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Meares A, Yu Z, Viswanathan Bhagavathy G, Satraitis A, Ptaszek M. Photoisomerization of Enediynyl Linker Leads to Slipped Cofacial Hydroporphyrin Dyads with Strong Through-Bond and Through-Space Electronic Interactions. J Org Chem 2019; 84:7851-7862. [PMID: 31117562 DOI: 10.1021/acs.joc.9b00731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Photoisomerization of 3,4-di(methoxycarbonyl)-enediyne linker in hydroporphyrin (chlorin or bacteriochlorin) dyads leads to thermally stable cis isomers, where macrocycles adopt a slipped cofacial mutual geometry with an edge-to-edge distance of ∼3.6 Å (determined by density functional theory (DFT) calculations). Absorption spectra exhibit a significant splitting of the long-wavelength Qy band, which indicates a strong electronic coupling with a strength of V = ∼477 cm-1 that increases to 725 cm-1 upon metalation of hydroporphyrins. Each dyad features a broad, structureless emission band, with large Stokes shift, which is indicative of excimer formation. DFT calculations for dyads show both strong through-bond electronic coupling and through-space electronic interactions, due to the overlap of π-orbitals. Overall, geometry, electronic structure, strength of electronic interactions, and optical properties of reported dyads closely resemble those observed for photosynthetic special pairs. Dyads reported here represent a novel type of photoactive arrays with various modes of electronic interactions between chromophores. Combining through-bond and through-space coupling appears to be a viable strategy to engineer novel optical and photochemical properties in organic conjugated materials.
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Affiliation(s)
- Adam Meares
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
| | - Zhanqian Yu
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
| | - Ganga Viswanathan Bhagavathy
- 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
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry , University of Maryland, Baltimore County , 1000 Hilltop Circle , Baltimore , Maryland 21250 , United States
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McCleese C, Yu Z, Esemoto NN, Kolodziej C, Maiti B, Bhandari S, Dunietz BD, Burda C, Ptaszek M. Excitonic Interactions in Bacteriochlorin Homo-Dyads Enable Charge Transfer: A New Approach to the Artificial Photosynthetic Special Pair. J Phys Chem B 2018. [PMID: 29526105 DOI: 10.1021/acs.jpcb.8b02123] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Excitonically coupled bacteriochlorin (BC) dimers constitute a primary electron donor (special pair) in bacterial photosynthesis and absorbing units in light-harvesting antenna. However, the exact nature of the excited state of these dyads is still not fully understood. Here, we report a detailed spectroscopic and computational investigation of a series of symmetrical bacteriochlorin dimers, where the bacteriochlorins are connected either directly or by a phenylene bridge of variable length. The excited state of these dyads is quenched in high-dielectric solvents, which we attribute to photoinduced charge transfer. The mixing of charge transfer with the excitonic state causes accelerated (within 41 ps) decay of the excited state for the directly linked dyad, which is reduced by orders of magnitude with each additional phenyl ring separating the bacteriochlorins. These results highlight the origins of the excited-state dynamics in symmetric BC dyads and provide a new model for studying the primary processes in photosynthesis and for the development of artificial, biomimetic systems for solar energy conversion.
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Affiliation(s)
- Christopher McCleese
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Zhanqian Yu
- Department of Chemistry and Biochemistry , University of Maryland , Baltimore County, Baltimore , Maryland 21250 , United States
| | - Nopondo N Esemoto
- Department of Chemistry and Biochemistry , University of Maryland , Baltimore County, Baltimore , Maryland 21250 , United States
| | - Charles Kolodziej
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Buddhadev Maiti
- Department of Chemistry and Biochemistry , Kent State University , Kent , Ohio 44242 , United States
| | - Srijana Bhandari
- Department of Chemistry and Biochemistry , Kent State University , Kent , Ohio 44242 , United States
| | - Barry D Dunietz
- Department of Chemistry and Biochemistry , Kent State University , Kent , Ohio 44242 , United States
| | - Clemens Burda
- Department of Chemistry , Case Western Reserve University , Cleveland , Ohio 44106 , United States
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry , University of Maryland , Baltimore County, Baltimore , Maryland 21250 , United States
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Tamiaki H, Tanaka T, Wang XF. Photophysical properties of synthetic monomer, dimer, trimer, and tetramer of chlorophyll derivatives and their application to organic solar cells. J Photochem Photobiol A Chem 2015. [DOI: 10.1016/j.jphotochem.2015.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Khan AU, Kasha M. Mechanism of four-level laser action in solution excimer and excited-state proton-transfer cases. Proc Natl Acad Sci U S A 2010; 80:1767-70. [PMID: 16593295 PMCID: PMC393686 DOI: 10.1073/pnas.80.6.1767] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Four-level laser energy level schemes are compared from the mechanistic spectroscopic viewpoint: (i) noble-gas excimer, (ii) solution molecular excimer, (iii) conventional dye laser, and (iv) intramolecular proton transfer. The lasing action of the chlorophyll special pair is discussed as an example of a solution excimer laser, and the lasing action of 3-hydroxyflavone and other molecules is discussed as an example of an intramolecular proton-transfer laser.
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Affiliation(s)
- A U Khan
- Department of Chemistry and Institute of Molecular Biophysics, The Florida State University, Tallahassee, Florida 32306
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Nagata T. Synthesis and Characterization of Doubly-Strapped Porphyrins. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1992. [DOI: 10.1246/bcsj.65.385] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Yuen MJ, Shipmanj LL, Katz JJ, Hindman JC. ENERGY TRANSFER IN SELF-ASSEMBLED CHLOROPHYLL a SYSTEMS. Photochem Photobiol 1982. [DOI: 10.1111/j.1751-1097.1982.tb04366.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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