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Kokkosi A, Garofallidou E, Zacharopoulos N, Tsoureas N, Diamanti K, Thomaidis NS, Cheilari A, Machalia C, Emmanouilidou E, Philippopoulos AI. Ruthenium p-Cymene Complexes Incorporating Substituted Pyridine-Quinoline-Based Ligands: Synthesis, Characterization, and Cytotoxic Properties. Molecules 2024; 29:3215. [PMID: 38999167 PMCID: PMC11243419 DOI: 10.3390/molecules29133215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
Organometallic complexes of the formula [Ru(N^N)(p-cymene)Cl][X] (N^N = bidentate polypyridyl ligands, p-cymene = 1-methyl-4-(1-methylethyl)-benzene, X = counter anion), are currently studied as possible candidates for the potential treatment of cancer. Searching for new organometallic compounds with good to moderate cytotoxic activities, a series of mononuclear water-soluble ruthenium(II)-arene complexes incorporating substituted pyridine-quinoline ligands, with pending -CH2OH, -CO2H and -CO2Me groups in the 4-position of quinoline ring, were synthesized, for the first time, to study their possible effect to modulate the activity of the ruthenium p-cymene complexes. These include the [Ru(η6-p-cymene)(pqhyme)Cl][X] (X = Cl- (1-Cl), PF6- (1-PF6), pqhyme = 4-hydroxymethyl-2-(pyridin-2-yl)quinoline), [Ru(η6-p-cymene)(pqca)Cl][Cl] ((2-Cl), pqca = 4-carboxy-2-(pyridin-2-yl)quinoline), and [Ru(η6-p-cymene)(pqcame)Cl][X] (X = Cl- (3-Cl), PF6- (3-PF6), pqcame = 4-carboxymethyl-2-(pyridin-2-yl)quinoline) complexes, respectively. Identification of the complexes was based on multinuclear NMR and ATR-IR spectroscopic methods, elemental analysis, conductivity measurements, UV-Vis spectroscopic, and ESI-HRMS techniques. The solid-state structures of 1-PF6 and 3-PF6 have been elucidated by single-crystal X-ray diffraction revealing a three-legged piano stool geometry. This is the first time that the in vitro cytotoxic activities of these complexes are studied. These were conducted in HEK293T (human embryonic kidney cells) and HeLa cells (cervical cancer cells) via the MTT assay. The results show poor in vitro anticancer activities for the HeLa cancer cell lines and 3-Cl proved to be the most potent (IC50 > 80 μΜ). In both cell lines, the cytotoxicity of the ligand precursor pqhyme is significantly higher than that of cisplatin.
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Affiliation(s)
- Afroditi Kokkosi
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Elpida Garofallidou
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Nikolaos Zacharopoulos
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Nikolaos Tsoureas
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Konstantina Diamanti
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Nikolaos S Thomaidis
- Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Antigoni Cheilari
- Department of Pharmacognosy and Natural Products Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Christina Machalia
- Laboratory of Biochemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Evangelia Emmanouilidou
- Laboratory of Biochemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Athanassios I Philippopoulos
- Laboratory of Inorganic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
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2
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Sarıdağ T, Buldurun K. New Ruthenium-p-Cymene Complexes Containing o-Vanillin and 4-Benzoxybenzaldehyde Schiff Base Ligands; Synthesis, Characterization and Catalytic Activity in the Transfer Hydrogenation of Ketones. Catal Letters 2023. [DOI: 10.1007/s10562-023-04286-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Kilincarslan SD, Sahin C, Mutlu D, Nasirli F, Arslan S, Dogan NM. Synthesis, Characterization, Antibiofilm and Anticancer Activity of New Ruthenium Complexes with 2,2'-Bipyridine-4,4'-Dicarboxamide. LETT ORG CHEM 2022. [DOI: 10.2174/1570178619666220329164106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
New ruthenium complexes bearing bipyridine ligands with different substituents (propyl, hexyl, isobutyl, and benzyl) were synthesized and characterized by MS, NMR, FTIR, and UV/Visible spectroscopy. Moreover, their cytotoxic, anti-carcinogenic, and anti-biofilm activities were evaluated. The electrochemical properties of the complexes have been investigated by cyclic voltammetry. The HOMO and LUMO energy levels of RuL1-RuL4 were found as (-5.45 eV)-(-5.46 eV) and (-2.98 eV)-(-3.01 eV), respectively. Cytotoxic activities of ruthenium complexes were investigated in Caco-2, HepG2, and HEK293 cells. It was found that RuL3 showed a cytotoxic effect on cancer cells without affecting non-cancerous cells at applied doses. The presence of the benzyl group may increase the cytotoxic effect of RuL3 compared to other derivatives that contain the alkyl group. The apoptotic effect of the RuL3 derivative was determined by using Arthur image-based cytometer. It found that RuL3 was induced apoptosis in Caco-2 (5-fold) and HepG2 (2-fold) cancer cells, respectively. All ruthenium complexes inhibited Staphylococcus aureus ATCC 29213 biofilm, but RuL3 had a more pronounced effect. Moreover, RuL3 had biofilm inhibition and biofilm degradation effect while RuL1 and RuL4 demonstrated only biofilm inhibition. The fluorescent microscopy analysis confirmed the antibiofilm effect of ruthenium complexes. All of these results clearly showed that RuL3 showed cytotoxic and apoptotic effects on cancer cells.
