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McCain J, Colón KL, Barrett PC, Monro SMA, Sainuddin T, Roque Iii J, Pinto M, Yin H, Cameron CG, McFarland SA. Photophysical Properties and Photobiological Activities of Ruthenium(II) Complexes Bearing π-Expansive Cyclometalating Ligands with Thienyl Groups. Inorg Chem 2019; 58:10778-10790. [PMID: 31386351 DOI: 10.1021/acs.inorgchem.9b01044] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A new family of cyclometalated ruthenium(II) complexes [Ru(N^N)2(C^N)]+ derived from the π-extended benzo[h]imidazo[4,5-f]quinolone ligand appended with thienyl groups (n = 1-4, compounds 1-4) was prepared and its members were characterized for their chemical, photophysical, and photobiological properties. The lipophilicities of 1-4, determined as octanol-water partition coefficients (log Po/w), were positive and increased with the number of thienyl units. The absorption and emission bands of the C^N compounds were red-shifted by up to 200 nm relative to the analogous Ru(II) diimine systems. All of the complexes exhibited dual emission with the intraligand fluorescence (1IL, C^N-based) shifting to lower energies with increasing n and the metal-to-ligand charge transfer phosphorescence (3MLCT, N^N-based) remaining unchanged. Compounds 1-3 exhibited excited state absorption (ESA) profiles consistent with lowest-lying 3MLCT states when probed by nanosecond transient absorption (TA) spectroscopy with 532 nm excitation and had contributions from 1IL(C^N) states with 355 nm excitation. These assignments were supported by the lifetimes observed (<10 ns for the 1IL states and around 20 ns for the 3MLCT states) as well as a noticeable ESA for 3 with 355 nm excitation that did not occur with 532 nm excitation. Compound 4 was the only member of the family with two 3MLCT emissive lifetimes (15, 110 ns), and the TA spectra collected with both 355 and 532 nm excitation was assigned to the 3IL state, which was corroborated by its 4-6 μs lifetime. The ESA for 4 had a rise time of approximately 10 ns and an initial decay of 110 ns, which suggests a possible 3MLCT-3IL excited state equilibrium that results in delayed emission from the 3MLCT state. Compound 4 was nontoxic toward human skin melanoma cells (SKMEL28) in the dark (EC50 = >300 μM); 1-3 were cytotoxic and yielded EC50 values between 1 and 20 μM. The photocytotoxicites with visible light ranged from 87 nM with a phototherapeutic index (PI) of 13 for 1 to approximately 1 μM (PI = >267) for 4. With red light, EC50 values varied from 270 nM (PI = 21) for 3 to 12 μM for 4 (PI = >25). The larger PIs for 4, especially with visible light, were attributed to the much lower dark cytotoxicity for this compound. Because the dark cytotoxicity contributes substantially to the observed photocytotoxicity for 1-3, it was not possible to assess whether the 3IL state of 4 led to a much more potent phototoxic mechanism in the absence of dark toxicity. There was no stark contrast in cellular uptake and accumulation by laser scanning confocal and differential interference contrast microscopy to explain the large differences in dark toxicities between 1-3 and 4. Nevertheless, the study highlights a new family of Ru(II) C^N complexes where π-conjugation beyond a certain point results in low dark cytotoxicity with high photocytotoxicity, opposing the notion that cyclometalated Ru(II) systems are too toxic to be phototherapeutic agents.
