 h. In vitro, fifteen minutes of green light irradiation (21 mW cm−2, 19 J cm−2, 520 nm) were sufficient to generate high phototherapeutic indexes (PI) for this compound in a range of cancer cell lines including lung (A549), prostate (PC3Pro4), conjunctival melanoma (CRMM1, CRMM2, CM2005.1) and uveal melanoma (OMM1, OMM2.5, Mel270) cancer cell lines. The therapeutic potential of [2](PF6)2 was further evaluated in zebrafish embryo ectopic (PC3Pro4) or orthotopic (CRMM1, CRMM2) tumour models. The ectopic model consisted of red fluorescent PC3Pro4-mCherry cells injected intravenously (IV) into zebrafish, that formed perivascular metastatic lesions at the posterior ventral end of caudal hematopoietic tissue (CHT). By contrast, in the orthotopic model, CRMM1- and CRMM2-mCherry cells were injected behind the eye where they developed primary lesions. The maximally-tolerated dose (MTD) of [2](PF6)2 was first determined for three different modes of compound administration: (i) incubating the fish in prodrug-containing water (WA); (ii) injecting the prodrug intravenously (IV) into the fish; or (iii) injecting the prodrug retro-orbitally (RO) into the fish. To test the anticancer efficiency of [2](PF6)2, the embryos were treated 24 h after engraftment at the MTD. Optimally, four consecutive PACT treatments were performed on engrafted embryos using 60 min drug-to-light intervals and 90 min green light irradiation (21 mW cm−2, 114 J cm−2, 520 nm). Most importantly, this PACT protocol was not toxic to the zebrafish. In the ectopic prostate tumour models, where [2](PF6)2 showed the highest photoindex in vitro (PI > 31), the PACT treatment did not significantly diminish the growth of primary lesions, while in both conjunctival melanoma orthotopic tumour models, where [2](PF6)2 showed more modest photoindexes (PI ∼ 9), retro-orbitally administered PACT treatment significantly inhibited growth of the engrafted tumors. Overall, this study represents the first demonstration in zebrafish cancer models of the clinical potential of ruthenium-based PACT, here against conjunctival melanoma. A new tris-heteroleptic photoactivated chemotherapy ruthenium complex induces apoptosis upon green light activation in a zebrafish orthothopic conjunctival melanoma xenograft model.![]()
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Affiliation(s)
- Quanchi Chen
- Division of Spine Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School Nanjing China.,Institute of Biology, Leiden University Leiden The Netherlands +31-71-527-4980
| | - Jordi-Amat Cuello-Garibo
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Ludovic Bretin
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Liyan Zhang
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Vadde Ramu
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Yasmin Aydar
- Institute of Biology, Leiden University Leiden The Netherlands +31-71-527-4980
| | - Yevhen Batsiun
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Sharon Bronkhorst
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Yurii Husiev
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Nataliia Beztsinna
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Lanpeng Chen
- Institute of Biology, Leiden University Leiden The Netherlands +31-71-527-4980
| | - Xue-Quan Zhou
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
| | - Claudia Schmidt
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig Beethovenstrasse 55 D-38106 Braunschweig Germany
| | - Ingo Ott
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig Beethovenstrasse 55 D-38106 Braunschweig Germany
| | - Martine J Jager
- Department of Ophthalmology, Leiden University Medical Center Leiden The Netherlands
| | - Albert M Brouwer
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands
| | | | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University P. O. Box 9502 2300 RA Leiden The Netherlands +31-71-527-4260
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12
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Margaret McCutcheon M, Freindorf M, Kraka E. Bonding in Nitrile Photo-dissociating Ruthenium Drug Candidates --A Local Vibrational Mode Study. J Chem Phys 2022; 157:014301. [DOI: 10.1063/5.0094567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we investigated bonding features 15 ruthenium complexes of the type [Ru(tpy)(L)-(CH3CN)]n+, containing the tridentate tpy ligand (tpy = 2,2':6',2'--terpyridine) and various bidentate ancillary ligands, 12 compounds originally synthesized by Loftus et al. (J. Phys. Chem. C 123, 10291-10299 (2019)) complemented with three additional complexes. The main focus of our work was to relate these local features to the experimental data of Loftus et al. which assess the efficiency of nitrile release in an indirect way via observed quantum yields for ruthenium water association after nitrile release. As a tool to quantitatively assess Ru-NC and Ru-L bonding we utilized the local vibrational mode analysis complemented by the topological analysis of the electron density and the natural bond orbital analysis. Interestingly, the stronger Ru-NC bonds have the greater observed quantum yields, leading to the conclusion that the observed quantum yields are a result of a complex interplay of several processes excluding a direct relationship between QY and Ru-NC or Ru-L bond strengths. We identified the ST splitting as one of the key players and not the Ru-NC bond strength, as one may have thought. In summary, this work has presented a modern computational tool set for the investigation of bonding features applied to nitrile photo-dissociating ruthenium drug candidates forming a valuable basis for future design and fine tuning of nitrile releasing ruthenium compounds, as well as for the understanding of how local properties affect overall experimental outcomes.