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Affiliation(s)
| | - Cigdem Sahin
- Department of Chemistry, Art&Science Faculty, Pamukkale University, Denizli, Turkey
| | - Dogukan Mutlu
- Department of Biology, Art&Science Faculty, Pamukkale University, Denizli, Turkey
| | - Farid Nasirli
- Department of Biology, Art&Science Faculty, Pamukkale University, Denizli, Turkey
| | - Sevki Arslan
- Department of Biology, Art&Science Faculty, Pamukkale University, Denizli, Turkey
| | - Nazime Mercan Dogan
- Department of Biology, Art&Science Faculty, Pamukkale University, Denizli, Turkey
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4
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Schnierle M, Leimkühler M, Ringenberg MR. [(η 6- p-Cymene)[3-(pyrid-2-yl)-1,2,4,5-tetrazine]chlororuthenium(II)] +, Redox Noninnocence and Dienophile Addition to Coordinated Tetrazine. Inorg Chem 2021; 60:6367-6374. [PMID: 33856810 DOI: 10.1021/acs.inorgchem.1c00094] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bidentate ligand 3-(pyrid-2-yl)-1,2,4,5-tetrazine (TzPy) coordinated in the complex [CyRuCl(TzPy)]PF6 ([1]+; Cy = η6-p-cymene) shows noninnocent behavior and can be modified through the addition of dienophiles, vinylferrocene (ViFc) or ethynylferrocene (EthFc). The kinetics and transition-state thermodynamic analysis of the reaction of [1]+ + ViFc found ΔG⧧(298 K) = 67 kJ mol-1, while that of [1]+ + EthFc was ΔG⧧(298 K) = 83 kJ mol-1. The room temperature second-order rate of [1]+ + EthFc, k2 = 1.51(4) × 10-2 M-1 s-1, was 3 orders of magnitude faster than that of EthFc + TzPy, k2 = 1.05(15) × 10-4 M-1 s-1. The [1H2Fc]+ complex was converted to [1Fc]+ by oxidation with oxygen and 3,5-di-tert-butyl-o-quinone, and the molecular structure of [1Fc]+ was determined by single-crystal X-ray diffraction. The title complex [1]+ showed a quasi-reversible reduction in the cyclic voltammogram, and the electrochemical reduction mechanism was determined by UV-vis spectroelectrochemistry (SEC) experiments, as well as supported by density functional theory (DFT) calculations. The dihydropyridazine [1H2Fc]+ and pyridazine [1Fc]+ states of the ligand showed ligand noninnocence similar to that of the parent tetrazine but at a cathodically shifted potential. The dihydropyridazine [1H2Fc]+ showed a mixture of several products; however, upon oxidation, only a single product, [1Fc]+, was formed from the endo addition of the dienophile to [1]+. The electrochemical mechanism of [1Fc]+ was also studied by cyclic voltammetry and UV-vis SEC experiments, as well as supported by DFT calculations.
