1
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Waly SMA, Benniston AC, Harriman A. Deducing the conformational space for an octa-proline helix. Chem Sci 2024; 15:1657-1671. [PMID: 38303943 PMCID: PMC10829019 DOI: 10.1039/d3sc05287g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/20/2023] [Indexed: 02/03/2024] Open
Abstract
A molecular dyad, PY-P8-PER, comprising a proline octamer sandwiched between pyrene and perylene terminals has been synthesized in order to address the dynamics of electronic energy transfer (EET) along the oligo-proline chain. A simple pyrene-based control compound equipped with a bis-proline attachment serves as a reference for spectroscopic studies. The N-H NMR signal at the terminal pyrene allows distinction between cis and trans amides and, although the crystal structure for the control has the trans conformation, temperature-dependent NMR studies provide clear evidence for trans/cis isomerisation in D6-DMSO. Polar solvents tend to stabilise the trans structure for the pyrene amide group, even for longer oligo-proline units. Circular dichroism shows that the proline spacer for PY-P8-PER exists mainly in the all-trans geometry in methanol. Preferential excitation of the pyrene chromophore is possible at wavelengths in the 320-350 nm range and, for the dyad, is followed by efficacious EET to the perylene emitter. The probability for intramolecular EET, obtained from analysis of steady-state spectroscopic data, is ca. 80-90% in solvents of disparate polarity. Comparison with the Förster critical distance suggests the terminals are ca. 18 Å apart. Time-resolved fluorescence spectroscopy, in conjunction with DFT calculations, indicates the dyad exists as a handful of conformers displaying a narrow range of EET rates. Optimisation of a distributive model allows accurate simulation of the EET dynamics in terms of reasonable structures based on isomerisation of certain amide groups.
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Affiliation(s)
- Sara M A Waly
- Molecular Photonics Laboratory, Bedson Building, School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
| | - Andrew C Benniston
- Molecular Photonics Laboratory, Bedson Building, School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
| | - Anthony Harriman
- Molecular Photonics Laboratory, Bedson Building, School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
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2
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Das S, Pal P, Ganguly T, Baitalik S. Influences of Both N,N,N- and N,N,C-Coordination Modes of Tolyl-terpyridine on the Photophysical Properties of Cyclometalated Ru(II) Complexes: Combined Experimental and Theoretical Investigations on Acid/Base-Dependent Reversible Cyclometalation. Inorg Chem 2023; 62:12872-12885. [PMID: 37506326 DOI: 10.1021/acs.inorgchem.3c01523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
With the goal of developing a new strategy for the synthesis of luminescent Ru(II) complexes, we have prepared herein a new set of bis-tridentate complexes of the type [(py-bpy-Ph-X)Ru(tpy-PhCH3)]ClO4 (X = -CH3, -CH2Br, and -CHO) incorporating both non-cyclometalated and cyclometalated coordination motifs of two isomeric forms of methylphenyl-terpyridine (tpy-PhCH3). Thorough characterization of the synthesized complexes is carried out using standard analytical tools and single crystal X-ray diffraction. Detailed investigations on their photophysical and electrochemical behaviors are carried out in MeCN. The presence of a carbanionic center in the cyclometalating unit increases the absorption spectral window of the complexes into a longer-wavelength region. The complexes also exhibit room-temperature luminescence in the NIR domain with enhanced excited-state lifetimes (up to 20.1 ns) compared to their non-cyclometalated counterpart, [Ru(tpy-PhCH3)2]2+. In the presence of acid, the non-coordinated nitrogen atom in the secondary coordination sphere of the complexes allows fine-tuning of the absorption and emission spectral properties. Excess acid induces de-coordination of the Ru-C bond, which is signaled by a remarkable alteration of their spectral profiles. Cleavage of the Ru-C bond is also possible upon treating the acidified solution of the complexes with visible light. Restoration of the Ru-C bond is again feasible upon treating the solution with base at an elevated temperature (∼70 °C). In essence, "on-off" and "off-on" switching of emission is facilitated upon alternating treatment of the Ru(II) complexes with acid, base, and temperature. DFT and TD-DFT calculations are also performed for assignments of the spectral bands as well as to understand structural changes associated with the switching behaviors of the complexes.
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Affiliation(s)
- Soumi Das
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
| | - Poulami Pal
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & B Raja S C Mullick Road, Kolkata 700032, India
| | - Tanusree Ganguly
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
| | - Sujoy Baitalik
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700032, India
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3
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Sell AC, Wetzel JC, Schmitz M, Maijenburg AW, Woltersdorf G, Naumann R, Kerzig C. Water-soluble ruthenium complex-pyrene dyads with extended triplet lifetimes for efficient energy transfer applications. Dalton Trans 2022; 51:10799-10808. [PMID: 35788236 DOI: 10.1039/d2dt01157c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Long triplet lifetimes of excited photosensitizers are essential for efficient energy transfer reactions in water, given that the concentrations of dissolved oxygen and suitable acceptors in aqueous media are typically much lower than in organic solvents. Herein, we report the design, synthesis and photochemical characterization of two structurally related water-soluble ruthenium complex-based dyads decorated with a covalently attached pyrene chromophore. The triplet energy of the latter is slightly below that of the metal complex enabling a so-called triplet reservoir and excited-state lifetime extensions of up to two orders of magnitude. The diimine co-ligands, which can be modified easily, have a major impact on both the ultrafast intramolecular energy transfer (iEnT) kinetics upon excitation with visible light and the lifetime of the resulting long-lived pyrene triplet. The phenanthroline-containing dyad shows fast triplet pyrene formation (25 ps) and an exceptionally long triplet lifetime beyond 50 microseconds in neat water. The iEnT process via the Dexter mechanism is slower by a factor of two when bipyridine co-ligands are employed, which is rationalized by a poor orbital overlap. Both dyads are very efficient sensitizers for the formation of singlet oxygen in air-saturated water as well as for the bimolecular generation of anthracene triplets that are key intermediates in upconversion mechanisms. This is demonstrated by the 5-hydroxymethylfurfural oxidation, which yields completely different main products depending on the pH value of the aqueous solution, as an initial application-related experiment and by time-resolved spectroscopy. Our findings are important in the greater contexts of photocatalysis and energy conversion in the "green" solvent water.