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Affiliation(s)
| | | | - Elfi Kraka
- Chemistry, Southern Methodist University, United States of America
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13
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Papish ET, Oladipupo OE. Factors that influence singlet oxygen formation vs. ligand substitution for light-activated ruthenium anticancer compounds. Curr Opin Chem Biol 2022; 68:102143. [PMID: 35483128 DOI: 10.1016/j.cbpa.2022.102143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/06/2022] [Accepted: 03/08/2022] [Indexed: 11/03/2022]
Abstract
This review focuses on light-activated ruthenium anticancer compounds and the factors that influence which pathway is favored. Photodynamic therapy (PDT) is favored by π expansion and the presence of low-lying triplet excited states (e.g. 3MLCT, 3IL). Photoactivated chemotherapy (PACT) refers to light-driven ligand dissociation to give a toxic metal complex or a toxic ligand upon photo substitution. This process is driven by steric bulk near the metal center and weak metal-ligand bonds to create a low-energy 3MC state with antibonding character. With protic dihydroxybipyridine ligands, ligand charge can play a key role in these processes, with a more electron-rich deprotonated ligand favoring PDT and an electron-poor protonated ligand favoring PACT in several cases.
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Affiliation(s)
- Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.
| | - Olaitan E Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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14
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Oladipupo O, Brown SR, Lamb RW, Gray JL, Cameron CG, DeRegnaucourt AR, Ward NA, Hall JF, Xu Y, Petersen CM, Qu F, Shrestha AB, Thompson MK, Bonizzoni M, Webster CE, McFarland SA, Kim Y, Papish ET. Light-responsive and Protic Ruthenium Compounds Bearing Bathophenanthroline and Dihydroxybipyridine Ligands Achieve Nanomolar Toxicity towards Breast Cancer Cells. Photochem Photobiol 2022; 98:102-116. [PMID: 34411308 PMCID: PMC8810589 DOI: 10.1111/php.13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/16/2021] [Indexed: 01/03/2023]
Abstract
We report new ruthenium complexes bearing the lipophilic bathophenanthroline (BPhen) ligand and dihydroxybipyridine (dhbp) ligands which differ in the placement of the OH groups ([(BPhen)2 Ru(n,n'-dhbp)]Cl2 with n = 6 and 4 in 1A and 2A , respectively). Full characterization data are reported for 1A and 2A and single crystal X-ray diffraction for 1A . Both 1A and 2A are diprotic acids. We have studied 1A , 1B , 2A , and 2B (B = deprotonated forms) by UV-vis spectroscopy and 1 photodissociates, but 2 is light stable. Luminescence studies reveal that the basic forms have lower energy 3 MLCT states relative to the acidic forms. Complexes 1A and 2A produce singlet oxygen with quantum yields of 0.05 and 0.68, respectively, in acetonitrile. Complexes 1 and 2 are both photocytotoxic toward breast cancer cells, with complex 2 showing EC50 light values as low as 0.50 μM with PI values as high as >200 vs. MCF7. Computational studies were used to predict the energies of the 3 MLCT and 3 MC states. An inaccessible 3 MC state for 2B suggests a rationale for why photodissociation does not occur with the 4,4'-dhbp ligand. Low dark toxicity combined with an accessible 3 MLCT state for 1 O2 generation explains the excellent photocytotoxicity of 2.
