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Vidal A, Calligaro R, Gasser G, Alberto R, Balducci G, Alessio E. cis-Locked Ru(II)-DMSO Precursors for the Microwave-Assisted Synthesis of Bis-Heteroleptic Polypyridyl Compounds. Inorg Chem 2021; 60:7180-7195. [PMID: 33908778 PMCID: PMC8154425 DOI: 10.1021/acs.inorgchem.1c00240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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We describe a synthetic
strategy for the preparation of bis-heteroleptic
polypyridyl Ru(II) complexes of the type [Ru(L1)2(L2)]2+ (L1 and L2 = diimine ligands) from well-defined Ru(II) precursors.
For this purpose, a series of six neutral, anionic, and cationic cis-locked Ru(II)-DMSO complexes (2–7) of the general formula [Y] fac-[RuX(DMSO–S)3(O–O)]n (where O–O
is a symmetrical chelating anion: oxalate (ox), malonate (mal), acetylacetonate
(acac); X = DMSO–O or Cl–; n = −1/0/+1 depending on the nature and charge of X and O–O;
when present, Y = K+ or PF6–) were efficiently prepared from the well-known cis-[RuCl2(DMSO)4] (1). When treated
with diimine chelating ligands (L1 = bpy, phen, dpphen), the compounds 2–7 afforded the target [Ru(L1)2(O–O)]0/+ complex together with the undesired (and
unexpected) [Ru(L1)3]2+ species. Nevertheless,
we found that the formation of [Ru(L1)3]2+can
be minimized by carefully adjusting the reaction conditions: in particular,
high selectivity toward [Ru(L1)2(O–O)]0/+ and almost complete conversion of the precursor was obtained within
minutes, also on a 100–200 mg scale, when the reactions were
performed in absolute ethanol at 150 °C in a microwave reactor.
Depending on the nature of L1 and concentration, with the oxalate
and malonate precursors, the neutral product [Ru(L1)2(O–O)]
can precipitate spontaneously from the final mixture, in pure form
and acceptable-to-good yields. When spontaneous precipitation of the
disubstituted product does not occur, purification from [Ru(L1)3]2+ can be rather easily accomplished by column
chromatography or solvent extraction. By comparison, under the same
conditions, compound 1 is much less selective, thus demonstrating
that locking the geometry of the precursor through the introduction
of O–O in the coordination sphere of Ru is a valid strategic
approach. By virtue of its proton-sensitive nature, facile and quantitative
replacement of O–O in [Ru(L1)2(O–O)]0/+ by L2, selectively affording [Ru(L1)2(L2)]2+, was accomplished in refluxing ethanol in the presence of
a slight excess of trifluoroacetic acid or HPF6. cis-Locked Ru(II)-DMSO
complexes bearing
a symmetrical chelating anion, such as [K] fac-[RuCl(DMSO−S)3(η2-mal)] (2), are suitable
precursors for the two-step selective preparation of bis-heteroleptic
polypyridyl compounds of the type [Ru(L1)2(L2)]2+ (L1 and L2 = diimine ligands).
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Affiliation(s)
- Alessio Vidal
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Rudy Calligaro
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Gilles Gasser
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemistry, 75005 Paris, France
| | - Roger Alberto
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Gabriele Balducci
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Enzo Alessio
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
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2
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Toyama M, Takizawa T, Morita I, Nagao N, Kuramochi Y, Ishida H. Syntheses and Characterization of a Pair of Isomers of Heteroleptic Bis(Bidentate) Ruthenium(II) Complexes with Two Different Monodentate Ligands. Chemistry 2019; 25:16582-16590. [PMID: 31596008 DOI: 10.1002/chem.201903706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/18/2019] [Indexed: 01/24/2023]
Abstract
Two isomers of heteroleptic bis(bidentate) ruthenium(II) complexes with dimethyl sulfoxide (dmso) and chloride ligands, trans(Cl,Nbpy )- and trans(Cl,NHdpa )-[Ru(bpy)Cl(dmso-S)(Hdpa)]+ (bpy: 2,2'-bipyridine; Hdpa: di-2-pyridylamine), are synthesized. This is the first report on the selective synthesis of a pair of isomers of cis-[Ru(L)(L')XY]n+ (L≠L': bidentate ligands; X≠Y: monodentate ligands). The structures of the ruthenium(II) complexes are clarified by means of X-ray crystallography, and the signals in the 1 H NMR spectra are assigned based on 1 H-1 H COSY spectra. The colors of the two isomers are clearly different in both the solid state and solution: the trans(Cl,Nbpy ) isomer has a deep red color, whereas the trans(Cl,NHdpa ) isomer is yellow. Although both complexes have intense absorption bands at λ≈440-450 nm, only the trans(Cl,Nbpy ) isomer has a shoulder band at λ≈550 nm. DFT calculations indicate that the LUMOs of both isomers are the π* orbitals in the bpy ligand, and that the LUMO level of the trans(Cl,Nbpy ) isomer is lower than that of the trans(Cl,NHdpa ) isomer due to the trans effect of the Cl ligand; thus resulting in the appearance of the shoulder band. The HOMO levels are almost the same in both isomers. The energy levels are experimentally supported by cyclic voltammograms, in which these isomers have different reduction potentials and similar oxidation potentials.