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Affiliation(s)
- Arne C Sell
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
| | - Julius C Wetzel
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
| | - Matthias Schmitz
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
| | - A Wouter Maijenburg
- Center for Innovation Competence SiLi-Nano, Martin-Luther-University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle, Germany
| | - Georg Woltersdorf
- Institute of Physics, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle, Germany
| | - Robert Naumann
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany. .,Center for Innovation Competence SiLi-Nano, Martin-Luther-University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Straße 3, 06120 Halle, Germany
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
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4
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Remarkably flexible 2,2′:6′,2″-terpyridines and their group 8–10 transition metal complexes – Chemistry and applications. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214426] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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5
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Esemoto NN, Satraitis A, Wiratan L, Ptaszek M. Symmetrical and Nonsymmetrical Meso-Meso Directly Linked Hydroporphyrin Dyads: Synthesis and Photochemical Properties. Inorg Chem 2018; 57:2977-2988. [PMID: 29140088 DOI: 10.1021/acs.inorgchem.7b02200] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A series of a rigid meso-meso directly linked chlorin-chlorin, chlorin-bacteriochlorin, and bacteriochlorin-bacteriochlorin dyads, including free bases as well as Zn(II), Pd(II), and Cu(II) complexes, has been synthesized, and their absorption, emission, singlet oxygen (1O2) photosensitization, and electronic properties have been examined. Marked bathochromic shifts of the long-wavelength Q y absorption band and increase in fluorescence quantum yields in dyads, in comparison to the corresponding monomers, are observed. Nonsymmetrical dyads (except bacteriochlorin-bacteriochlorin) show two distinctive Q y bands, corresponding to the absorption of each dyad component. A nearly quantitative S1-S1 energy transfer between hydroporphyrins in dyads, leading to an almost exclusive emission of hydroporphyrin with a lower S1 energy, has been determined. Several symmetrical and all nonsymmetrical dyads exhibit a significant reduction in fluorescence quantum yields in solvents of high dielectric constants; this is attributed to the photoinduced electron transfer. The complexation of one macrocycle by Cu(II) or Pd(II) enhances intersystem crossing in the adjacent, free base dyad component, which is manifested by a significant reduction in fluorescence and increase in quantum yield of 1O2 photosensitization.
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Affiliation(s)
- Nopondo N Esemoto
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
| | - Andrius Satraitis
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
| | - Linda Wiratan
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
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6
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Luo P, Karsenti PL, Marsan B, Harvey PD. Triplet energy vs. electron transfers in porphyrin- and tetrabenzoporphyrin-carboxylates/Pd3(dppm)3(CO)2+ cluster assemblies; a question of negative charge. NEW J CHEM 2018. [DOI: 10.1039/c7nj03943c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The simple replacement of the methyl groups by carboxylates changes the dominant quenching mechanism in dye⋯[Pd32+]x assemblies from energy to electron transfer.
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Affiliation(s)
- Peng Luo
- Département de chimie
- Université de Sherbrooke
- Sherbrooke
- Canada
| | | | - Benoit Marsan
- Département de chimie
- Université du Québec à Montréal
- Montréal
- Canada
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7
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Flamigni L. Functional Arrays for Light Energy Capture and Charge Separation. CHEM REC 2016; 16:1067-81. [DOI: 10.1002/tcr.201500295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Lucia Flamigni
- Istituto ISOF-CNR; Via P. Gobetti 101 40129 Bologna Italy
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8
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Lanzilotto A, Büldt LA, Schmidt HC, Prescimone A, Wenger OS, Constable EC, Housecroft CE. Improved light absorbance does not lead to better DSC performance: studies on a ruthenium porphyrin–terpyridine conjugate. RSC Adv 2016. [DOI: 10.1039/c5ra27397h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Despite having a good spectral response, a bis(tpy)ruthenium complex with peripheral porphyrin and phosphonate anchoring domains gives poor photoconversion efficiency due to a triplet–triplet energy transfer process.
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Affiliation(s)
| | - Laura A. Büldt
- Department of Chemistry
- University of Basel
- CH-4056 Basel
- Switzerland
| | - Hauke C. Schmidt
- Department of Chemistry
- University of Basel
- CH-4056 Basel
- Switzerland
| | | | - Oliver S. Wenger
- Department of Chemistry
- University of Basel
- CH-4056 Basel
- Switzerland
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9
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Quaranta A, Charalambidis G, Herrero C, Margiola S, Leibl W, Coutsolelos A, Aukauloo A. Synergistic "ping-pong" energy transfer for efficient light activation in a chromophore-catalyst dyad. Phys Chem Chem Phys 2015; 17:24166-72. [PMID: 26327298 DOI: 10.1039/c5cp04458h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The synthesis of a porphyrin-Ru(II) polypyridine complex where the porphyrin acts as a photoactive unit and the Ru(II) polypyridine as a catalytic precursor is described. Comparatively, the free base porphyrin was found to outperform the ruthenium based chromophore in the yield of light induced electron transfer. Mechanistic insights indicate the occurrence of a ping-pong energy transfer from the (1)LC excited state of the porphyrin chromophore to the (3)MCLT state of the catalyst and back to the (3)LC excited state of the porphyrin unit. The latter, triplet-triplet energy transfer back to the chromophore, efficiently competes with fast radiationless deactivation of the excited state at the catalyst site. The energy thus recovered by the chromophore allows improved yield of formation of the oxidized form of the chromophore and concomitantly of the oxidation of the catalytic unit by intramolecular charge transfer. The presented results are among the rare examples where a porphyrin chromophore is successfully used to drive an oxidative activation process where reductive processes prevail in the literature.
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Affiliation(s)
- Annamaria Quaranta
- Service de Bioénergétique, Biologie Structurale et Mécanismes (SB2SM), CEA, iBiTec-S, Biochimie Biophysique et Biologie Structurale (B3S), I2BC, UMR 9198, F-91191 Gif-sur-Yvette, France.
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10
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Langlois A, Xu HJ, Karsenti PL, Gros CP, Harvey PD. Very fast singlet and triplet energy transfers in a tri-chromophoric porphyrin dyad aided by the truxene platform. J PORPHYR PHTHALOCYA 2015. [DOI: 10.1142/s1088424615500327] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A trichromophoric dyad composed of an octa-β-alkyl-palladium(II)porphyrin (donor) and two tri-meso-aryl-zinc(II)porphyrins (acceptors) held by a truxene spacer exhibits very fast rates for triplet energy transfers at 77 (kET(T1) = 1.63 × 108 s-1) and 298 K (kET(T1) = 3.44 × 108 s-1), whereas the corresponding singlet energy transfer rates, kET(S1) = 3.9 × 1010 s-1 (77 K) and kET(S1) = 6.0 × 1010 s-1 (298 K), are also considered fast. The interpretation for these results is that the energy transfer processes proceed via a through bond Dexter mechanism (i.e. double electron exchange) supported by comparison with literature data and evidence for a moderate MO coupling between the donor and acceptor chromophores in the frontier MOs.