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Affiliation(s)
- Olaitan Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Spenser R. Brown
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Robert W. Lamb
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Jessica L. Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA
| | - Alexa R. DeRegnaucourt
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nicholas A. Ward
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - James Fletcher Hall
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Yifei Xu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Courtney M. Petersen
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Ambar B. Shrestha
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Matthew K. Thompson
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Elizabeth T. Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
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15
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Toupin NP, Steinke SJ, Herroon MK, Podgorski I, Turro C, Kodanko JJ. Unlocking the Potential of Ru(II) Dual-action Compounds with the Power of the Heavy-atom Effect. Photochem Photobiol 2021; 98:378-388. [PMID: 34866185 DOI: 10.1111/php.13573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/29/2022]
Abstract
We report the synthesis, photochemical and biological characterization of two new Ru(II) photoactivated complexes based on [Ru(tpy)(Me2 bpy)(L)]2+ (tpy = 2,2':6',2''-terpyridine, Me2 bpy = 6,6'-dimethyl-2,2'-bipyridine), where L = pyridyl-BODIPY (pyBOD). Two pyBOD ligands were prepared bearing flanking hydrogen or iodine atoms. Ru(II)-bound BODIPY dyes show a red-shift of absorption maxima relative to the free dyes and undergo photodissociation of BODIPY ligands with green light irradiation. Addition of iodine into the BODIPY ligand facilitates intersystem crossing, which leads to efficient singlet oxygen production in the free dye, but also enhances quantum yield of release of the BODIPY ligand from Ru(II). This represents the first report of a strategy to enhance photodissociation quantum yields through the heavy-atom effect in Ru(II) complexes. Furthermore, Ru(II)-bound BODIPY dyes display fluorescence turn-on once released, with a lead analog showing nanomolar EC50 values against triple negative breast cancer cells, >100-fold phototherapeutic indexes under green light irradiation, and higher selectivity toward cancer cells as compared to normal cells than the corresponding free BODIPY photosensitizer. Conventional Ru(II) photoactivated complexes require nonbiorthogonal blue light for activation and rarely show submicromolar potency to achieve cell death. Our study represents an avenue for the improved photochemistry and potency of future Ru(II) complexes.
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Affiliation(s)
| | - Sean J Steinke
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH
| | - Mackenzie K Herroon
- Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI
| | - Izabela Podgorski
- Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI
| | - Claudia Turro
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH
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16
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Awada A, Loiseau F, Jouvenot D. Light‐Induced Ejection of a Tridentate Ligand from a Ruthenium(II) Complex. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ali Awada
- Département de Chimie Moléculaire Univ. Grenoble Alpes, CNRS, DCM 38000 Grenoble France
| | - Frédérique Loiseau
- Département de Chimie Moléculaire Univ. Grenoble Alpes, CNRS, DCM 38000 Grenoble France
| | - Damien Jouvenot
- Département de Chimie Moléculaire Univ. Grenoble Alpes, CNRS, DCM 38000 Grenoble France
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17
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Lanquist AP, Gupta S, Al-Afyouni KF, Al-Afyouni M, Kodanko JJ, Turro C. Trifluoromethyl substitution enhances photoinduced activity against breast cancer cells but reduces ligand exchange in Ru(ii) complex. Chem Sci 2021; 12:12056-12067. [PMID: 34667571 PMCID: PMC8457392 DOI: 10.1039/d1sc03213e] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 08/09/2021] [Indexed: 12/15/2022] Open
Abstract
A series of five ruthenium complexes containing triphenyl phosphine groups known to enhance both cellular penetration and photoinduced ligand exchange, cis-[Ru(bpy)2(P(p-R-Ph)3)(CH3CN)]2+, where bpy = 2,2'-bipyridine and P(p-R-Ph)3 represent para-substituted triphenylphosphine ligands with R = -OCH3 (1), -CH3 (2) -H (3), -F (4), and -CF3 (5), were synthesized and characterized. The photolysis of 1-5 in water with visible light (λ irr ≥ 395 nm) results in the substitution of the coordinated acetonitrile with a solvent molecule, generating the corresponding aqua complex as the single photoproduct. A 3-fold variation in quantum yield was measured with 400 nm irradiation, Φ 400, where 1 is the most efficient with a Φ 400 = 0.076(2), and 5 the least photoactive complex, with Φ 400 = 0.026(2). This trend is unexpected based on the red-shifted metal-to-ligand charge transfer (MLCT) absorption of 1 as compared to that of 5, but can be correlated to the substituent Hammett para parameters and pK a values of the ancillary phosphine ligands. Complexes 1-5 are not toxic towards the triple negative breast cancer cell line MDA-MB-231 in the dark, but 3 and 5 are >4.2 and >19-fold more cytotoxic upon irradiation with blue light, respectively. A number of experiments point to apoptosis, and not to necrosis or necroptosis, as the mechanism of cell death by 5 upon irradiation. These findings provide a foundation for understanding the role of phosphine ligands on photoinduced ligand substitution and show the enhancement afforded by -CF3 groups on photochemotherapy, which will aid the future design of photocages for photochemotherapeutic drug delivery.