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Affiliation(s)
- Mari Toyama
- Current address: Osaka Prefecture University College of Technology, 26-12 Saiwaicho, Neyagawa, Osaka, 572-8572, Japan.,Department of Chemistry of Functional Molecules, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada, Kobe, 658-8501, Japan.,Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Takako Takizawa
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Itaru Morita
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Noriharu Nagao
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Yusuke Kuramochi
- Department of Chemistry, Graduate School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan.,Current address: Department of Chemistry, Faculty of Science Division II, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Hitoshi Ishida
- Department of Chemistry, Graduate School of Science, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan
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3
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Kosgei GK, Livshits MY, Canterbury TR, Rack JJ, Brewer KJ. Nanosecond transient absorption spectroscopy of a Ru polypyridine phenothiazine dyad. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.03.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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4
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5
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Naskar S, Pakhira B, Mishra D, Mitra P, Chattopadhyay SK, Naskar S. Synthesis, characterization and theoretical studies of the heteroleptic Ruthenium(II) complexes of 2,6-bis(benzimidazolyl)pyridine. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.07.058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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6
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Hankache J, Niemi M, Lemmetyinen H, Wenger OS. Photoinduced Electron Transfer in Linear Triarylamine–Photosensitizer–Anthraquinone Triads with Ruthenium(II), Osmium(II), and Iridium(III). Inorg Chem 2012; 51:6333-44. [DOI: 10.1021/ic300558s] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Jihane Hankache
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, D-37077
Göttingen, Germany
| | - Marja Niemi
- Tampere University of Technology, Department
of Chemistry and Bioengineering, P.O. Box 541, FIN-33101 Tampere,
Finland
| | - Helge Lemmetyinen
- Tampere University of Technology, Department
of Chemistry and Bioengineering, P.O. Box 541, FIN-33101 Tampere,
Finland
| | - Oliver S. Wenger
- Georg-August-Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, D-37077
Göttingen, Germany
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7
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Zhang GJ, Gan X, Xu QQ, Chen Y, Zhao XJ, Qin B, Lv XJ, Lai SW, Fu WF, Che CM. Photophysical and electrochemical properties of platinum(ii) complexes bearing a chromophore–acceptor dyad and their photocatalytic hydrogen evolution. Dalton Trans 2012; 41:8421-9. [DOI: 10.1039/c2dt30415e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Gui-Ju Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, CAS-HKU Joint Laboratory on New Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Peking 100190, PR China
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8
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Ajayakumar G, Kobayashi M, Masaoka S, Sakai K. Light-induced charge separation and photocatalytic hydrogen evolution from water using RuIIPtII-based molecular devices: Effects of introducing additional donor and/or acceptor sites. Dalton Trans 2011; 40:3955-66. [DOI: 10.1039/c0dt01673j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Roy AS, Biswas MK, Weyhermüller T, Ghosh P. Unsymmetrical diimine complexes of iron(ii) and manganese(ii): synthesis, structure and photoluminescence of an isomer. Dalton Trans 2011; 40:146-55. [DOI: 10.1039/c0dt00883d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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10
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Kumar R, Karlsson S, Streich D, Rolandini Jensen A, Jäger M, Becker HC, Bergquist J, Johansson O, Hammarström L. Vectorial Electron Transfer in Donor-Photosensitizer-Acceptor Triads Based on Novel Bis-tridentate Ruthenium Polypyridyl Complexes. Chemistry 2010; 16:2830-42. [DOI: 10.1002/chem.200902716] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Lai SW, Chen Y, Kwok WM, Zhao XJ, To WP, Fu WF, Che CM. Organoplatinum(II) Complexes with Chromophore-Acceptor Dyad Studied by Ultrafast Time-Resolved Absorption Spectroscopy. Chem Asian J 2010; 5:60-5. [DOI: 10.1002/asia.200900304] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Jarosz P, Lotito K, Schneider J, Kumaresan D, Schmehl R, Eisenberg R. Platinum(II) Terpyridyl-Acetylide Dyads and Triads with Nitrophenyl Acceptors via a Convenient Synthesis of a Boronated Phenylterpyridine. Inorg Chem 2009; 48:2420-8. [DOI: 10.1021/ic801769v] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul Jarosz
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Kenneth Lotito
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Jacob Schneider