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Affiliation(s)
- Julia McCain
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Susan M A Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Tariq Sainuddin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - John Roque Iii
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Mitch Pinto
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Sherri A McFarland
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada.,Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
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Brückmann J, Heidecker AA, Popovic D, Mengele AK, Nauroozi D, Bäuerle P, Rau S. Stille Expands the Family: Access to 5,6‐Bis‐2‐thienyl‐Substituted Phenanthroline Under Mild Conditions for Luminescent Ruthenium Complexes. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Jannik Brückmann
- Institute of Inorganic Chemistry I Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | | | - Duško Popovic
- Institute of Organic Chemistry II and Advanced Materials Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Alexander Klaus Mengele
- Institute of Inorganic Chemistry I Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Djawed Nauroozi
- Institute of Inorganic Chemistry I Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced Materials Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
| | - Sven Rau
- Institute of Inorganic Chemistry I Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
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Monro S, Cameron CG, Zhu X, Colón KL, Yin H, Sainuddin T, Hetu M, Pinto M, Fuller A, Bennett L, Roque J, Sun W, McFarland SA. Synthesis, Characterization and Photobiological Studies of Ru(II) Dyads Derived from α-Oligothiophene Derivatives of 1,10-Phenanthroline. Photochem Photobiol 2018; 95:267-279. [PMID: 30193398 DOI: 10.1111/php.13012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/26/2018] [Indexed: 12/24/2022]
Abstract
Three new bis(2,2'-bipyridine)-heteroleptic Ru(II) dyads incorporating thienyl groups (n = 1-3, compounds 1, 2 and 3, respectively) appended to 1,10-phenanthroline were synthesized and characterized to investigate the impact of n on the photophysical and photobiological properties within the series. All three complexes showed unstructured emission near 618 nm from a triplet metal-to-ligand charge transfer (3 MLCT) state with a lifetime (τem ) of approximately 1 μs. Transient absorption measurements revealed an additional excited state that was nonemissive and long-lived (τTA = 43 μs for 2 and 27 μs for 3), assigned as a triplet intraligand (3 IL) state that was accessible only in 2 and 3. All three complexes were strong singlet oxygen (1 O2 ) sensitizers, with quantum yields (Φ∆ ) for 2 and 3 being the largest (74-78%), and all three were photocytotoxic to cancer cells with visible light activation in the order: 3 > 2 > 1. Cell-free DNA photodamage followed the same trend, where potency increased with decreasing 3 IL energy. Compounds 2 and 3 also showed in vitro photobiological effects with red light (625 nm), where their molar absorptivities were <100 m-1 cm-1 . These findings highlight that Ru(II) dyads derived from α-oligothiophenes directly appended to 1,10-phenanthroline-namely 2 and 3-possess low-lying 3 IL states that are highly photosensitizing, and they may therefore be of interest for photobiological applications such as photodynamic therapy (PDT).
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Affiliation(s)
- Susan Monro
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Xiaolin Zhu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Huimin Yin
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Marc Hetu
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Mitch Pinto
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Anderson Fuller
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Leah Bennett
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - John Roque
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Wenfang Sun
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND
| | - Sherri A McFarland
- Department of Chemistry, Acadia University, Wolfville, NS, Canada.,Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
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Ghosh G, Colón KL, Fuller A, Sainuddin T, Bradner E, McCain J, Monro SMA, Yin H, Hetu MW, Cameron CG, McFarland SA. Cyclometalated Ruthenium(II) Complexes Derived from α-Oligothiophenes as Highly Selective Cytotoxic or Photocytotoxic Agents. Inorg Chem 2018; 57:7694-7712. [PMID: 29927243 DOI: 10.1021/acs.inorgchem.8b00689] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photophysical and photobiological properties of a new class of cyclometalated ruthenium(II) compounds incorporating π-extended benzo[ h]imidazo[4,5- f]quinoline (IBQ) cyclometalating ligands (C^N) bearing thienyl rings ( n = 1-4, compounds 1-4) were investigated. Their octanol-water partition coefficients (log Po/w) were positive and increased with n. Their absorption and emission energies were red-shifted substantially compared to the analogous Ru(II) diimine (N^N) complexes. They displayed C^N-based intraligand (IL) fluorescence and triplet excited-state absorption that shifted to longer wavelengths with increasing n and N^N-based metal-to-ligand charge transfer (MLCT) phosphorescence that was independent of n. Their photoluminescence lifetimes (τem) ranged from 4-10 ns for 1IL states and 12-18 ns for 3MLCT states. Transient absorption lifetimes (τTA) were 5-8 μs with 355 nm excitation, ascribed to 3IL states that became inaccessible for 1-3 with 532 nm excitation (1-3, τTA = 16-17 ns); the 3IL of 4 only was accessible by lower energy excitation, τTA = 3.8 μs. Complex 4 was nontoxic (EC50 > 300 μM) to SK-MEL-28 melanoma cells and CCD1064-Sk normal skin fibroblasts in the dark, while 3 was selectively cytotoxic to melanoma (EC50= 5.1 μM) only. Compounds 1 and 2 were selective for melanoma cells in the dark, with submicromolar potencies (EC50 = 350-500 nM) and selectivity factors (SFs) around 50. The photocytotoxicities of compounds 1-4 toward melanoma cells were similar, but only compounds 3 and 4 displayed significant phototherapeutic indices (PIs; 3, 43; 4, >1100). The larger cytotoxicities for compounds 1 and 2 were attributed to increased cellular uptake and nuclear accumulation, and possibly related to the DNA-aggregating properties of all four compounds as demonstrated by cell-free gel mobility-shift assays. Together, these results demonstrate a new class of thiophene-containing Ru(II) cyclometalated compounds that contain both highly selective chemotherapeutic agents and extremely potent photocytotoxic agents.