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Affiliation(s)
- Adam Langlois
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Hai-Jun Xu
- Université de Bourgogne, ICMUB (UMR 6302), 9, Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | | | - Claude P. Gros
- Université de Bourgogne, ICMUB (UMR 6302), 9, Avenue Alain Savary, BP 47870, 21078 Dijon Cedex, France
| | - Pierre D. Harvey
- Département de Chimie, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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11
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Kaur T, Khan TK, Ravikanth M. Multi-Expanded Porphyrin Assemblies on Cyclophosphazene Scaffolds. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Dey S, Mondal P, Rath SP. Aggregation-controlled excimer emission in an axial anthracene–Sn(iv)porphyrin–anthracene triad in the solid and solution phases. NEW J CHEM 2015. [DOI: 10.1039/c4nj02405b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An anthracene–porphyrin donor–acceptor triad has been synthesized and its photophysical properties along with excimer behavior are investigated.
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Affiliation(s)
- Soumyajit Dey
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
| | - Pritam Mondal
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
| | - Sankar Prasad Rath
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
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13
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Poddutoori PK, Lim GN, Vassiliev S, D'Souza F. Ultrafast charge separation and charge stabilization in axially linked ‘tetrathiafulvalene–aluminum(iii) porphyrin–gold(iii) porphyrin’ reaction center mimics. Phys Chem Chem Phys 2015; 17:26346-58. [DOI: 10.1039/c5cp04818d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sequential electron transfer leading to charge stabilization in newly synthesized vertically aligned ‘tetrathiafulvalene–aluminum(iii) porphyrin–gold(iii) porphyrin’ supramolecular triads is reported.
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Affiliation(s)
| | - Gary N. Lim
- Department of Chemistry
- University of North Texas
- Denton
- USA
| | - Serguei Vassiliev
- Department of Biological Sciences
- Brock University
- St. Catharines
- Canada
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14
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Filatov MA, Etzold F, Gehrig D, Laquai F, Busko D, Landfester K, Baluschev S. Interplay between singlet and triplet excited states in a conformationally locked donor–acceptor dyad. Dalton Trans 2015; 44:19207-17. [DOI: 10.1039/c5dt03784k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The synthesis and photophysical characterization of a palladium(ii) porphyrin – anthracene dyad bridged via short and conformationally rigid bicyclo[2.2.2]octadiene spacer were achieved.
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Affiliation(s)
- Mikhail A. Filatov
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
- Institute of Polymers
- Bulgarian Academy of Sciences
| | - Fabian Etzold
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | - Dominik Gehrig
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | - Frédéric Laquai
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
- Physical Sciences and Engineering Division (PSE)
- Material Science and Engineering (MSE)
| | - Dmitri Busko
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | | | - Stanislav Baluschev
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
- Optics and Spectroscopy Department
- Faculty of Physics
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15
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Kaur T, Rajeswararao M, Ravikanth M. Multiporphyrin Arrays on Cyclotriphosphazene Scaffolds. Inorg Chem 2014; 53:11051-9. [DOI: 10.1021/ic501569e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tejinder Kaur
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
| | | | - Mangalampalli Ravikanth
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
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16
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Di Valentin M, Tait CE, Salvadori E, Orian L, Polimeno A, Carbonera D. Evidence for water-mediated triplet–triplet energy transfer in the photoprotective site of the peridinin–chlorophyll a–protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:85-97. [DOI: 10.1016/j.bbabio.2013.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 11/15/2022]
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17
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Lee JR, Lung JW, Huang WL. Synthesis and Photophysical Properties of Hetero-Bischelated Complexes of Rhodium(III) Containing Phenyl-Pyridin-2-Ylmethylene-Amine. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200300033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Lee JR, Lung JW, Huang WL. Synthesis and Spectral Properties of Phenyl-Pyridin-2-Ylmethylene-Amine Complex of Rhodium(III). J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200200005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Poddutoori PK, Poddutoori P, Maiya BG. Synthesis, spectroscopy and photochemistry of dyads and triads with porphyrins and bis(terpyridine)ruthenium(II) complex. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424606000405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A bis(terpyridine)ruthenium(II) complex ([Ru]2+) was covalently connected via a floppy - OCH 2 CH 2 O - spacer to the free-base porphyrin (H) or zinc(II) porphyrin (Zn) or both, to obtain dyads ([HRu]2+, [ZnRu]2+) and triads ([HRuH]2+, [ZnRuH]2+, [ZnRuZn]2+). These compounds have been fully characterized by MALDI, UV-vis, 1 H NMR (1D and 1 H -1 H COSY) spectroscopies, and also by the cyclic and differential pulse voltammetric techniques. Absorption spectroscopy of these newly synthesized compounds shows that significant exciton coupling exists in non-polar solvents (cyclohexane and toluene) between the porphyrin ring and the bis(terpyridine)ruthenium(II) complex. Upon excitation within the Soret band of [HRu]2+/[HRuH]2+, free-base porphyrin fluorescence was found to be strongly quenched in non-polar and weakly quenched in polar solvents, probably due to ‘singlet-triplet’ energy transfer from the free-base porphyrin to the [Ru]2+ complex. Whereas, in [ZnRu]2+/[ZnRuZn]2+, zinc(II) porphyrin fluorescence was quantitatively and reasonably quenched in non-polar and polar solvents, respectively by mainly electron transfer from the zinc(II) porphyrin to the [Ru]2+ complex. The solvent plays a crucial role in the photophysical properties of these compounds, since the energy of the triplet metal-to-ligand charge-transfer (3MLCT) excited state is influenced by the polarity of the medium. Finally, [ZnRuH]2+ exhibits the combined fluorescence properties of [HRu]2+ and [ZnRu]2+ but the observed additional quenching in non-polar solvents for the zinc(II) porphyrin component is explained by energy transfer from the zinc(II) porphyrin to the free-base porphyrin and/or the bis(terpyridine)ruthenium(II) complex.