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Duraisamy Kumaresan
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Russell Schmehl
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - Richard Eisenberg
- Department of Chemistry, University of Rochester, Rochester, New York 14627, and Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
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13
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Philippopoulos AI, Terzis A, Raptopoulou CP, Catalano VJ, Falaras P. Synthesis, Characterization, and Sensitizing Properties of Heteroleptic RuII Complexes Based on 2,6-Bis(1-pyrazolyl)pyridine and 2,2′-Bipyridine-4,4′-dicarboxylic Acid Ligands. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700287] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Arachchige SM, Brewer KJ. A donor–chromophore complex containing the polyazine bridging ligand 2,3-bis(2-pyridyl)pyrazine. INORG CHEM COMMUN 2007. [DOI: 10.1016/j.inoche.2007.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Nickita N, Belousoff MJ, Bhatt AI, Bond AM, Deacon GB, Gasser G, Spiccia L. Synthesis, Structure, Spectroscopic Properties, and Electrochemical Oxidation of Ruthenium(II) Complexes Incorporating Monocarboxylate Bipyridine Ligands. Inorg Chem 2007; 46:8638-51. [PMID: 17880205 DOI: 10.1021/ic700796m] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Ru(bpy)(2)(Mebpy-COOH)](PF(6))(2).3H(2)O (1), [Ru(phen)(2)(Mebpy-COOH)](ClO(4))(2).5H(2)O (2), [Ru(dppz)(2)(Mebpy-COOH)]Cl(2).9H(2)O (3), and [Ru(bpy)(dppz)(Mebpy-COOH)](PF(6))(2).5H(2)O (4) (bpy = 2,2'-bipyridine, Mebpy-COOH = 4'-methyl-2,2'-bipyridine-4-carboxylic acid, phen = 1,10-phenanthroline, dppz = dipyrido[3,2,-a;2',3-c]phenazine) have been synthesized and characterized spectroscopically and by microanalysis. The [Ru(Mebpy-COOH)(CO)(2)Cl(2)].H(2)O intermediate was prepared by reaction of the monocarboxylic acid ligand, Mebpy-COOH, with [Ru(CO)(2)Cl(2)](n), and the product was then reacted with either bpy, phen, or dppz in the presence of an excess of trimethylamine-N-oxide (Me(3)NO), as the decarbonylation agent, to generate 1, 2, and 3, respectively. For compound 4, [Ru(bpy)(CO)Cl(2)](2) was reacted with Mebpy-COOH to yield [Ru(bpy)(Mebpy-COOH)(CO)Cl](PF(6)).H(2)O as a mixture of two main geometric isomers. Chemical decarbonylation in the presence of dppz gave 4 also as a mixture of two isomers. Electrochemical and spectrophotometric studies indicated that complexes 1 and 2 were present as a mixture of protonated and deprotonated forms in acetonitrile solution because of water of solvation in the isolated solid products. The X-ray crystal structure determination on crystals of [Ru(bpy)2(MebpyCOO)][Ru(bpy)(2)(MebpyCOOH)](3)(PF(6))(7), 1a, and [Ru(phen)(2)(MebpyCOO)](ClO(4)).6H(2)O, 2a, obtained from solutions of 1 and 2, respectively, revealed that 1a consisted of a mixture of protonated and deprotonated forms of the complex in a 1:3 ratio and that 2a consisted of the deprotonated derivative of 2. A distorted octahedral geometry for the Ru(II) centers was found for both complexes. Upon excitation at 450 nm, MeCN solutions of the protonated complexes 1-4 were found to exhibit emission bands in the 635-655 nm range, whereas the corresponding emission maxima of their deprotonated forms were observed at lower wavelengths. Protonation/deprotonation effects were also observed in the luminescence and electrochemical behavior of complexes 1-4. Comprehensive electrochemical studies in acetonitrile show that the ruthenium centers on 1, 2, 3, and 4 are oxidized from Ru(II) to Ru(III) with reversible potentials at 917, 929, 1052, and 1005 mV vs Fc(0/+) (Fc = ferrocene), respectively. Complexes 1 and 2 also exhibit an irreversible oxidation process in acetonitrile, and all compounds undergo ligand-based reduction processes.
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Affiliation(s)
- Nickita Nickita
- School of Chemistry and Centre for Green Chemistry, Monash University, Victoria 3800, Australia
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16
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Fleming CN, Dattelbaum DM, Thompson DW, Ershov AY, Meyer TJ. Excited State Intervalence Transfer in a Rigid Polymeric Film. J Am Chem Soc 2007; 129:9622-30. [PMID: 17630735 DOI: 10.1021/ja068074j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ligand-bridged complex cis,cis-[(bpy)2ClRu(pz)RuCl(bpy)2]2+ as the PF6- salt, (1)(PF6)2, is stabilized toward photochemical ligand loss in poly(methyl methacrylate) (PMMA). Stabilization allows measurement of metal-to-ligand charge transfer (MLCT) photophysical properties--emission and transient absorption. This includes appearance of an intervalence transfer absorption band in the near IR spectrum of the photochemically prepared, mixed valence form, [(bpy)2ClRuIII(pz(-*))RuIICl(bpy)2](PF6)2* (1*(PF6)2). Comparison of its IT band properties with those of ground state cis,cis-(bpy)2ClRuIII(pz)RuIICl(bpy)2]3+ in CD3CN allows a comparison to be made between pz and pz(-*) as bridging ligands. A model based on differences between rigid and fluid media provides an explanation for decreased IT band energies and widths in PMMA and provides important insight into electron transfer in rigid media.