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Affiliation(s)
- Austin P Lanquist
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Sayak Gupta
- Department of Chemistry, Wayne State University Detroit MI 48208 USA
| | - Kathlyn F Al-Afyouni
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Malik Al-Afyouni
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
| | - Jeremy J Kodanko
- Department of Chemistry, Wayne State University Detroit MI 48208 USA
| | - Claudia Turro
- Department of Chemistry and Biochemistry, The Ohio State University Columbus OH 43210 USA
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18
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Busemann A, Flaspohler I, Zhou XQ, Schmidt C, Goetzfried SK, van Rixel VHS, Ott I, Siegler MA, Bonnet S. Ruthenium-based PACT agents based on bisquinoline chelates: synthesis, photochemistry, and cytotoxicity. J Biol Inorg Chem 2021; 26:667-674. [PMID: 34378103 PMCID: PMC8437835 DOI: 10.1007/s00775-021-01882-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/12/2021] [Indexed: 12/14/2022]
Abstract
The known ruthenium complex [Ru(tpy)(bpy)(Hmte)](PF6)2 ([1](PF6)2, where tpy = 2,2':6',2″-terpyridine, bpy = 2,2'-bipyridine, Hmte = 2-(methylthio)ethanol) is photosubstitutionally active but non-toxic to cancer cells even upon light irradiation. In this work, the two analogs complexes [Ru(tpy)(NN)(Hmte)](PF6)2, where NN = 3,3'-biisoquinoline (i-biq, [2](PF6)2) and di(isoquinolin-3-yl)amine (i-Hdiqa, [3](PF6)2), were synthesized and their photochemistry and phototoxicity evaluated to assess their suitability as photoactivated chemotherapy (PACT) agents. The increase of the aromatic surface of [2](PF6)2 and [3](PF6)2, compared to [1](PF6)2, leads to higher lipophilicity and higher cellular uptake for the former complexes. Such improved uptake is directly correlated to the cytotoxicity of these compounds in the dark: while [2](PF6)2 and [3](PF6)2 showed low EC50 values in human cancer cells, [1](PF6)2 is not cytotoxic due to poor cellular uptake. While stable in the dark, all complexes substituted the protecting thioether ligand upon light irradiation (520 nm), with the highest photosubstitution quantum yield found for [3](PF6)2 (Φ[3] = 0.070). Compounds [2](PF6)2 and [3](PF6)2 were found both more cytotoxic after light activation than in the dark, with a photo index of 4. Considering the very low singlet oxygen quantum yields of these compounds, and the lack of cytotoxicity of the photoreleased Hmte thioether ligand, it can be concluded that the toxicity observed after light activation is due to the photoreleased aqua complexes [Ru(tpy)(NN)(OH2)]2+, and thus that [2](PF6)2 and [3](PF6)2 are promising PACT candidates.
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Affiliation(s)
- Anja Busemann
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Ingrid Flaspohler
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Xue-Quan Zhou
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Claudia Schmidt
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstrasse 55, 38106, Braunschweig, Germany
| | - Sina K Goetzfried
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Vincent H S van Rixel
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands
| | - Ingo Ott
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Beethovenstrasse 55, 38106, Braunschweig, Germany
| | - Maxime A Siegler
- Small Molecule X-Ray Facility, Department of Chemistry, Johns Hopkins University, Baltimore, Maryland, 21218, USA
| | - Sylvestre Bonnet
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC, Leiden, The Netherlands.