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Affiliation(s)
- Marc Schnierle
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Marie Leimkühler
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Mark R Ringenberg
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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5
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A New Piano-Stool Ruthenium(II) P-Cymene-Based Complex: Crystallographic, Hirshfeld Surface, DFT, and Luminescent Studies. CRYSTALS 2020. [DOI: 10.3390/cryst11010013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A new complex (Ru(η6-p-cymene)(5-ASA)Cl2) (1) where 5-ASA is 5-aminosalicylic acid has been prepared by reacting the ruthenium arene precursors ((η6-arene)Ru(μ-Cl)Cl)2, with the 5-ASA ligands in a 1:1 ratio. Full characterization of complex 1 was accomplished by elemental analysis, IR, and TGA following the structure obtained from a single-crystal X-ray pattern. The structural analysis revealed that complex 1 shows a “piano-stool” geometry with Ru-C (2.160(5)- 2.208(5)Å), Ru-N (2.159(4) Å) distances, which is similar to equivalents sister complex. Density functional theory (DFT) was used to calculate the significant molecular orbital energy levels, binding energies, bond angles, bond lengths, and spectral data (FTIR, NMR, and UV–VIS) of complex 1, consistent with the experimental results. The IR and UV–VIS spectra of complex 1 were computed using all of the methods and choose the most appropriate way to discuss. Hirshfeld surface analysis was also executed to understand the role of weak interactions such as H⋯H, C⋯H, C-H⋯π, and vdW interactions, which play a significant role in the crystal environment’s stability. Moreover, the luminescence results at room temperature show that complex 1 gives a more intense emission band positioned at 465 nm upon excitation at 330 nm makes it a suitable candidate for the building of photoluminescent material.
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Matveevskaya V, Pavlov DI, Sukhikh TS, Gushchin AL, Ivanov AY, Tennikova TB, Sharoyko VV, Baykov SV, Benassi E, Potapov AS. Arene-Ruthenium(II) Complexes Containing 11 H-Indeno[1,2- b]quinoxalin-11-one Derivatives and Tryptanthrin-6-oxime: Synthesis, Characterization, Cytotoxicity, and Catalytic Transfer Hydrogenation of Aryl Ketones. ACS OMEGA 2020; 5:11167-11179. [PMID: 32455240 PMCID: PMC7241045 DOI: 10.1021/acsomega.0c01204] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 04/28/2020] [Indexed: 05/05/2023]
Abstract
A series of novel mono- and binuclear arene-ruthenium(II) complexes [(p-cym)Ru(L)Cl] containing 11H-indeno[1,2-b]quinoxalin-11-one derivatives or tryptanthrin-6-oxime were synthesized and characterized by X-ray crystallography, IR, NMR spectroscopy, cyclic voltammetry, and elemental analysis. Theoretical calculations invoking singlet state geometry optimization, solvation effects, and noncovalent interactions were done using density functional theory (DFT). DFT calculations were also applied to evaluate the electronic properties, and time-dependent DFT was applied to clarify experimental UV-vis results. Cytotoxicity for cancerous and noncancerous human cell lines was evaluated with cell viability MTT assay. Complexes demonstrated a moderate cytotoxic effect toward cancerous human cell line PANC-1. The catalytic activity of the complexes was evaluated in transfer hydrogenation of aryl ketones. All complexes exhibited good catalytic activity and functional group tolerance.