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Affiliation(s)
- Cavan N Fleming
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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Puntoriero F, Nastasi F, Cavazzini M, Quici S, Campagna S. Coupling synthetic antenna and electron donor species: A tetranuclear mixed-metal Os(II)–Ru(II) dendrimer containing six phenothiazine donor subunits at the periphery. Coord Chem Rev 2007. [DOI: 10.1016/j.ccr.2006.04.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Borgström M, Shaikh N, Johansson O, Anderlund MF, Styring S, Akermark B, Magnuson A, Hammarström L. Light Induced Manganese Oxidation and Long-Lived Charge Separation in a Mn2II,II−RuII(bpy)3−Acceptor Triad. J Am Chem Soc 2005; 127:17504-15. [PMID: 16332103 DOI: 10.1021/ja055243b] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photoinduced electron-transfer reactions in a Mn2II,II-RuII-NDI triad (1) ([Mn2(bpmp)(OAc)2]+, bpmp = 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenolate and OAc = acetate, RuII = tris-bipyridine ruthenium(II), and NDI = naphthalenediimide) have been studied by time-resolved optical and EPR spectroscopy. Complex 1 is the first synthetically linked electron donor-sensitizer-acceptor triad in which a manganese complex plays the role of the donor. EPR spectroscopy was used to directly demonstrate the light induced formation of both products: the oxidized manganese dimer complex (Mn2II,III) and the reduced naphthalenediimide (NDI*-) acceptor moieties, while optical spectroscopy was used to follow the kinetic evolution of the [Ru(bpy)3]2+ intermediate states and the NDI*- radical in a wide temperature range. The average lifetime of the NDI*- radical is ca. 600 micros at room temperature, which is at least 2 orders of magnitude longer than that for previously reported triads based on a [Ru(bpy)3]2+ photosensitizer. At 140 K, this intramolecular recombination was dramatically slowed, displaying a lifetime of 0.1-1 s, which is comparable to many of the naturally occurring charge-separated states in photosynthetic reaction centra. It was found that the long recombination lifetime could be explained by an unusually large reorganization energy (lambda approximately 2.0 eV), due to a large inner reorganization of the manganese complex. This makes the recombination reaction strongly activated despite the large driving force (Delta-G degrees = 1.07 eV). Thus, the intrinsic properties of the manganese complex are favorable for creating a long-lived charge separation in the "Marcus normal region" also when the charge separated state energy is high.
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Affiliation(s)
- Magnus Borgström
- Department of Physical Chemistry, Uppsala University, P.O. Box 579, SE-751 23 Uppsala, Sweden
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19
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Chakraborty S, Wadas TJ, Hester H, Schmehl R, Eisenberg R. Platinum Chromophore-Based Systems for Photoinduced Charge Separation: A Molecular Design Approach for Artificial Photosynthesis. Inorg Chem 2005; 44:6865-78. [PMID: 16180842 DOI: 10.1021/ic0505605] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced charge separation is a fundamental step in photochemical energy conversion. In the design of molecularly based systems for light-to-chemical energy conversion, this step is studied through the construction of two- and three-component systems (dyads and triads) having suitable electron donor and acceptor moieties placed at specific positions on a charge-transfer chromophore. The most extensively studied chromophores in this regard are ruthenium(II) tris(diimine) systems with a common 3MLCT excited state, as well as related ruthenium(II) bis(terpyridyl) systems. This Forum contribution focuses on dyads and triads of an alternative chromophore, namely, platinum(II) di- and triimine systems having acetylide ligands. These d8 chromophores all possess a 3MLCT excited state in which the lowest unoccupied molecular orbital is a pi orbital on the heterocyclic aromatic ligand. The excited-state energies of these Pt(II) chromophores are generally higher than those found for the ruthenium(II) tris(diimine) systems, and the directionality of the charge transfer is more certain. The first platinum diimine bis(arylacetylide) triad, constructed by attaching phenothiazene donors to the arylacetylide ligands and a nitrophenyl acceptor to 5-ethynylphenanthroline of the chromophore, exhibited a charge-separated state of 75-ns duration. The first Pt(tpy)(arylacetylide)+-based triad contains a trimethoxybenzamide donor and a pyridinium acceptor and has been structurally characterized. The triad has an edge-to-edge separation between donor and acceptor fragments of 27.95 Angstroms. However, while quenching of the emission is complete for this system, transient absorption (TA) studies reveal that charge transfer does not move onto the pyridinium acceptor. A new set of triads described in detail here and having the formula [Pt(NO2phtpy)(p-C triple-bond C-C6H4CH2(PTZ-R)](PF6), where NO2phtpy = 4'-{4-[2-(4-nitrophenyl)vinyl]phenyl}-2,2';6',2''-terpyridine and PTZ = phenothiazine with R = H, OMe, possess an unsaturated linkage between the chromophore and a nitrophenyl acceptor. While the parent chromophore [Pt(ttpy)(C triple-bond CC6H5)]PF6 is brightly luminescent in a fluid solution at 298 K, the triads exhibit complete quenching of the emission, as do the related donor-chromophore (D-C) dyads. Electrochemically, the triads and D-C dyads exhibit a quasi-reversible oxidation wave corresponding to the PTZ ligand, while the R = H triad and related C-A dyad display a facile quasi-reversible reduction assignable to the acceptor. TA spectroscopy shows that one of the triads possesses a long-lived charge-separated state of approximately 230 ns.
