101
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Inokuma Y, Kwon JH, Ahn TK, Yoo MC, Kim D, Osuka A. Tribenzosubporphines: Synthesis and Characterization. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503426] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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102
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Huang TH, Chen YJ, Lo SS, Yen WN, Mai CL, Kuo MC, Yeh CY. Highly conjugated multiporphyrins: synthesis, spectroscopic and electrochemical properties. Dalton Trans 2006:2207-13. [PMID: 16673035 DOI: 10.1039/b516725f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of meso-to-meso ethynyl-bridged multiporphyrin arrays have been synthesized using Sonogoshira palladium-catalyzed cross-coupling reactions involving the appropriate ethynylporphyrin and iodoporphyrin precursors. The absorption spectra of these multiporphyrins show splitting of the Soret bands and significant red shifts of the Q bands as compared to the combination of the corresponding components. These conjugated multiporphyrins also show red shifts in their emission spectra as the pi-conjugation is expanded. In the electrochemical measurements, the porphyrins dimer 7 shows two 1 - e- oxidations at E(1/2) = +0.63 and +0.76 V for the first electron abstraction from the two porphyrin rings, indicating electronic communication between the two porphyrin units. The porphyrin trimer 4 exhibits the first and second 1 - e- oxidations at E(1/2) = +0.68 and +0.77 V, respectively, which correspond to the two outer porphyrins. The cyclic voltammogram of pentamer 5 shows two overlapping 1 - e- couples at E(1/2) = +0.56 and +0.66 V, and one 2 - e- couple at E(1/2) = +0.86 V, for the four outer porphyrin units. These results demonstrate that in the porphyrin trimer and pentamer the individual peripheral porphyrin units are electrochemically coupled via a central porphyrin core. The UV-Vis-NIR spectra of the oxidized species of these multiporphyrins exhibit a broad intervalence charge transfer (IVCT) band in the region from 1200 to 3000 nm. The present work shows that a central porphyrin unit appended with ethynyl bridges affords strong electronic interactions between the peripheral porphyrin rings over a distance of about 15 A.
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Affiliation(s)
- Teng-Hui Huang
- Department of Chemistry, Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung, Taiwan
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103
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Ceroni P, Bergamini G, Aubert N, Troiani V, Solladié N. A pentaporphyrin as a switching device activated by proton and redox stimuli. Chemphyschem 2005; 6:2120-8. [PMID: 16208754 DOI: 10.1002/cphc.200500173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A new pentaporphyrin array, constituted by a peptidic backbone and lateral chains with two free-base, one Mg(II), and two Zn(II) porphyrins, has been synthesized. The electrochemical and photophysical properties are not the mere superposition of those of its model compounds: slight shifts of the E(1/2) values and strong perturbation of both the Soret and Q-band absorption show substantial ground-state interactions among the component units, which take advantage of the rather flexible nature of the peptidic links. This multiporphyrin array, despite the flexible and nonconjugated nature of the peptidic spacers, plays the role of an antenna for visible light: an efficient photoinduced energy transfer takes place from the metalated porphyrin units to the free-base ones. Furthermore, the light emitted by the antenna can be: 1) tuned upon protonation of the free-base units, or 2) turned off by a redox input, since the formation of the Mg porphyrin radical cation, by either electrochemical or chemical methods, quenches the free-base porphyrin emission. Both quenching and tuning of the emission from the light-collecting center can be fully reverted by redox or chemical stimuli.
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Affiliation(s)
- Paola Ceroni
- Department of Chemistry G. Ciamician, Selmi 2, 40126 Bologna, Italy.
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104
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Bonifazi D, Accorsi G, Armaroli N, Song F, Palkar A, Echegoyen L, Scholl M, Seiler P, Jaun B, Diederich F. Oligoporphyrin Arrays Conjugated to [60]Fullerene: Preparation, NMR Analysis, and Photophysical and Electrochemical Properties. Helv Chim Acta 2005. [DOI: 10.1002/hlca.200590144] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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105
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Hwang IW, Park M, Ahn TK, Yoon ZS, Ko DM, Kim D, Ito F, Ishibashi Y, Khan SR, Nagasawa Y, Miyasaka H, Ikeda C, Takahashi R, Ogawa K, Satake A, Kobuke Y. Excitation-Energy Migration in Self-Assembled Cyclic Zinc(II)-Porphyrin Arrays: A Close Mimicry of a Natural Light-Harvesting System. Chemistry 2005; 11:3753-61. [PMID: 15827988 DOI: 10.1002/chem.200500069] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The excitation-energy-hopping (EEH) times within two-dimensional cyclic zinc(II)-porphyrin arrays 5 and 6, which were prepared by intermolecular coordination and ring-closing metathesis reaction of olefins, were deduced by modeling the EEH process based on the anisotropy depolarization as well as the exciton-exciton annihilation dynamics. Assuming the number of energy-hopping sites N = 5 and 6, the two different experimental observables, that is, anisotropy depolarization and exciton-excition annihilation times, consistently give the EEH times of 8.0 +/- 0.5 and 5.3 +/- 0.6 ps through the 1,3-phenylene linkages of 5 and 6, respectively. Accordingly, the self-assembled cyclic porphyrin arrays have proven to be well-defined two-dimensional models for natural light-harvesting complexes.