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Affiliation(s)
- Goutam Ghosh
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Anderson Fuller
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Tariq Sainuddin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Evan Bradner
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Julia McCain
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Susan M A Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Marc W Hetu
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Sherri A McFarland
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada.,Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
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Barbieri A, Ventura B, Ziessel R. Photoinduced energy-transfer dynamics in multichromophoric arrays containing transition metal complexes and organic modules. Coord Chem Rev 2012. [DOI: 10.1016/j.ccr.2012.02.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Schwartz KR, Chitta R, Bohnsack JN, Ceckanowicz DJ, Miró P, Cramer CJ, Mann KR. Effect of Axially Projected Oligothiophene Pendants and Nitro-Functionalized Diimine Ligands on the Lowest Excited State in Cationic Ir(III) bis-Cyclometalates. Inorg Chem 2012; 51:5082-94. [DOI: 10.1021/ic202573y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Kyle R. Schwartz
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Raghu Chitta
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Jon N. Bohnsack
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Darren J. Ceckanowicz
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Pere Miró
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Christopher J. Cramer
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
| | - Kent R. Mann
- Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota
55455, United States
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7
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Preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and/or disulfur. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Stagni S, Palazzi A, Brulatti P, Salmi M, Muzzioli S, Zacchini S, Marcaccio M, Paolucci F. 5-(2-Thienyl)tetrazolates as Ligands for RuII-Polypyridyl Complexes: Synthesis, Electrochemistry and Photophysical Properties. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000405] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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9
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Shiotsuka M, Tsuji Y, Keyaki K, Nozaki K. Photophysical Properties of Ruthenium(II) Polypyridyl-Gold(I) Ethynyl Dyads and Triads Containing Mono- or Diethynylphenanthroline Incorporated into Gold(I) Triphenylphosphine Organometallics. Inorg Chem 2010; 49:4186-93. [DOI: 10.1021/ic902417m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michito Shiotsuka
- Graduate School of Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
| | - Yasushi Tsuji
- Graduate School of Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
| | - Kazutoshi Keyaki
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190, Gofuku, Toyama-shi, Toyama 930-8555, Japan
| | - Koichi Nozaki
- Department of Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190, Gofuku, Toyama-shi, Toyama 930-8555, Japan
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Mishra A, Ma CQ, Bäuerle P. Functional Oligothiophenes: Molecular Design for Multidimensional Nanoarchitectures and Their Applications. Chem Rev 2009; 109:1141-276. [DOI: 10.1021/cr8004229] [Citation(s) in RCA: 1228] [Impact Index Per Article: 81.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Amaresh Mishra
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Chang-Qi Ma
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced Materials, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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12
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Chaignon F, Buchet F, Blart E, Falkenström M, Hammarström L, Odobel F. Photoinduced electron transfer in ruthenium(ii) trisbipyridine complexes connected to a naphthalenebisimidevia an oligo(phenyleneethynylene) spacer. NEW J CHEM 2009. [DOI: 10.1039/b810856k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Rochford J, Botchway S, McGarvey JJ, Rooney AD, Pryce MT. Photophysical and Electrochemical Properties of meso-Substituted Thien-2-yl Zn(II) Porphyrins. J Phys Chem A 2008; 112:11611-8. [DOI: 10.1021/jp805809p] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jonathan Rochford