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Affiliation(s)
| | | | - Bhaskar G. Maiya
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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20
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Venanzi M, Tagliatesta P, Pastorini A, Mari P, Elisei F, Latterini L, Kadish KM. Perhalogenated porphyrins as a sink of excitation energy in porphyrin heterodimers. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424602000786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The photophysics of a new family of free-base and zinc derivatives of meso- tetraphenylporphyrin heterodimers have been studied by UV-vis absorption, fluorescence and nanosecond flash photolysis techniques. An almost complete (≈99%) and directionally controlled transfer of excitation energy from a donor porphyrin moiety was obtained by multiple bromination (four and eight Br substituents in the two series of compounds investigated) on the β-pyrrole positions of the acceptor porphyrin molecule. The covalently linked porphyrin dimers populate almost exclusively low energy triplet states because of the extremely efficient intramolecular singlet-to-triplet inter system crossing (ISC) process which is enhanced by the multiple heavy atoms substitutions. The nature of the electronic interactions determining the actual relaxation pathway followed by the porphyrin donor-acceptor pair is discussed.
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Affiliation(s)
- Mariano Venanzi
- Dipartimento di Scienze e Tecnologie Chimiche, Univ. Roma-Tor Vergata, 00133 Roma, Italy
| | - Pietro Tagliatesta
- Dipartimento di Scienze e Tecnologie Chimiche, Univ. Roma-Tor Vergata, 00133 Roma, Italy
| | - Alessandra Pastorini
- Dipartimento di Scienze e Tecnologie Chimiche, Univ. Roma-Tor Vergata, 00133 Roma, Italy
| | - Patrizia Mari
- Dipartimento di Scienze e Tecnologie Chimiche, Univ. Roma-Tor Vergata, 00133 Roma, Italy
| | - Fausto Elisei
- Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy
| | | | - Karl M. Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
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22
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Yoshikawa N, Yamabe S, Kanehisa N, Inoue T, Takashima H, Tsukahara K. The key Cl−
ligand for metal-to-ligand charge transfer in mononuclear terpyridine ruthenium(II) and binuclear ruthenium(II) tetrapyridylpyrazine complexes. J PHYS ORG CHEM 2011. [DOI: 10.1002/poc.1863] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- N. Yoshikawa
- Department of Chemistry, Faculty of Science; Nara Women's University; Nara 630-8506 Japan
| | - S. Yamabe
- Department of Chemistry; Nara University of Education; Nara 630-8528 Japan
| | - N. Kanehisa
- Division of Electrical, Electronic and Information Engineering; Osaka University; Osaka 565-0871 Japan
| | - T. Inoue
- Department of Applied Chemistry, Graduate School of Engineering; Osaka University; Osaka 565-0871 Japan
| | - H. Takashima
- Department of Chemistry, Faculty of Science; Nara Women's University; Nara 630-8506 Japan
| | - K. Tsukahara
- Department of Chemistry, Faculty of Science; Nara Women's University; Nara 630-8506 Japan
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23
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24
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Benniston AC, Harriman A, Li P. Bidirectional Electron Transfer in Molecular Tetrads. J Am Chem Soc 2009; 132:26-7. [DOI: 10.1021/ja908865k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew C. Benniston
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Anthony Harriman
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Peiyi Li
- Molecular Photonics Laboratory, School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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25
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Blumhoff J, Beckert R, Rau S, Losse S, Matschke M, Günther W, Görls H. Synthesis of Ligands Based on 4
H
‐Imidazoles and Pyridine Subunits: Selective Complexation and Bathochromically Absorbing Complexes. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200800914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jörg Blumhoff
- Institut für Organische und Makromolekulare Chemie der Friedrich‐Schiller‐Universität, Humboldtstr. 10, 07743 Jena, Germany, Fax: +49‐3641‐948212
| | - Rainer Beckert
- Institut für Organische und Makromolekulare Chemie der Friedrich‐Schiller‐Universität, Humboldtstr. 10, 07743 Jena, Germany, Fax: +49‐3641‐948212
| | - Sven Rau
- Institut für Anorganische und Allgemeine Chemie der Friedrich‐Alexander‐Universität, Erlangen Nürnberg Egerlandstraße 1, 91058 Erlangen, Germany
| | - Sebastian Losse
- Institut für Anorganische und Allgemeine Chemie der Friedrich‐Alexander‐Universität, Erlangen Nürnberg Egerlandstraße 1, 91058 Erlangen, Germany
| | - Martin Matschke
- Institut für Organische und Makromolekulare Chemie der Friedrich‐Schiller‐Universität, Humboldtstr. 10, 07743 Jena, Germany, Fax: +49‐3641‐948212
| | - Wolfgang Günther
- Institut für Organische und Makromolekulare Chemie der Friedrich‐Schiller‐Universität, Humboldtstr. 10, 07743 Jena, Germany, Fax: +49‐3641‐948212
| | - Helmar Görls
- Institut für Anorganische und Analytische Chemie der Friedrich‐Schiller‐Universität, Lessingstr. 8, 07743 Jena, Germany
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26
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Toma HE, Araki K. Exploring the Supramolecular Coordination Chemistry-Based Approach for Nanotechnology. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/9780470440124.ch5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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27
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Ventura B, Barigelletti F, Lodato F, Officer DL, Flamigni L. Energy transfer processes in electronically coupled porphyrin hetero-dyads connected at the β position. Phys Chem Chem Phys 2009; 11:2166-76. [DOI: 10.1039/b819138g] [Citation(s) in RCA: 13] [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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28
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Benniston AC, Harriman A, Pariani C, Sams CA. Competition between Energy Transfer and Interligand Electron Transfer in Porphyrin−Osmium(II) Bis(2,2‘:6‘,2‘ ‘-terpyridine) Dyads. J Phys Chem A 2007; 111:8918-24. [PMID: 17725331 DOI: 10.1021/jp0734326] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rapid intramolecular energy transfer occurs from a free-base porphyrin to an attached osmium(II) bis(2,2':6',2' '-terpyridine) complex, most likely by way of the Förster dipole-dipole mechanism. The initially formed metal-to-ligand, charge-transfer (MLCT) excited-singlet state localized on the metal complex undergoes very fast intersystem crossing to form the corresponding triplet excited state ((3)MLCT). This latter species transfers excitation energy to the (3)pi,pi* triplet state associated with the porphyrin moiety, such that the overall effect is to catalyze intersystem crossing for the porphyrin. Interligand electron transfer (ILET) to the distal terpyridine ligand, for which there is no driving force, competes poorly with triplet energy transfer from the proximal (3)MLCT to the porphyrin. Equipping the distal ligand with an ethynylene residue provides the necessary driving force for ILET and this process now competes effectively with triplet energy transfer to the porphyrin. The rate constants for all the relevant processes have been derived from laser flash photolysis studies.