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Affiliation(s)
- In-Wook Hwang
- Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul, Korea
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106
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Aratani N, Takagi A, Yanagawa Y, Matsumoto T, Kawai T, Yoon ZS, Kim D, Osuka A. Giantmeso-meso-Linked Porphyrin Arrays of Micrometer Molecular Length and Their Fabrication. Chemistry 2005; 11:3389-404. [PMID: 15798970 DOI: 10.1002/chem.200401306] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
On the basis of the Ag(I)-promoted coupling reaction of zinc(II)-5,15-bis(3,5-dioctyloxyphenyl)porphyrin Z1, chain elongation has been attempted by using a stepwise doubling approach, which provides Z2, Z4, Z8, Z16, Z32, Z64, Z128, Z256, Z384, and Z512. The porphyrin arrays up to Z128 are sufficiently soluble in CHCl3 and THF despite their very long molecular lengths and rodlike structures, while the arrays over Z128 show a significant drop in solubility and stability. The discrete porphyrin arrays thus isolated were characterized by means of (1)H NMR spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, UV/Vis spectroscopy, gel-permeation chromatography (GPC), cyclic voltammetry (CV), single-crystal X-ray crystallography, scanning tunneling microscopy (STM), and atomic force microscopy (AFM). Contrary to expected linear conformations of the arrays Z n (where n is the number of porphyrins), the single molecular images of Z128, Z256, and Z512 revealed largely bent structures; this finding indicates the substantial conformational flexibility of Z n. We also exploited an effective synthetic route by means of which Z n can be fabricated with a thiol-protected aryl group to provide Z n S(2) through Z n Br(2), by bromination with N-bromosuccinimide and subsequent Pd-catalyzed Suzuki-Miyaura arylation. Finally, the reaction of Z256 provided Z512, Z768, and Z1024. Collectively, this work provides an important milestone in the preparation of sub-microscale discrete organic molecules and the fabrication of molecular-based materials, hence significantly contributing to device applications.
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Affiliation(s)
- Naoki Aratani
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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107
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Nakamura Y, Hwang IW, Aratani N, Ahn TK, Ko DM, Takagi A, Kawai T, Matsumoto T, Kim D, Osuka A. Directly meso-meso linked porphyrin rings: synthesis, characterization, and efficient excitation energy hopping. J Am Chem Soc 2005; 127:236-46. [PMID: 15631473 DOI: 10.1021/ja045254p] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Directly meso-meso linked porphyrin rings CZ4, CZ6, and CZ8 that respectively comprise four, six, and eight porphyrins have been synthesized in a stepwise manner from a 5,10-diaryl zinc(II) porphyrin building block. Symmetric cyclic structures have been indicated by their very simple (1)H NMR spectra that exhibit only a single set of porphyrin and their absorption spectra that display a characteristic broad nonsplit Soret band around 460 nm. Energy minimized structures calculated at the B3LYP/6-31G* level indicate that a dihedral angle between neighboring porphyrins decreases in order of CZ6 > CZ8 > CZ4, which is consistent with the (1)H NMR data. Photophysical properties of these molecules have been examined by the steady-state absorption, fluorescence, fluorescence lifetime, fluorescence anisotropy decay, and transient absorption measurements. Both the pump-power dependence on the femtosecond transient absorption and the transient absorption anisotropy decay profiles are directly related with the excitation energy migration processes within the porphyrin rings, where the exciton-exciton annihilation time and the polarization anisotropy rise time are well described in terms of the Forster-type incoherent energy hopping model. Consequently, the excitation energy hopping rates have been estimated for CZ4 (119 +/- 2 fs)(-)(1), CZ6 (342 +/- 59 fs)(-)(1), and CZ8 (236 +/- 31 fs)(-)(1), which reflect the magnitude of the electronic coupling between the neighboring porphyrins. Overall, these porphyrin rings serve as a well-defined wheel-shaped light harvesting antenna model in light of very efficient excitation energy hopping along the ring.
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Affiliation(s)
- Yasuyuki Nakamura
- Department of Chemistry, Graduate School of Science, Kyoto University, and Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Sakyo-ku, Kyoto 606-8502, Japan
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108
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Hwang IW, Ko DM, Ahn TK, Yoon ZS, Kim D, Peng X, Aratani N, Osuka A. Excitation Energy Migration in A Dodecameric Porphyrin Wheel. J Phys Chem B 2005; 109:8643-51. [PMID: 16852023 DOI: 10.1021/jp044274a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intramolecular excitation energy hopping (EEH) time within a dodecameric porphyrin wheel C6ZA, in which six meso-meso linked zinc(II) diporphyrin (Z2) subunits are bridged by 1,3-phenylene spacers, is deduced by a Förster energy hopping model based on S(1)-S(1) exciton-exciton annihilation and anisotropy depolarization. Under the assumption that the energy hopping sites are six Z2 subunits, two different observables (e.g., exciton-exciton annihilation and anisotropy depolarization times) consistently give the EEH time of 4.0 +/- 0.4 ps via 1,3-phenylene spacer of C6ZA, which is faster than 9.4 ps of linear 2Z2 (1,3-phenylene-linked zinc(II) tetraporphyrin). As a consequence, C6ZA serves as a well-defined two-dimensional model for a light-harvesting complex.