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Affiliation(s)
- Soma Chakraborty
- Department of Chemistry, University of Rochester, New York 14627, USA
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Chakraborty S, Wadas TJ, Hester H, Flaschenreim C, Schmehl R, Eisenberg R. Synthesis, Structure, Characterization, and Photophysical Studies of a New Platinum Terpyridyl-Based Triad with Covalently Linked Donor and Acceptor Groups. Inorg Chem 2005; 44:6284-93. [PMID: 16124807 DOI: 10.1021/ic050688m] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new terpyridyl-containing Pt triad [Pt(pytpy)(p-CC-C6H4-NH-CO-C6H2(OMe)3)](PF6)2 (4), where pytpy = 4'-(4-pyridin-1-ylmethylphenyl)-[2,2';6',2' ']terpyridine and p-CC-C6H4-NH-CO-C6H2(OMe)3 = N-(4-ethynylphenyl)-3,4,5-trimethoxybenzamide, has been synthesized and structurally characterized. The related donor-chromophore dyad [Pt(ttpy)(p-CC-C6H4-NH-CO-C6H2(OMe)3)]PF6 2, where ttpy = 4'-p-tolyl-[2,2';6',2' ']terpyridine, and the chromophore-acceptor dyad [Pt(pytpy)(CCC6H5)](PF6)2 (3), where CCC6H5 = ethynylbenzene, have also been studied. The multistep syntheses culminate with a CuI-catalyzed coupling reaction of the respective acetylene with either [Pt(ttpy)Cl]PF6 or [Pt(pytpy)Cl](PF6)2. X-ray and spectroscopic studies support assignment of a distorted square planar environment around the Pt(II) ion with three of its coordination sites occupied by the terpyridyl N-donors and the fourth coordination site occupied by the acetylenic carbon. Although the parent compound [Pt(ttpy)(CCC6H5)]PF6 (1) is brightly luminescent in fluid solution at 298 K, dyad 2 as well as triad 4 exhibit complete quenching of the emission. The chromophore-acceptor (C-A) dyad 3 displays weak solution luminescence at room temperature with a phi(rel)(em) of 0.011 (using Ru(bpy)3(2+) as a standard with phi(rel)(em) = 0.062). Electrochemically, the donor-chromophore (D-C) dyad and the donor-chromophore-acceptor (D-C-A) triad exhibit both metal-based and donor ligand-based oxidations, whereas the triad and the C-A dyad show the expected pyridinium- and terpyridine-based reductions. Transient absorption studies of the dyad and triad systems indicate that although the trimethoxybenzene group acts as a reductive donor, in the present system, the pyridinium group fails to act as an acceptor.
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Affiliation(s)
- Soma Chakraborty
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
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21
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Sykora M, Yang JC, Meyer TJ. Effect of Surface Immobilization on Intramolecular and Intermolecular Electron Transfer in a Chromophore−Donor−Acceptor Assembly. J Phys Chem B 2005; 109:1499-504. [PMID: 16851121 DOI: 10.1021/jp040260t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A chromophore-donor-acceptor assembly [Ru(bpyCOOH)(bpyCH(2)MV(2+)) (bpyCH(2)PTZ)](4+)(1) (where bpyCOOH = 4-carboxylic acid-4'-methyl-2,2'-bipyridine, bpyCH(2)MV(2+) = 1-[(4'-methyl-2,2'-bipyridin-4-yl)methyl]-1'-methyl-4,4'-bipyridinediium, and bpyCH(2)PTZ = 10-[(4'-methyl-2,2'-bipyridin-4-yl)methyl]phenothiazine) has been adsorbed on the surface of nanocrystalline ZrO(2) and its excited state properties studied by emission and transient absorption spectroscopy. In deaerated acetonitrile solution, the complex emits weakly with an emission quantum yield of phi(em) approximately equal to 0.01 with an excited-state lifetime of tau approximately equal to 20 ps. Emission from the surface-adsorbed complex is intense, with phi(em) approximately equal to 0.4 and tau approximately equal to 40 ns. The increase in emission on the surface is likely due to a significant inhibition to the electron-transfer quenching of the metal-to-ligand charge transfer (MLCT) excited state caused by surface adsorption-induced changes in the redox potentials. Transient (nanosecond time scale) absorption monitoring, following laser flash photolysis, reveals the presence of a transient or transients that are formed during the flash. Transient spectral changes that occur during and after the flash are consistent with the formation and decay of the intermediate ZrO(2)-[Ru(bpyCOOH)(bpyCH(2)MV(+*))(bpyCH(2)PTZ(+*))](4+). It returns to the ground state by both intramolecular and intermolecular processes. Intramolecular electron transfer occurs with k(BET) = 6.3 x 10(6) s(-1) (tau = 160 ns), which is comparable to the rate constant for back-electron transfer in solution. The back-electron transfer is a second-order process and is much slower, with k(BET) = 390 M(-1) s(-1) (tau = 2.6 ms).