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Affiliation(s)
- Andrew C Benniston
- Molecular Photonics Laboratory, School of Natural Sciences, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
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29
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Eng MP, Ljungdahl T, Andréasson J, Mårtensson J, Albinsson B. Triplet photophysics of gold(III) porphyrins. J Phys Chem A 2007; 109:1776-84. [PMID: 16833506 DOI: 10.1021/jp0449399] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Gold porphyrins are often used as electron-accepting chromophores in donor-acceptor complexes for the study of photoinduced electron transfer, and they can also be involved in triplet-triplet energy-transfer interactions with other chromophores. Since the lowest excited singlet state is very short-lived (240 fs), the triplet state is usually the starting point for the transfer reactions, and it is therefore crucial to understand its photophysics. The triplet state of various gold porphyrins has been reported to have a lifetime of around 1.5 ns at room temperature and to have a biexponential decay both in emission and in transient absorption with decay times of around 10 and 100 micros at 80 K. In this paper, the triplet photophysics of two gold porphyrins (Au(III) 5,15-bis(3,5-di-tert-butylphenyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin and Au(III) 5,10,15,20-tetra(3,5-di-tert-butylphenyl)porphyrin) are studied by steady-state and time-resolved absorption and emission spectroscopy over a wide temperature range (4-300 K). The study reveals the existence of a dark state with an approximate lifetime of 50 ns, which was not previously observed. This state acts as an intermediate between the short-lived singlet and the triplet state manifold. In addition, we present DFT calculations, in which the core electrons of the central metal were replaced by a pseudopotential to account for the relativistic effects, which suggest that the lowest excited singlet state is an optically forbidden ligand-to-metal charge-transfer (LMCT) state. This LMCT state is an obvious candidate for the experimentally observed dark state, and it is shown to dictate the photophysical properties of gold porphyrins by acting as a gate for triplet state formation versus direct return to the ground state.
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Affiliation(s)
- Mattias P Eng
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
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30
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Liu J, Huang JW, Fu B, Zhao P, Yu HC, Ji LN. Electronic and fluorescence spectral studies of a novel porphyrin-polypyridyl ruthenium(II) hybrid linked by a butyl chain. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2007; 67:391-4. [PMID: 16956785 DOI: 10.1016/j.saa.2006.07.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2006] [Revised: 07/14/2006] [Accepted: 07/19/2006] [Indexed: 05/11/2023]
Abstract
The electronic and fluorescence spectroscopic properties of a novel porphyrin-polypyridyl ruthenium(II) hybrid, [C(4)-TPP-(ip)Ru(phen)(2)](ClO(4))(2) (TPP=5,10,15,20-tetraphenylporphyrin, ip=imidazo[4,5-f][1,10]phenanthroline and phen=1,10-Phenanthroline), in which a polypyridyl ruthenium(II) moiety is linked to a porphyrin moiety by a butyl chain have been investigated and compared to its corresponding reference compounds. The studies of electronic absorption spectra have shown that there is an electronic interaction between the porphyrin moiety and the polypyridyl ruthenium(II) moiety in the hybrid. It can be found that intramolecular photoinduced electron and energy transfer processes may occur in the hybrid from the fluorescence spectra. When exciting in Soret band and Q band of porphyrin, the fluorescence quenching of the porphyrin moiety of the hybrid takes place due to electron transfer from the lowest singlet excited state (S(1)) to the appended polypyridyl rutherium(II) moiety, while the decay of S(2) (the second-excited singlet state) of the porphyrin moiety is mainly contributed to internal conversion to S(1). When exciting in MLCT band of the polypyridyl ruthenium(II) moiety, fluorescence corresponding to the polypyridyl ruthenium(II) moiety is quenched by intramolecular energy transfer from (3)MLCT of the ruthenium moiety to the lowest-energy triplet state localized on the porphyrin moiety.
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Affiliation(s)
- Jie Liu
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Optoelectronic Material and Technologies & School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China
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31
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Gupta I, Ravikanth M. Synthesis and photophysical studies of covalently linked porphyrin-21-thiaporphyrin dyads. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.09.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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32
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Benniston AC. Porphyrin linked poly(pyridyl)-based conjugates as artificial photosynthetic reaction centre models. Phys Chem Chem Phys 2007; 9:5739-47. [DOI: 10.1039/b708166a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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33
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Kon H, Tsuge K, Imamura T, Sasaki Y, Ishizaka S, Kitamura N. Structural, Redox, and Photophysical Studies of the Tetra(pyridyl)porphyrin Complex Containing Four (2,2‘-Bipyridine)(2,2‘:6‘,2‘ ‘-terpyridine)ruthenium(II) Groups. Inorg Chem 2006; 45:6875-83. [PMID: 16903745 DOI: 10.1021/ic0602852] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New hybrid complexes of polypyridyl ruthenium and pyridylporphyrins have been prepared by the coordination of pyridyl nitrogens to the ruthenium centers. A 1:4 hybrid complex, [{Ru(bpy)(trpy)}4(mu4-H2Py4P)]8+ ([1]8+) (bpy = 2,2'-bipyridine; trpy = 2,2':6',2"-terpyridine; H2Py4P = 5,10,15,20-tetra(4-pyridyl)porphyrin), has been characterized by the single-crystal X-ray diffraction method. A 1:1 complex, [{Ru(bpy)(trpy)}(H2PyT3P)]2+ ([2]2+) (H2PyT3P = 5-(4-pyridyl)tritolylporphyrin) has also been prepared. The Soret band of the porphyrin ring shifts to longer wavelength with some broadening, the extent of the shift being larger for [1]8+. Cyclic voltammograms of the two complexes show simple overlap of the component redox waves. The complexes are weakly emissive at room temperature, which becomes stronger at lower temperatures. While [1]8+ at >140 K and [2]2+ at 77-280 K show only porphyrin fluorescence, [1]8+ at <140 K shows ruthenium and porphyrin phosphorescence, in addition to the porphyrin fluorescence.