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Affiliation(s)
- In-Wook Hwang
- Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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109
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110
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Fujitsuka M, Hara M, Tojo S, Okada A, Troiani V, Solladié N, Majima T. Fast Exciton Migration in Porphyrin-Functionalized Polypeptides. J Phys Chem B 2004; 109:33-5. [PMID: 16850979 DOI: 10.1021/jp044866t] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photophysical properties of L-lysine-based polypeptides bearing porphyrin pendants were investigated. The intramolecular exciton-exciton annihilation resulting from the exciton migration among the porphyrin units deactivates the singlet excited state efficiently. It was revealed that the rate of the exciton migration depends on the polymerization degree.
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111
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Hwang IW, Kamada T, Ahn TK, Ko DM, Nakamura T, Tsuda A, Osuka A, Kim D. Porphyrin Boxes Constructed by Homochiral Self-Sorting Assembly: Optical Separation, Exciton Coupling, and Efficient Excitation Energy Migration. J Am Chem Soc 2004; 126:16187-98. [PMID: 15584755 DOI: 10.1021/ja046241e] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
meso-Pyridine-appended zinc(II) porphyrins Mn and their meso-meso-linked dimers Dn assemble spontaneously, in noncoordinating solvents such as CHCl3, into tetrameric porphyrin squares Sn and porphyrin boxes Bn, respectively. Interestingly, formation of Bn from Dn proceeds via homochiral self-sorting assembly, which has been verified by optical separations of B1 and B2. Optically pure enantiomers of B1 and B2 display strong Cotton effects in the CD spectra, which reflect the length of the pyridyl arm, thus providing evidence for the exciton coupling between the noncovalent neighboring porphyrin rings. Excitation energy migration processes within Bn have been investigated by steady-state and time-resolved spectroscopic methods in conjunction with polarization anisotropy measurements. Both the pump-power dependence on the femtosecond transient absorption and the transient absorption anisotropy decay profiles are directly associated with the excitation energy migration process within the Bn boxes, where the exciton-exciton annihilation time and the polarization anisotropy rise time are well described in terms of the Förster-type incoherent energy hopping model by assuming a number of hopping sites of N = 4 and an exciton coherence length of L = 2. Consequently, the excitation energy hopping rates between the zinc(II) diporphyrin units have been estimated for B1 (48 ps)(-1), B2 (98 +/- 3 ps)(-1), and B3 (361 +/- 6 ps)(-1). Overall, the self-assembled porphyrin boxes Bn serve as a well-defined three-dimensional model for the light-harvesting complex.
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Affiliation(s)
- In-Wook Hwang
- Center for Ultrafast Optical Characteristics Control and Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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112
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Fujitsuka M, Okada A, Tojo S, Takei F, Onitsuka K, Takahashi S, Majima T. Rapid Exciton Migration and Fluorescent Energy Transfer in Helical Polyisocyanides with Regularly Arranged Porphyrin Pendants. J Phys Chem B 2004. [DOI: 10.1021/jp047753i] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Ayumi Okada
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Sachiko Tojo
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Fumie Takei
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Kiyotaka Onitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Shigetoshi Takahashi
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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113
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Morandeira A, Vauthey E, Schuwey A, Gossauer A. Ultrafast Excited State Dynamics of Tri- and Hexaporphyrin Arrays. J Phys Chem A 2004. [DOI: 10.1021/jp049319m] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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114
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Peng X, Aratani N, Takagi A, Matsumoto T, Kawai T, Hwang IW, Ahn TK, Kim D, Osuka A. A dodecameric porphyrin wheel. J Am Chem Soc 2004; 126:4468-9. [PMID: 15070335 DOI: 10.1021/ja0392972] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A dodecameric porphyrin wheel was prepared by Ag(I)-promoted intramolecular coupling of a linear porphyrin dodecamer and was observed by scanning tunneling microscopy (STM). Efficient energy hopping along the array was revealed by femtosecond transient anisotropy measurements.
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Affiliation(s)
- Xiaobin Peng
- Department of Chemistry, Graduate School of Science, Kyoto University, Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Sakyo-ku, Kyoto 606-8502, Japan
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115
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Flamigni L, Talarico A, Ventura B, Marconi G, Sooambar C, Solladié N. Conformational Effects on the Photoinduced Energy Transfer in a Star-Shaped Pentaporphyrin with Nucleosidic Linkers. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300918] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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