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Affiliation(s)
- Milan Sykora
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA
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22
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Alessio E. Synthesis and Reactivity of Ru-, Os-, Rh-, and Ir-Halide−Sulfoxide Complexes. Chem Rev 2004; 104:4203-42. [PMID: 15352790 DOI: 10.1021/cr0307291] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Enzo Alessio
- Dipartimento di Scienze Chimiche, Università di Trieste, 34127, Italy.
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23
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Spiccia L, Deacon GB, Kepert CM. Synthetic routes to homoleptic and heteroleptic ruthenium(II) complexes incorporating bidentate imine ligands. Coord Chem Rev 2004. [DOI: 10.1016/j.ccr.2004.04.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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24
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Kepert CM, Deacon GB, Sahely N, Spiccia L, Fallon GD, Skelton BW, White AH. Synthesis of heteroleptic bis(diimine)carbonylchlororuthenium(II) complexes from photodecarbonylated precursors. Inorg Chem 2004; 43:2818-27. [PMID: 15106968 DOI: 10.1021/ic0351895] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactions of bidentate diimine ligands (L2) with binuclear [Ru(L1)(CO)Cl2]2 complexes [L1 not equal to L2 = 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (4,4'-Me2bpy), 5,5'-dimethyl-2,2'-bipyridine (5,5'-Me2bpy), 1,10-phenanthroline (phen), 4,7-dimethyl-1,10-phenanthroline (4,7-Me2phen), 5,6-dimethyl-1,10-phenanthroline (5,6-Me2phen), di(2-pyridyl)ketone (dpk), di(2-pyridyl)amine (dpa)] result in cleavage of the dichloride bridge and the formation of cationic [Ru(L1)(L2)(CO)Cl]+ complexes. In addition to spectroscopic characterization, the structures of the [Ru(bpy)(phen)(CO)Cl]+, [Ru(4,4'-Me2bpy)(5,6-Me2phen)(CO)Cl]+ (as two polymorphs), [Ru(4,4'-Me2bpy)(4,7-Me2phen)(CO)Cl]+, [Ru(bpy)(dpa)(CO)Cl]+, [Ru(5,5'-Me2bpy)(dpa)(CO)Cl]+, [Ru(bpy)(dpk)(CO)Cl]+, and [Ru(4,4'-Me2bpy)(dpk)(CO)Cl]+ cations were confirmed by single crystal X-ray diffraction studies. In each case, the structurally characterized complex had the carbonyl ligand trans to a nitrogen from the incoming diimine ligand, these complexes corresponding to the main isomers isolated from the reaction mixtures. The synthesis of [Ru(4,4'-Me2bpy)(5,6-Me2bpy)(CO)(NO3)]+ from [Ru(4,4'-Me2bpy)(5,6-Me2bpy)(CO)Cl]+ and AgNO3 demonstrates that exchange of the chloro ligand can be achieved.
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Borgström M, Johansson O, Lomoth R, Baudin HB, Wallin S, Sun L, Akermark B, Hammarström L. Electron donor-acceptor dyads and triads based on tris(bipyridine)ruthenium(II) and benzoquinone: synthesis, characterization, and photoinduced electron transfer reactions. Inorg Chem 2003; 42:5173-84. [PMID: 12924888 DOI: 10.1021/ic020606j] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two electron donor-acceptor triads based on a benzoquinone acceptor linked to a light absorbing [Ru(bpy)(3)](2+) complex have been synthesized. In triad 6 (denoted Ru(II)-BQ-Co(III)), a [Co(bpy)(3)](3+) complex, a potential secondary acceptor, was linked to the quinone. In the other triad, 8 (denoted PTZ-Ru(II)-BQ), a phenothiazine donor was linked to the ruthenium moiety. The corresponding dyads Ru(II)-BQ (4) and PTZ-Ru(II) (9) were prepared for comparison. Upon light excitation in the visible band of the ruthenium moiety, electron transfer to the quinone occurred with a rate constant k(f) = 5 x 10(9) s(-)(1) (tau(f) = 200 ps) in all the quinone containing complexes. Recombination to the ground state followed, with a rate constant k(b) approximately 4.5 x 10(8) s(-)(1) (tau(b) approximately 2.2 ns), for both Ru(II)-BQ and Ru(II)-BQ-Co(III) with no indication of a charge shift to generate the reduced Co(II) moiety. In the PTZ-Ru(II)-BQ triad, however, the initial charge separation was followed by a rapid (k > 5 x 10(9) s(-)(1)) electron transfer from the phenothiazine moiety to give the fairly long-lived PTZ(*)(+)-Ru(II)-BQ(*)(-) state (tau = 80 ns) in unusually high yield for a [Ru(bpy)(3)](2+)-based triad (> 90%), that lies at DeltaG degrees = 1.32 eV relative to the ground state. Unfortunately, this triad turned out to be rather photolabile. Interestingly, coupling between the oxidized PTZ(*)(+) and the BQ(*)(-) moieties seemed to occur. This discouraged further extension to incorporate more redox active units. Finally, in the dyad PTZ-Ru(II) a reversible, near isoergonic electron transfer was observed on excitation. Thus, a quasiequilibrium was established with an observed time constant of 7 ns, with ca. 82% of the population in the PTZ-Ru(II) state and 18% in the PTZ(*)(+)-Ru(II)(bpy(*)(-)) state. These states decayed in parallel with an observed lifetime of 90 ns. The initial electron transfer to form the PTZ(*)(+)-Ru(II)(bpy(*)(-)) state was thus faster than what would have been inferred from the Ru(II) emission decay (tau = 90 ns). This result suggests that reports for related PTZ-Ru(II) and PTZ-Ru(II)-acceptor complexes in the literature might need to be reconsidered.