- School of Chemical Sciences, SRC for Solar Energy Conversion, Dublin City University, Dublin 9, Ireland, Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, School of Chemistry, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom, and Department of Chemistry, National University of Ireland Maynooth, Co. Kildare, Ireland
| | - Stanley Botchway
- School of Chemical Sciences, SRC for Solar Energy Conversion, Dublin City University, Dublin 9, Ireland, Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, School of Chemistry, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom, and Department of Chemistry, National University of Ireland Maynooth, Co. Kildare, Ireland
| | - John J. McGarvey
- School of Chemical Sciences, SRC for Solar Energy Conversion, Dublin City University, Dublin 9, Ireland, Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, School of Chemistry, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom, and Department of Chemistry, National University of Ireland Maynooth, Co. Kildare, Ireland
| | - A. Denise Rooney
- School of Chemical Sciences, SRC for Solar Energy Conversion, Dublin City University, Dublin 9, Ireland, Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, School of Chemistry, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom, and Department of Chemistry, National University of Ireland Maynooth, Co. Kildare, Ireland
| | - Mary T. Pryce
- School of Chemical Sciences, SRC for Solar Energy Conversion, Dublin City University, Dublin 9, Ireland, Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX, United Kingdom, School of Chemistry, The Queen’s University of Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom, and Department of Chemistry, National University of Ireland Maynooth, Co. Kildare, Ireland
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Packheiser R, Ecorchard P, Rüffer T, Lang H. Mixed-Transition-Metal Acetylides: Synthesis and Characterization of Complexes with up to Six Different Transition Metals Connected by Carbon-Rich Bridging Units. Chemistry 2008; 14:4948-60. [DOI: 10.1002/chem.200701915] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Houarner-Rassin C, Blart E, Buvat P, Odobel F. Solid-state dye-sensitized TiO2 solar cells based on a sensitizer covalently wired to a hole conducting polymer. Photochem Photobiol Sci 2008; 7:789-93. [DOI: 10.1039/b715013j] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Houarner-Rassin C, Chaignon F, She C, Stockwell D, Blart E, Buvat P, Lian T, Odobel F. Synthesis and photoelectrochemical properties of ruthenium bisterpyridine sensitizers functionalized with a thienyl phosphonic acid moiety. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2007.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Bair JS, Harrison RG. Synthesis and Optical Properties of Bifunctional Thiophene Molecules Coordinated to Ruthenium. J Org Chem 2007; 72:6653-61. [PMID: 17676802 DOI: 10.1021/jo070377o] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of unsymmetrical bi- and tetrathiophenes have been synthesized with bipyridine and phosphonic acid functional groups. To do this, phosphonic esters were bonded to thiophenes and the thiophenes coupled to bipyridine. After synthesis of the thienylbipyridines, bis(bipyridine) ruthenium was coordinated to them through the bipyridines. The thienylbipyridines absorb visible light and fluoresce; however, on attachment to ruthenium, both their fluorescence and that of ruthenium are quenched. An additional effect of coordinating ruthenium to the thiophenes is a new absorption band around 470 nm. Variation in oligothiophene length and bipyridine substitution position allowed comparison of the effect of these variables on electronic properties. The longer oligothiophenes display lower-energy absorptions and emissions than that of the shorter thiophenes. In contrast, the position of the bipyridine attachment does not have a large effect on the absorbance or emission wavelength, or on the fluorescence quantum yield.