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Affiliation(s)
- Hiroki Kon
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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34
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Gabrielsson A, Hartl F, Zhang H, Lindsay Smith JR, Towrie M, Vlcek A, Perutz RN. Ultrafast charge separation in a photoreactive rhenium-appended porphyrin assembly monitored by picosecond transient infrared spectroscopy. J Am Chem Soc 2006; 128:4253-66. [PMID: 16569000 DOI: 10.1021/ja0539802] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rhenium(bipyridine)(tricarbonyl)(picoline) units have been linked covalently to tetraphenylmetalloporphyrins of magnesium and zinc via an amide bond between the bipyridine and one phenyl substituent of the porphyrin. The resulting complexes, abbreviated as [Re(CO)(3)(Pic)Bpy-MgTPP][OTf] and [Re(CO)(3)(Pic)Bpy-ZnTPP][OTf], exhibit no signs of electronic interaction between the Re(CO)(3)(bpy) units and the metalloporphyrin units in their ground states. However, emission spectroscopy reveals solvent-dependent quenching of porphyrin emission on irradiation into the long-wavelength absorption bands localized on the porphyrin. The characteristics of the excited states have been probed by picosecond time-resolved absorption (TRVIS) spectroscopy and time-resolved infrared (TRIR) spectroscopy in nitrile solvents. The presence of the charge-separated state involving electron transfer from MgTPP or ZnTPP to Re(bpy) is signaled in the TRIR spectra by a low-frequency shift in the nu(CO) bands of the Re(CO)(3) moiety similar to that observed by spectroelectrochemical reduction. Long-wavelength excitation of [Re(CO)(3)(Pic)Bpy-MTPP][OTf] results in characteristic TRVIS spectra of the S(1) state of the porphyrin that decay with a time constant of 17 ps (M = Mg) or 24 ps (M = Zn). The IR bands of the CS state appear on a time scale of less than 1 ps (Mg) or ca. 5 ps (Zn) and decay giving way to a vibrationally excited (i.e., hot) ground state via back electron transfer. The IR bands of the precursors recover with a time constant of 35 ps (Mg) or 55 ps (Zn). The short lifetimes of the charge-transfer states carry implications for the mechanism of reaction in the presence of triethylamine.
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Affiliation(s)
- Yoshiaki Kobuke
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916‐5 Takayama, Ikoma, Nara 630‐0192, Japan, Fax: +81‐743‐72‐6119
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36
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Eng MP, Ljungdahl T, Mårtensson J, Albinsson B. Triplet Excitation Energy Transfer in Porphyrin-Based Donor−Bridge−Acceptor Systems with Conjugated Bridges of Varying Length: An Experimental and DFT Study. J Phys Chem B 2006; 110:6483-91. [PMID: 16570945 DOI: 10.1021/jp056536u] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of donor--bridge--acceptor (D--B--A) systems with varying donor-acceptor distances have been studied with respect to their triplet energy transfer properties. The donor and acceptor moieties, zinc(II), and free-base porphyrin, respectively, were separated by 2-5 oligo-p-phenyleneethynylene units (OPE) giving rise to edge-to-edge separations ranging between 12.7 and 33.4 A. The study was performed in 2-MTHF at 150 K and it was established that triplet excitation energy transfer occurs with high efficiency in all of the studied D--B--A systems. The distance dependence was exponential with an attenuation factor, beta, equal to 0.45 +/- 0.015 A(-1). The experimental study was also supported by quantum mechanical DFT and TD-DFT calculations on a series of closely related model systems. A thorough analysis of the OPE-bridge conformational dynamics led to an equation that quantitatively models the distance dependence of the electronic coupling found in the experimental study.
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Affiliation(s)
- Mattias P Eng
- Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
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37
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Baranoff E, Barigelletti F, Bonnet S, Collin JP, Flamigni L, Mobian P, Sauvage JP. From Photoinduced Charge Separation to Light-driven Molecular Machines. PHOTOFUNCTIONAL TRANSITION METAL COMPLEXES 2006. [DOI: 10.1007/430_037] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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38
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Benniston AC, Harriman A, Pariani C, Sams CA. Intramolecular energy-transfer processes in a bis(porphyrin)-ruthenium(ii) bis(2,2′:6′,2″-terpyridine) molecular array. Phys Chem Chem Phys 2006; 8:2051-7. [PMID: 16633693 DOI: 10.1039/b600420b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A molecular triad has been synthesized comprising two free-base porphyrin terminals linked to a central ruthenium(II) bis(2,2':6',2''-terpyridine) subunit via meso-phenylene groups. Illumination into the ruthenium(II) complex is accompanied by rapid intramolecular energy transfer from the metal-to-ligand, charge-transfer (MLCT) triplet to the lowest-energy pi-pi* triplet state localized on one of the porphyrin subunits. Transfer takes place from a vibrationally excited level which lowers the activation energy. The electronic coupling matrix element for this process is 73 cm(-1). Selective illumination into the lowest-energy singlet excited state (S1) localized on the porphyrin leads to fast singlet-triplet energy transfer that populates the MLCT triplet state with high efficiency. This latter process occurs via Dexter-type electron exchange at room temperature, but the activation energy is high and the reaction is prohibited at low temperature. For this latter process, the electronic coupling matrix element is only 8 cm(-1).
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Affiliation(s)
- Andrew C Benniston
- Molecular Photonics Laboratory, School of Natural Sciences (Chemistry), University of Newcastle, Bedson Building, Newcastle upon Tyne, UK NE1 7RU.
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39
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Odobel F, Zabri H. Preparations and Characterizations of Bichromophoric Systems Composed of a Ruthenium Polypyridine Complex Connected to a Difluoroborazaindacene or a Zinc Phthalocyanine Chromophore. Inorg Chem 2005; 44:5600-11. [PMID: 16060609 DOI: 10.1021/ic050078m] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes the synthesis of a new series of molecules composed of a ruthenium cation liganded by a chloro or a thiocyanato, a 4,4'-(diethoxycarbonyl)-2,2'-bipyridine, and a 2,2':6',2' '-terpyridine substituted in its 4' position by a difluoroborazaindacene or a zinc phthalocyanine. A set of conditions are reported to conveniently synthesize these dyads by a Stille cross-coupling reaction between the trimethyltin derivative of the organic chromophore and the corresponding ruthenium complex with 4'-bromo-2,2':6',2' '-terpyridine and 4,4'-(diethoxycarbonyl)-2,2'-bipyridine. The dyads were studied by UV-visible absorption spectroscopy, steady-state fluorescence, and electrochemistry. The results of these studies indicate strong electronic coupling between the zinc phthalocyanine unit and the ruthenium complex but weakly electronically coupled systems in the case of dyads containing a difluoroborazaindacene unit. The new bichromophoric systems display strong absorbance in the visible spectrum. An efficient quenching of the fluorescence of the organic chromophore by the nearby ruthenium complex was also observed in all of the dyads. In dyads connected to the borazaindacene, excitation spectra indicate efficient photoinduced energy transfer from the borazaindacene to the ruthenium complex.