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Affiliation(s)
- Magnus Borgström
- Department of Physical Chemistry, BMC, Uppsala University, PO Box 579, SE-751 23 Uppsala, Sweden
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McGarrah JE, Eisenberg R. Dyads for photoinduced charge separation based on platinum diimine bis(acetylide) chromophores: synthesis, luminescence and transient absorption studies. Inorg Chem 2003; 42:4355-65. [PMID: 12844308 DOI: 10.1021/ic034026d] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The platinum diimine bis(acetylide) chromophore was utilized to explore photoinduced intramolecular reductive quenching with phenothiazine donors in chromophore-donor dyad complexes. Compounds of the general formula Pt(X(2)-bpy)(C triple bond C-p-C(6)H(4)CH(2)(D))(2) (where D = phenothiazine (PTZ) or trifluromethylphenothiazine (TPZ) and X = (t)Bu or CO(2)Et) were synthesized from the corresponding Pt(X(2)-bpy)Cl(2) and aryl acetylene by a CuI-catalyzed coupling reaction. Solvent dependence was explored for the system with X = (t)Bu in MeCN, CH(2)Cl(2), EtOAc, and toluene. Electron transfer quenching of the (3)MLCT excited state of the platinum diimine bis(acetylide) takes place in MeCN leaving no intrinsic emission from the excited state, but in toluene both the PTZ and TPZ dyad complexes exhibit no emission quenching. Picosecond pump-probe transient absorption (TA) experiments were used to monitor decay of the (3)MLCT excited state and electron transfer to form the charge-separated (CS) state. Electrochemical measurements were used to estimate the driving force for charge recombination (CR), with deltaE(CR) based on the reduction potential corresponding to Pt(X(2)-bpy)(C triple bond C-Ar)(2) --> Pt(X(2)-bpy(*)(-))(C triple bond C-Ar)(2) and the oxidation corresponding to donor --> donor(*)(+). Kinetic information from the TA measurements was used to correlate rate and driving force with the electron transfer reactions. Concomitant with the decay of the (3)MLCT excited state was the observation of a transient absorption at ca. 500 nm due to formation of the PTZ or TPZ radical cation in the CS state, with the rate of charge separation, k(CS), being 1.8 x 10(9) to 2 x 10(10) s(-1) for the three dyads explored in MeCN and 1:9 CH(2)Cl(2)/MeCN. The fastest rate of CR occurs for X = CO(2)Et and D = PTZ, the compound with smallest deltaE(CR) = 1.71 V. The rate of CR for dyads with X = (t)Bu and D = PTZ or TPZ was estimated to be 1.7-2.0 x 10(8) s(-1) in MeCN. The slower rate corresponds to a greater driving force for CR, deltaE(CR) = 2.18 and 2.36 V for D = PTZ and TPZ, respectively, suggesting that the driving force for charge recombination places it in the Marcus inverted region.
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Affiliation(s)
- James E McGarrah
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA
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Johansson O, Borgström M, Lomoth R, Palmblad M, Bergquist J, Hammarström L, Sun L, Akermark B. Electron donor-acceptor dyads based on ruthenium(II) bipyridine and terpyridine complexes bound to naphthalenediimide. Inorg Chem 2003; 42:2908-18. [PMID: 12716183 DOI: 10.1021/ic020420k] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two series of photosensitizer-electron acceptor complexes have been synthesized and fully characterized: ruthenium(II) tris(bipyridine) ([Ru(II)(bpy)(2)(bpy-X-NDI)], where X = -CH(2)-, tolylene, or phenylene, bpy is 2,2'-bipyridine, and NDI is naphthalenediimide) and ruthenium(II) bis(terpyridine) ([Ru(II)(Y-tpy)(tpy-X-NDI)], where Y = H or tolyl and X = tolylene or phenylene, and tpy = 2,2':6',2' '-terpyridine). The complexes have been studied by cyclic and differential pulse voltammetry and by steady state and time-resolved absorption and emission techniques. Rates for forward and backward electron transfer have been investigated, following photoexcitation of the ruthenium(II) polypyridine moiety. The terpyridine complexes were only marginally affected by the linked diimide unit, and no electron transfer was observed. In the bipyridine complexes we achieved efficient charge separation. For the complexes containing a phenyl link between the ruthenium(II) and diimide moieties, our results suggest a biphasic forward electron-transfer reaction, in which 20% of the charge-separated state was formed via population of the naphthalenediimide triplet state.