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Affiliation(s)
- Joseph S Bair
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA
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18
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Houarner-Rassin C, Blart E, Buvat P, Odobel F. Improved efficiency of a thiophene linked ruthenium polypyridine complex for dry dye-sensitized solar cells. J Photochem Photobiol A Chem 2007. [DOI: 10.1016/j.jphotochem.2006.07.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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19
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Belbakra A, Goeb S, De Nicola A, Ziessel R, Sabatini C, Barbieri A, Barigelletti F. Spectroscopic and Redox Properties of Novel d6-Complexes Engineered from All Z-Ethenylthiophene-bipyridine Ligands. Inorg Chem 2007; 46:839-47. [PMID: 17257027 DOI: 10.1021/ic061825y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of quasilinear dinuclear complexes incorporating ruthenium(II)- and osmium(II)-tris(2,2'-bipyridine) units has been prepared in which the individual metal-containing moieties are separated by 3,4-dibutyl-2,5-diethenylthiophene spacers and end-capped by 3,4-dibutyl-2-ethenylthiophene subunits; related ruthenium(II) and osmium(II) mononuclear complexes have also been prepared where one bpy unit is likewise end-capped by 3,4-dibutyl-2-ethenylthiophene subunits [bpy = 2,2'-bipyridine]. Overall, mononuclear species, labeled here Ru and Os, and dinuclear species, RuRu, OsOs, and RuOs, have been prepared and investigated. Their electrochemical behavior has been studied in CH3CN solvent and reveals ethenylthiophene-centered oxidations (irreversible steps at > +1.37 V vs SCE), metal-centered oxidations (reversible steps at +1.30 V vs SCE for Ru(II/III) and +0.82 V vs SCE for Os(II/III)), and successive reduction steps localized at the substituted bpy subunits. The spectroscopic studies performed for the complexes in CH3CN solvent provided optical absorption spectra associated with transitions of ligand-centered nature (LC, from the bpy and ethenylthiophene subunits) and metal-to-ligand charge-transfer nature (MLCT), with the former dominating in the visible region (400-600 nm). While the constituent ethenylthiophene-bpy ligands are strong fluorophores (fluorescence efficiency in CH2Cl2 solvent, phi em = 0.49 and 0.39, for the monomer and the dimer, respectively), only weak luminescence is observed for each complex in acetonitrile at room temperature. In particular, (i) the complexes Ru and RuRu do not emit appreciably, and (ii) the complexes Os, OsOs, and RuOs exhibit triplet emission of 3Os --> L CT character, with phi em in the range from 10-3 to 10-4. These features are rationalized on the basis of the role of nonemissive triplet energy levels, 3Th, centered on the ethenylthiophene spacer. These levels appear to lie lower in energy than the 3Ru --> L CT triplet levels, and in turn higher in energy than the 3Os --> L CT triplet levels, along the sequence 3Ru --> L CT > 3Th > 3Os --> L CT.
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Affiliation(s)
- Abdelhalim Belbakra
- Laboratoire de Chimie Moléculaire, Ecole de Chimie, Polymères, Matériaux, Université Louis Pasteur, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
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Harriman A, Izzet G, Goeb S, De Nicola A, Ziessel R. Photophysical Properties of Ruthenium(II) Tris(2,2‘-bipyridine) Complexes Bearing Conjugated Thiophene Appendages. Inorg Chem 2006; 45:9729-41. [PMID: 17112269 DOI: 10.1021/ic060921w] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A small series of ruthenium(II) tris(2,2'-bipyridine) complexes has been synthesized in which ethynylated thiophene residues are attached to one of the 2,2'-bipyridine ligands. The photophysical properties depend on the conjugation length of the thiophene-based ligand, and in each case, dual emission is observed. The two emitting states reside in thermal equilibrium at ambient temperature and can be resolved by emission spectral curve-fitting routines. This allows the properties of the two states to be evaluated in both fluid butyronitrile solution and a transparent KBr disk. It is concluded that both emitting states are of metal-to-ligand charge-transfer (MLCT) character, and despite the presence of conjugated thiophene residues, there is no indication for a low-lying pi,pi*-triplet state that promotes nonradiative decay of the excited-state manifold. A key feature of these systems is that the conjugation length imposed by the thiophene-based ligand helps to control the rate constants for both radiative and nonradiative decay from the two MLCT triplet states.
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Affiliation(s)
- Anthony Harriman
- Molecular Photonics Laboratory, School of Natural Sciences, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom.
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Formation of Diruthenium(II) Complexes Containing 2,2′;6′,2′′-Terpyridine Domains Possessing Rotationally Restricted Connectivity: The Influence of Shape-Persistence. J Inorg Organomet Polym Mater 2006. [DOI: 10.1007/s10904-006-9001-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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