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Affiliation(s)
- Vladislava
V. Matveevskaya
- Kizhner
Research Center, National Research Tomsk
Polytechnic University, 30 Lenin Avenue, 634050 Tomsk, Russia
| | - Dmitry I. Pavlov
- Kizhner
Research Center, National Research Tomsk
Polytechnic University, 30 Lenin Avenue, 634050 Tomsk, Russia
| | - Taisiya S. Sukhikh
- Nikolaev
Institute of Inorganic Chemistry, Siberian
Branch of the Russian Academy of Sciences, 3 Lavrentiev Avenue, 630090 Novosibirsk, Russia
- Department
of Natural Sciences, Novosibirsk State University, 1 Pirogov Street, 630090 Novosibirsk, Russia
| | - Artem L. Gushchin
- Nikolaev
Institute of Inorganic Chemistry, Siberian
Branch of the Russian Academy of Sciences, 3 Lavrentiev Avenue, 630090 Novosibirsk, Russia
- Department
of Natural Sciences, Novosibirsk State University, 1 Pirogov Street, 630090 Novosibirsk, Russia
| | - Alexander Yu. Ivanov
- Center
for Magnetic Resonance, Saint Petersburg
State University, 26
Universitetskii Avenue, 198504 Peterhof, Russia
| | - Tatiana B. Tennikova
- Institute
of Chemistry, Saint Petersburg State University, 26 Universitetskii Avenue, 198504 Peterhof, Russia
| | - Vladimir V. Sharoyko
- Institute
of Chemistry, Saint Petersburg State University, 26 Universitetskii Avenue, 198504 Peterhof, Russia
| | - Sergey V. Baykov
- Institute
of Chemistry, Saint Petersburg State University, 26 Universitetskii Avenue, 198504 Peterhof, Russia
| | - Enrico Benassi
- Department
of Chemistry, Shihezi University, 280N 4th Road, 832000 Shihezi, Xinjiang, PR China
| | - Andrei S. Potapov
- Nikolaev
Institute of Inorganic Chemistry, Siberian
Branch of the Russian Academy of Sciences, 3 Lavrentiev Avenue, 630090 Novosibirsk, Russia
- Department
of Natural Sciences, Novosibirsk State University, 1 Pirogov Street, 630090 Novosibirsk, Russia
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7
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Luminescent anticancer Ru(II)-arenebipyridine and phenanthroline complexes: Synthesis, characterization, DFT studies, biological interactions and cellular imaging application. J Inorg Biochem 2020; 208:111099. [PMID: 32460056 DOI: 10.1016/j.jinorgbio.2020.111099] [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: 03/22/2020] [Revised: 05/02/2020] [Accepted: 05/02/2020] [Indexed: 12/11/2022]
Abstract
A series of ruthenium(II)-arene complexes of several bipyridine and phenanthroline derivatives have been synthesized by employing a green and efficient protocol involving water as a solvent under sonication. The structures of all the complexes were elucidated by the spectroscopic analysis. The geometry of the chlorido and PTA (1,3,5-Triaza-7-phosphaadamantane) complexes were further confirmed by DFT and single crystal XRD. The stability study in various solvents, specifically in the intracellular one was conducted. Most of the compounds exhibited significant potency and selectivity against MCF7 and HeLa cell lines with respect to normal HEK-293 cells compared to cisplatin and RAPTA-C (Ruthenium(II)-arene PTA complex). Complex [(η6-hexamethylbenzene)RuCl(κ2-N,N-4,4'-di-n-nonyl-2,2'-bpy)]Cl (3e) presented best anticancer profiles against all the human cancer cells. Interestingly, few complexes turned up to be highly fluorescent depicted by the quantum yield values. Remarkably, [(η6-p-cymene)RuCl(κ2-N,N-bpy)]Cl (3i) was identified as most significant anticancer theranostic agent interms of potency, selectivity and fluorescence quantum yield. This complex also represented itself as significant cellular imaging agent in live U-87 MG cells which was monitored by confocal microscope. Absorption and emission spectral studies of bypyridine and phenanthroline complex series revealed that the complexes interacted with calf thymus DNA through groove binding as well as intercalative mode. In addition to this, strong binding efficacy of these scaffolds wih BSA (Bovin Serum Albumin) also enhanced their transportation property inside the cells.