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Affiliation(s)
- Olof Johansson
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden
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28
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Pellegrin Y, Berg K, Blondin G, Anxolabéhère-Mallart E, Leibl W, Aukauloo A. A Rigid Molecular Scaffold Affixing a (Polypyridine)ruthenium(II)- and a Nickel(II)-Containing Complex: Spectroscopic Evidence for a Weakly Coupled Bichromophoric System. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200561] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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29
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Haid R, Gutmann R, Stampfl T, Langes C, Czermak G, Kopacka H, Ongania KH, Brüggeller P. Unexpected photochemical reactivity of ruthenium(II) polypyridine complexes induced by a bis(bidentate) phosphine. Inorg Chem 2001; 40:7099-104. [PMID: 11754298 DOI: 10.1021/ic010545+] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R Haid
- Institute of General, Inorganic and Theoretical Chemistry and Institute of Organic Chemistry, University of Innsbruck, Innrain 52a, 6020 Innsbruck, Austria
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New Ru(II) phenanthroline complex photosensitizers having different number of carboxyl groups for dye-sensitized solar cells. J Photochem Photobiol A Chem 2001. [DOI: 10.1016/s1010-6030(01)00570-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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31
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Dı́az R, Reyes O, Francois A, Leiva AM, Loeb B. Synthesis of a new polypyridinic highly conjugated ligand with electron-acceptor properties. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01289-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Haider JM, Chavarot M, Weidner S, Sadler I, Williams RM, De Cola L, Pikramenou Z. Metallocyclodextrins as building blocks in noncovalent assemblies of photoactive units for the study of photoinduced intercomponent processes. Inorg Chem 2001; 40:3912-21. [PMID: 11466049 DOI: 10.1021/ic0100166] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclodextrin cups have been employed to build supramolecular systems consisting of metal and organic photoactive/redox-active components; the photoinduced communication between redox-active units assembled in water via noncovalent interactions is established. The functionalization of a beta-cyclodextrin with a terpyridine unit, ttp-beta-CD, is achieved by protection of all but one of the hydroxyl groups by methylation and attachment of the ttp unit on the free primary hydroxyl group. The metalloreceptors [(beta-CD-ttp)Ru(ttp)][PF(6)](2), [(beta-CD-ttp)Ru(tpy)][PF(6)](2), and [Ru(beta-CD-ttp)(2)][PF(6)](2) are synthesized and fully characterized. The [(beta-CD-ttp)Ru(ttp)][PF(6)](2) metalloreceptor exhibits luminescence in water, centered at 640 nm, from the (3)MLCT state with a lifetime of 1.9 ns and a quantum yield of Phi = 4.1 x 10(-)(5). Addition of redox-active quinone guests AQS, AQC, and BQ to an aqueous solution of [(beta-CD-ttp)Ru(ttp)](2+) results in quenching of the luminescence up to 40%, 20%, and 25%, respectively. Measurement of the binding strength indicates that, in saturation conditions, 85% for AQS and 77% for AQC are bound. The luminescence quenching is attributed to an intercomponent electron transfer from the appended ruthenium center to the quinone guest inside the cavity. Control experiments demonstrate no bimolecular quenching at these conditions. A photoactive osmium metalloguest, [Os(biptpy)(tpy)][PF(6)], is designed with a biphenyl hydrophobic tail for insertion in the cyclodextrin cavity. The complex is luminescent at room temperature with an emission band maximum at 730 nm and a lifetime of 116 ns. The osmium(III) species are formed for the study of photoinduced electron transfer upon their assembly with the ruthenium cyclodextrin, [(beta-CD-ttp)Ru(ttp)](2+). Time-resolved spectroscopy studies show a short component of 10 ps, attributed to electron transfer from Ru(II) to Os(III) giving an electron transfer rate 9.5 x 10(9) s(-)(1).
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Affiliation(s)
- J M Haider
- School of Chemistry, The University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
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Sykora M, Maxwell KA, DeSimone JM, Meyer TJ. Mimicking the antenna-electron transfer properties of photosynthesis. Proc Natl Acad Sci U S A 2000; 97:7687-91. [PMID: 10884400 PMCID: PMC16604 DOI: 10.1073/pnas.97.14.7687] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A molecular assembly based on derivatized polystyrene is described, which mimics both the light-harvesting and energy-conversion steps of photosynthesis. The system is unique in that the two key parts of a photosynthetic system are incorporated in a functional assembly constructed from polypyridine complexes of Ru(II). This system is truly artificial, as none of the components used in construction of the assembly are present in a natural photosynthetic system. Quantitative evaluation of the energy and electron transfer dynamics after transient irradiation by visible light offers important insights into the mechanisms of energy transport and electron transfer that lead to photosynthetic light-to-chemical energy conversion.
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Affiliation(s)
- M Sykora
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290
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