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19
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Qu F, Lamb RW, Cameron CG, Park S, Oladipupo O, Gray JL, Xu Y, Cole HD, Bonizzoni M, Kim Y, McFarland SA, Webster CE, Papish ET. Singlet Oxygen Formation vs Photodissociation for Light-Responsive Protic Ruthenium Anticancer Compounds: The Oxygenated Substituent Determines Which Pathway Dominates. Inorg Chem 2021; 60:2138-2148. [PMID: 33534562 DOI: 10.1021/acs.inorgchem.0c02027] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ruthenium complexes bearing protic diimine ligands are cytotoxic to certain cancer cells upon irradiation with blue light. Previously reported complexes of the type [(N,N)2Ru(6,6'-dhbp)]Cl2 with 6,6'-dhbp = 6,6'-dihydroxybipyridine and N,N = 2,2'-bipyridine (bipy) (1A), 1,10-phenanthroline (phen) (2A), and 2,3-dihydro-[1,4]dioxino[2,3-f][1,10]phenanthroline (dop) (3A) show EC50 values as low as 4 μM (for 3A) vs breast cancer cells upon blue light irradiation ( Inorg. Chem. 2017, 56, 7519). Herein, subscript A denotes the acidic form of the complex bearing OH groups, and B denotes the basic form bearing O- groups. This photocytotoxicity was originally attributed to photodissociation, but recent results suggest that singlet oxygen formation is a more plausible cause of photocytotoxicity. In particular, bulky methoxy substituents enhance photodissociation but these complexes are nontoxic ( Dalton Trans 2018, 47, 15685). Cellular studies are presented herein that show the formation of reactive oxygen species (ROS) and apoptosis indicators upon treatment of cells with complex 3A and blue light. Singlet oxygen sensor green (SOSG) shows the formation of 1O2 in cell culture for cells treated with 3A and blue light. At physiological pH, complexes 1A-3A are deprotonated to form 1B-3B in situ. Quantum yields for 1O2 (ϕΔ) are 0.87 and 0.48 for 2B and 3B, respectively, and these are an order of magnitude higher than the quantum yields for 2A and 3A. The values for ϕΔ show an increase with 6,6'-dhbp derived substituents as follows: OMe < OH < O-. TD-DFT studies show that the presence of a low lying triplet metal-centered (3MC) state favors photodissociation and disfavors 1O2 formation for 2A and 3A (OH groups). However, upon deprotonation (O- groups), the 3MLCT state is accessible and can readily lead to 1O2 formation, but the dissociative 3MC state is energetically inaccessible. The changes to the energy of the 3MLCT state upon deprotonation have been confirmed by steady state luminescence experiments on 1A-3A and their basic analogs, 1B-3B. This energy landscape favors 1O2 formation for 2B and 3B and leads to enhanced toxicity for these complexes under physiological conditions. The ability to convert readily from OH to O- groups allowed us to investigate an electronic change that is not accompanied by steric changes in this fundamental study.
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Affiliation(s)
- Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Robert W Lamb
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Seungjo Park
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Olaitan Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Jessica L Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Yifei Xu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Houston D Cole
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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20
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Abstract
More than four decades have passed since the first example of a light-activated (caged) compound was described. In the intervening years, a large number of light-responsive derivatives have been reported, several of which have found utility under a variety of in vitro conditions using cells and tissues. Light-triggered bioactivity furnishes spatial and temporal control, and offers the possibility of precision dosing and orthogonal communication with different biomolecules. These inherent attributes of light have been advocated as advantageous for the delivery and/or activation of drugs at diseased sites for a variety of indications. However, the tissue penetrance of light is profoundly wavelength-dependent. Only recently have phototherapeutics that are photoresponsive in the optical window of tissue (600-900 nm) been described. This Review highlights these recent discoveries, along with their limitations and clinical opportunities. In addition, we describe preliminary in vivo studies of prospective phototherapeutics, with an emphasis on the path that remains to be navigated in order to translate light-activated drugs into clinically useful therapeutics. Finally, the unique attributes of phototherapeutics is highlighted by discussing several potential disease applications.