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Affiliation(s)
- Fabrice Odobel
- Laboratoire de Synthèse Organique, UMR CNRS 6513 and FR CNRS 2465, Faculté des Sciences et des Techniques de Nantes, France.
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40
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Santosh G, Ravikanth M. Rhenium(I) bridged porphyrin dyads with heteroatom substituted cores: Synthesis and fluorescence properties. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2005.03.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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41
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Synthesis, characterization and some properties of amide-linked porphyrin–ruthenium(II) tris(bipyridine) complexes. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.03.060] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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42
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Faure S, Stern C, Espinosa E, Douville J, Guilard R, Harvey PD. Triplet-Triplet Energy Transfer Controlled by the Donor-Acceptor Distance in Rigidly Held Palladium-Containing Cofacial Bisporphyrins. Chemistry 2005; 11:3469-81. [PMID: 15812878 DOI: 10.1002/chem.200400990] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eleven new complexes, including mono-, heterobi-, and homobimetallic cofacial bisporphyrins, (Pd)H2DPS, (M)H2DPX, (M)H2DPB, (PdZn)DPS, (PdZn)DPX, (Pt)2DPX, (M)2DPB (M = Pd, Pt), and (Pt)P (DPS4- = 4,6-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]dibenzothiophene tetraanion, DPX(4-) = 4,5-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]-9,9-dimethylxanthene tetraanion, DPB4- = 1,8-bis[5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrinyl)]biphenylene tetraanion, P2- = 5-phenyl-2,8,13,17-tetraethyl-3,7,12,18-tetramethylporphyrin dianion) have been synthesized and characterized. The photophysical properties of the donor (M)P (M=Pd or Pt, P=porphyrin chromophore) and the acceptor (free base H(2)P or (Zn)P) depend on the C(meso)-C(meso) distance and the presence of a heavy atom such as Pd(II) or Pt(II). The data were compared with those for the known compounds (Pd)2DPS, (Pd)2DPX, H4DPS, H4DPX, H4DPB, (Pd)P, (Zn)P, and H(2)P. The rate constants for triplet-triplet energy transfer (k(ET)) were measured for the heterobimetallic (PdZn) and monometallic [(M)H2] derivatives (M=Pd, Pt). The fluorescence lifetimes (Deltatau(F)) of the acceptors decrease as a result of the heavy-atom effect, and vary as follows: (Pd)H2DPS<<(Pd)H2DPX approximately (Pd)H2DPB. The k(ET) values calculated according to the equation k(ET)=(1/tau(emi)-1/tau(emi) (0)), where tau(emi) (0) is the emission lifetime of the homobimetallic bisporphyrins (no ET occurs), are equal to 0, 247+/-57 and 133+/-52 s(-1) for DPS, DPX, and DPB, respectively, in the (Pd)H(2) series. These measurements allowed the range of distance over which the Dexter mechanism for T(1)-T(1) energy transfer ceases to operate to be determined. This distance is somewhere between 4.3 and 6.3 A, in agreement with our recent findings on singlet-singlet energy transfer. During the course of this study, the X-ray crystal structure for (Pd)H2DPX was obtained; triclinic (P1), a = 11.1016(1), b = 14.9868(2), c = 20.6786(3) A, alpha = 102.091(1), beta = 100.587(1), gamma = 101.817(1) degrees , V = 3199.19(7) A(3), Z = 2.
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Affiliation(s)
- Sébastien Faure
- LIMSAG UMR 5633, Université de Bourgogne, 6 bd Gabriel, 21100 Dijon, France
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Benniston AC, Chapman GM, Harriman A, Mehrabi M. Intramolecular Energy Transfer in Molecular Dyads Comprising Free-base Porphyrin and Ruthenium(II) Bis(2,2‘:6‘,2‘ ‘-terpyridine) Termini. J Phys Chem A 2004. [DOI: 10.1021/jp047400j] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew C. Benniston
- Molecular Photonics Laboratory, School of Natural Sciences−Chemistry, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Glen M. Chapman
- Molecular Photonics Laboratory, School of Natural Sciences−Chemistry, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Anthony Harriman
- Molecular Photonics Laboratory, School of Natural Sciences−Chemistry, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Maryam Mehrabi
- Molecular Photonics Laboratory, School of Natural Sciences−Chemistry, Bedson Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
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Benniston AC, Chapman G, Harriman A, Mehrabi M, Sams CA. Electron Delocalization in a Ruthenium(II) Bis(2,2‘:6‘,2‘ ‘-terpyridyl) Complex. Inorg Chem 2004; 43:4227-33. [PMID: 15236534 DOI: 10.1021/ic035380e] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photophysical properties have been recorded for a ruthenium(II) bis(2,2':6',2' '-terpyridine) complex bearing a single ethynylene substituent. The target compound is weakly emissive in fluid solution at room temperature, but both the emission yield and lifetime increase dramatically as the temperature is lowered. As found for the unsubstituted parent complex, the full temperature dependence indicates that the lowest-energy triplet state couples to two higher-energy triplets and to the ground state. Luminescence occurs only from the lowest-energy triplet state, but the radiative and nonradiative decay rates indicate that electron delocalization occurs at the triplet level. Comparison of the target compound with the parent complex indicates that the ethynylene group reduces the size of the electron-vibrational coupling element for nonradiative decay of the lowest-energy triplet state. Although other factors are affected by substitution, this is by far the most important feature with regard to stabilization of the triplet state.