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8
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Sarı Y, Gürses C, Celepci DB, Keleştemur Ü, Aktaş A, Yüksel Ş, Ateş B, Gök Y. 4-Vinylbenzyl and 2-morpholinoethyl substituted ruthenium (II) complexes: Design, synthesis, and biological evaluation. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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9
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Backler F, Wilson GJ, Wang F. Rational use of ligand to shift the UV–vis spectrum of Ru-complex sensitiser dyes for DSSC applications. Radiat Phys Chem Oxf Engl 1993 2019. [DOI: 10.1016/j.radphyschem.2019.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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10
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Lenis-Rojas OA, Robalo MP, Tomaz AI, Carvalho A, Fernandes AR, Marques F, Folgueira M, Yáñez J, Vázquez-García D, López Torres M, Fernández A, Fernández JJ. RuII(p-cymene) Compounds as Effective and Selective Anticancer Candidates with No Toxicity in Vivo. Inorg Chem 2018; 57:13150-13166. [DOI: 10.1021/acs.inorgchem.8b01270] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Oscar A. Lenis-Rojas
- Departamento de Química & Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, 15008 A Coruña, Spain
| | - M. Paula Robalo
- Área Departamental de Engenharia Química, ISEL-Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro, 1, 1959-007 Lisboa, Portugal
- Centro de Química Estrutural, Complexo 1, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Ana Isabel Tomaz
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Andreia Carvalho
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
| | - Alexandra R. Fernandes
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
| | - Fernanda Marques
- Centro de Ciências e Tecnologías Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139.7), 2695-066 Bobadela LRS, Portugal
| | - Mónica Folgueira
- Neurover Group, Centro de Investigacións Científicas Avanzadas (CICA) and Department of Biology, Universidade da Coruña, 15008 A Coruña, Spain
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1 6BT, U.K
| | - Julián Yáñez
- Neurover Group, Centro de Investigacións Científicas Avanzadas (CICA) and Department of Biology, Universidade da Coruña, 15008 A Coruña, Spain
| | - Digna Vázquez-García
- Departamento de Química & Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, 15008 A Coruña, Spain
| | - Margarita López Torres
- Departamento de Química & Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, 15008 A Coruña, Spain
| | - Alberto Fernández
- Departamento de Química & Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, 15008 A Coruña, Spain
| | - Jesús J. Fernández
- Departamento de Química & Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, 15008 A Coruña, Spain
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11
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Woodward CP, Rüther T, Coghlan CJ, Jones TW, Hebting Y, Cordiner RL, Dawson RE, Robinson DEJE, Forsyth CM, Wilson GJ. Tetracarboxylate Bis-Bipyridine Ruthenium Dyes: Synthesis, Structural and Electronic Characterisation. Chempluschem 2018; 83:691-703. [PMID: 31950621 DOI: 10.1002/cplu.201800116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/27/2018] [Indexed: 11/08/2022]
Abstract
The preparation of ruthenium complexes with novel 2,2'-bipyridine (bpy) ligands bearing four carboxylic acid groups was investigated with a view to creating dyes containing more than two potential anchoring groups per bpy unit for attachment to a titania surface. Synthetic challenges are encountered upon using the 2,2'-bipyridine-3,3',4,4'-tetracarboxylic acid ligand because it readily decarboxylates. The use of the methyl esterified derivative (3) proved to be more successful for complex preparation, with a robust preparation of the [Ru(3)2 Cl2 ] complex identified with diglyme as the solvent. This complex was further converted into the thiocyanato complex, [Ru(3)2 (NCS)2 ], which could not be completely de-esterified. X-ray analysis of crystals obtained from a mixture of isomers for this complex provided data for the S,S- and N,S-coordinated isomers; both showed a twisted arrangement of the pyridine rings in the 2,2'-bipyridine-3,3',4,4'-tetracarboxylic acid ligand, owing to steric hinderance. Conversely, the isosteric 2,2'-bipyridine-4,4',5,5'-tetracarboxylic acid ligand was easily converted into the desired [Ru(2)2 (NCS)2 ] complex through a standard one-pot procedure in N,N-dimethylformamide solvent. All of the complexes presented herein exhibit a significant redshift for the metal to ligand charge-transfer bands, relative to the benchmark ruthenium dye N719 and derivatives thereof. All complexes exhibit a quasi-reversible process for the ruthenium(II/III) couple at approximately 0.4 V versus the ferrocene couple, comparable to analogous ruthenium dyes.
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Affiliation(s)
| | - Thomas Rüther
- Energy, CSIRO, Research Way, Clayton, VIC, 3168, Australia
| | | | - Timothy W Jones
- Energy, CSIRO, 10 Murray Dwyer Cct, Mayfield West, NSW, 2304, Australia
| | - Yanek Hebting
- Dyesol Australia Pty Ltd, 3 Dominion Place, Queanbeyan, NSW, 2620, Australia
| | - Richard L Cordiner
- Dyesol Australia Pty Ltd, 3 Dominion Place, Queanbeyan, NSW, 2620, Australia
| | - Ryan E Dawson
- Dyesol Australia Pty Ltd, 3 Dominion Place, Queanbeyan, NSW, 2620, Australia
| | | | - Craig M Forsyth
- School of Chemistry, Monash University, Clayton, VIC, 3800, Australia
| | - Gregory J Wilson
- Energy, CSIRO, 10 Murray Dwyer Cct, Mayfield West, NSW, 2304, Australia
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