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Ryan RT, Havrylyuk D, Stevens KC, Moore LH, Kim DY, Blackburn JS, Heidary DK, Selegue JP, Glazer EC. Avobenzone incorporation in a diverse range of Ru(II) scaffolds produces potent potential antineoplastic agents. Dalton Trans 2020; 49:12161-12167. [PMID: 32845256 PMCID: PMC8607750 DOI: 10.1039/d0dt02016h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Four structurally distinct classes of polypyridyl ruthenium complexes containing avobenzone exhibited low micromolar and submicromolar potencies in cancer cells, and were up to 273-fold more active than the parent ligand. Visible light irradiation enhanced the cytotoxicity of some complexes, making them promising candidates for combined chemo-photodynamic therapy.
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Affiliation(s)
- Raphael T Ryan
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, KY 40506, USA.
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22
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Soupart A, Alary F, Heully JL, Elliott PIP, Dixon IM. Theoretical Study of the Full Photosolvolysis Mechanism of [Ru(bpy)3]2+: Providing a General Mechanistic Roadmap for the Photochemistry of [Ru(N^N)3]2+-Type Complexes toward Both Cis and Trans Photoproducts. Inorg Chem 2020; 59:14679-14695. [DOI: 10.1021/acs.inorgchem.0c01843] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Adrien Soupart
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Fabienne Alary
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Jean-Louis Heully
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
| | - Paul I. P. Elliott
- Department of Chemistry and Centre for Functional Materials, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Isabelle M. Dixon
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, 118 route de Narbonne, 31062 Toulouse, France
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23
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Hirahara M, Nakano H, Uchida K, Yamamoto R, Umemura Y. Intramolecular Hydrogen Bonding: A Key Factor Controlling the Photosubstitution of Ruthenium Complexes. Inorg Chem 2020; 59:11273-11286. [PMID: 32799483 DOI: 10.1021/acs.inorgchem.0c00738] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Photosubstitution reactions of ruthenium complexes with pyrazole ligands, cis-[Ru(bpy)2(pzH)2]2+ (1a), cis-[Ru(bpy)2(pz)(pzH)]+ (1b), and cis-[Ru(bpy)2(pz)2]0 (1c) (pzH = pyrazole, bpy = 2,2'-bipyridine), were investigated. Dicationic complex 1a was deprotonated to 1b using moderate base (pKa = 15.2, MeCN), while the second deprotonation to give 1c required more severe conditions (pKa = 26.9). Monocationic complex 1b possessed an N-H···N-type intramolecular hydrogen bond between the pyrazole and pyrazolate ligands, as corroborated by the solid-state crystal structure. The photosubstitution quantum yield of 1a (Φ = 0.26) was comparable to that of cis-[Ru(bpy)2(pyridine)2]2+ (Φ = 0.24) in acetonitrile solution. In contrast, the photodissociation of a pzH ligand was strongly suppressed by the deprotonation of a pyrazole ligand N-H group. In the presence of 10 000 equiv of 4,4'-dimethylaminopyridine, the quantum yield dropped to ∼2 × 10-6 in acetonitrile. The photosubstitution quantum yield of 1b was even smaller than that of neutral complex 1c, although 1c had a smaller HOMO-LUMO energy gap than monocationic complex 1b. The small quantum yield of 1b was attributed to intramolecular hydrogen bonding between pyrazole and pyrazolate ligands. The apparent rate constants for the photosubstitution of 1b were highly solvent-dependent. The photosubstitution of 1b was suppressed in aprotic solvents, while the reaction was accelerated by 2 orders of magnitude in protic solvents with strong proton donor abilities.
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Affiliation(s)
- Masanari Hirahara
- Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan
| | - Hiroyuki Nakano
- Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan
| | - Kyohei Uchida
- Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan
| | - Rei Yamamoto
- Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan
| | - Yasushi Umemura
- Department of Applied Chemistry, School of Applied Science, National Defense Academy of Japan, Hashirimizu 1-10-20, Yokosuka, Kanagawa 239-8686, Japan
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