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Affiliation(s)
- Andrew C Benniston
- Molecular Photonics Laboratory, School of Natural Sciences (Chemistry), University of Newcastle, Newcastle upon Tyne, NE1 7RU United Kingdom
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Hofmeier H, Schubert US. Recent developments in the supramolecular chemistry of terpyridine–metal complexes. Chem Soc Rev 2004; 33:373-99. [PMID: 15280970 DOI: 10.1039/b400653b] [Citation(s) in RCA: 590] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This critical review describes recent developments in the field of supramolecular chemistry of terpyridine-metal complexes. The synthesis and characteristics of single as well as multiple homo- and heterometallic complexes is discussed. Furthermore, complexes containing fullerenes, biological building blocks, extended aggregates of different architectures as well as rings are presented. A special emphasis is placed upon the properties (e.g. redox properties, luminescence etc.) of functional systems. Potential applications in optical nano-devices, molecular storage units, molecular switches and solar cells are discussed.
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Affiliation(s)
- Harald Hofmeier
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute, The Netherlands
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Duati M, Tasca S, Lynch FC, Bohlen H, Vos JG, Stagni S, Ward MD. Enhancement of Luminescence Lifetimes of Mononuclear Ruthenium(II)−Terpyridine Complexes by Manipulation of the σ-Donor Strength of Ligands. Inorg Chem 2003; 42:8377-84. [PMID: 14658891 DOI: 10.1021/ic034691m] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and characterization of mixed ligand 2,2';6',2' '-terpyridine (tpy) ruthenium complexes with 2,6-bis([1,2,4]triazol-3-yl)pyridine, 2,6-bis(5-phenyl-[1,2,4]triazol-3-yl)pyridine, and 2,6-bis([1,2,3,4]tetrazol-5-yl)pyridine are reported. The species are characterized by HPLC, 1H NMR, UV/vis, and emission spectroscopy. The photophysical properties of the complexes are investigated as a function of temperature over the range 80-320 K. The emission lifetime observed for the fully deprotonated compounds at room temperature is about 80 ns. This increase by 2 orders of magnitude with respect to the parent "[Ru(tpy)2](2+)" complex is rationalized by an increase in the energy of the metal based dsigma orbital, rather than by manipulation of the pi* orbitals on the ligands. The acid-base and electrochemical properties of the compounds are reported also.
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Affiliation(s)
- Marco Duati
- National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin 9, Ireland
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48
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González-Cabello A, Vázquez P, Torres T, Guldi DM. Highly Coupled Dyads Based on Phthalocyanine−Ruthenium(II) Tris(bipyridine) Complexes. Synthesis and Photoinduced Processes. J Org Chem 2003; 68:8635-42. [PMID: 14575496 DOI: 10.1021/jo0341968] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new series of multicomponent ZnPc-Ru(bpy)(3) systems, 1a-c, consisting of a zinc-phthalocyanine linked through conjugated and/or nonconjugated connections to a ruthenium(II) tris(bipyridine) complex, has been synthesized. The ruthenium complexes 1a-c were prepared from phthalocyanines 2a-c, bearing a 4-substituted-2,2'-bipyridine ligand by treatment with [Ru(bpy)2Cl2].2H2O. Different synthetic strategies have been devised to prepare the corresponding dyad precursors (2a-c). Compound 2a, for example, with an ethenyl bridge, was synthesized by statistical condensation of 4-tert-butylphthalonitrile and 5-[(E)-2-(3,4-dicyanophenyl)ethenyl]-2,2'-bipyridine (3) in the presence of zinc chloride. Compounds 2b and 2c, having, respectively, an amide or an ethynyl bridge, were prepared following a different synthetic approach. The method involves the coupling of an appropriate 5-substituted-2,2'-bipyridine to an unsymmetrical phthalocyanine suitably functionalized with an amino (4) or an ethynyl group (5). The photophysical properties of the dyads that are ZnPc-Ru(bpy)3 1a-c and related model compounds have been determined by a variety of steady-state (i.e., fluorescence) and time-resolved methods (i.e., fluorescence and transient absorption). Clearly, intramolecular electronic interactions between the two subunits dominate the photophysical events following the initial excitation of either chromophore. These intramolecular interactions lead, in the case of photoexcited ZnPc, to faster intersystem crossing kinetics compared to a ZnPc reference, while photoexcited [Ru(bpy)3]2+) undergoes a rapid and efficient transduction of triplet excited-state energy to the Pc.
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Affiliation(s)
- Ana González-Cabello
- Departamento de Química Orgánica (C-I), Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid, Spain
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Andréasson J, Kodis G, Ljungdahl T, Moore AL, Moore TA, Gust D, Mårtensson J, Albinsson B. Photoinduced Hole Transfer from the Triplet State in a Porphyrin-Based Donor−Bridge−Acceptor System. J Phys Chem A 2003. [DOI: 10.1021/jp034120f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joakim Andréasson
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Gerdenis Kodis
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Thomas Ljungdahl
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Ana L. Moore
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Thomas A. Moore
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Devens Gust
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Jerker Mårtensson
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Bo Albinsson
- Department of Chemistry and Bioscience, Chalmers University of Technology, SE-412 96 Göteborg, Sweden, and Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
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Armaroli N. From metal complexes to fullerene arrays: exploring the exciting world of supramolecular photochemistry fifteen years after its birth. Photochem Photobiol Sci 2003; 2:73-87. [PMID: 12664965 DOI: 10.1039/b210569a] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
After over 15 years of extensive research work in many laboratories worldwide, supramolecular photochemistry is a well-established and highly recognized branch of science. A brief retrospective view on the birth and infancy of this research area is given and some of the latest developments are discussed. In supramolecular photochemistry Ru(II) and Cu(I) diimmine complexes and C60 fullerenes are some of the most widely investigated chromophores and over the years big efforts have been made to implement and tune their photophysical and excited state properties, which are briefly reviewed. Thanks to a huge amount of synthetic and analytical research work, it has been possible to insert or combine these organic and inorganic subunits in a variety of fascinating supramolecular architectures. Some results concerned with photoinduced processes occurring in dyads, triads, catenanes, rotaxanes, dendrimers, and protonated self-assembled architectures are briefly illustrated. The overall picture stemming form the current state of the art in supramolecular photochemistry is that of a discipline gaining an increasing degree of multidisciplinarity. Interconnections with biology, physics and information technology are being established at a very fast pace, suggesting a bright future for this still young research field.
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Affiliation(s)
- Nicola Armaroli
- Istituto per la Sintesi Organica e la Fotoreattività, Laboratorio di Fotochimica, Consiglio Nazionale delle Ricerche, via Gobetti 101, 40129 Bologna, Italy.
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