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Siwawannapong K, Diers JR, Magdaong NCM, Nalaoh P, Kirmaier C, Lindsey JS, Holten D, Bocian DF. Extension of nature's NIR-I chromophore into the NIR-II region. Phys Chem Chem Phys 2024; 26:14228-14243. [PMID: 38690612 DOI: 10.1039/d4cp00779d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The development of chromophores that absorb in the near-infrared (NIR) region beyond 1000 nm underpins numerous applications in medical and energy sciences, yet also presents substantial challenges to molecular design and chemical synthesis. Here, the core bacteriochlorin chromophore of nature's NIR absorbers, bacteriochlorophylls, has been adapted and tailored by annulation in an effort to achieve absorption in the NIR-II region. The resulting bacteriochlorin, Phen2,1-BC, contains two annulated naphthalene groups spanning meso,β-positions of the bacteriochlorin and the 1,2-positions of the naphthalene. Phen2,1-BC was prepared via a new synthetic route. Phen2,1-BC is an isomer of previously examined Phen-BC, which differs only in attachment via the 1,8-positions of the naphthalene. Despite identical π-systems, the two bacteriochlorins have distinct spectroscopic and photophysical features. Phen-BC has long-wavelength absorption maximum (912 nm), oscillator strength (1.0), and S1 excited-state lifetime (150 ps) much different than Phen2,1-BC (1292 nm, 0.23, and 0.4 ps, respectively). These two molecules and an analogue with intermediate characteristics bearing annulated phenyl rings have unexpected properties relative to those of non-annulated counterparts. Understanding the distinctions requires extending concepts beyond the four-orbital-model description of tetrapyrrole spectroscopic features. In particular, a reduction in symmetry resulting from annulation results in electronic mixing of x- and y-polarized transitions/states, as well as vibronic coupling that together reduce oscillator strength of the long-wavelength absorption manifold and shorten the S1 excited-state lifetime. Collectively, the results suggest a heuristic for the molecular design of tetrapyrrole chromophores for deep penetration into the relatively unutilized NIR-II region.
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Affiliation(s)
| | - James R Diers
- Department of Chemistry, University of California, Riverside, CA, 92521-0403, USA.
| | | | | | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO, 63130-4889, USA.
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695-8204, USA.
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO, 63130-4889, USA.
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA, 92521-0403, USA.
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Faries KM, Hanson DK, Buhrmaster JC, Hippleheuser S, Tira GA, Wyllie RM, Kohout CE, Magdaong NCM, Holten D, Laible PD, Kirmaier C. Two pathways to understanding electron transfer in reaction centers from photosynthetic Bacteria: A comparison of Rhodobacter sphaeroides and Rhodobacter capsulatus mutants. Biochim Biophys Acta Bioenerg 2024:149047. [PMID: 38692451 DOI: 10.1016/j.bbabio.2024.149047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
The rates, yields, mechanisms and directionality of electron transfer (ET) are explored in twelve pairs of Rhodobacter (R.) sphaeroides and R. capsulatus mutant RCs designed to defeat ET from the excited primary donor (P*) to the A-side cofactors and re-direct ET to the normally inactive mirror-image B-side cofactors. In general, the R. sphaeroides variants have larger P+HB- yields (up to ~90 %) than their R. capsulatus analogs (up to ~60 %), where HB is the B-side bacteriopheophytin. Substitution of Tyr for Phe at L-polypeptide position L181 near BB primarily increases the contribution of fast P* → P+BB- → P+HB- two-step ET, where BB is the "bridging" B-side bacteriochlorophyll. The second step (~6-8 ps) is slower than the first (~3-4) ps, unlike A-side two-step ET (P* → P+BA- → P+HA-) where the second step (~1 ps) is faster than the first (~3-4 ps) in the native RC. Substitutions near HB, at L185 (Leu, Trp or Arg) and at M-polypeptide site M133/131 (Thr, Val or Glu), strongly affect the contribution of slower (20-50 ps) P* → P+HB- one-step superexchange ET. Both ET mechanisms are effective in directing electrons "the wrong way" to HB and both compete with internal conversion of P* to the ground state (~200 ps) and ET to the A-side cofactors. Collectively, the work demonstrates cooperative amino-acid control of rates, yields and mechanisms of ET in bacterial RCs and how A- vs. B-side charge separation can be tuned in both species.
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Affiliation(s)
- Kaitlyn M Faries
- Department of Chemistry, Washington University, St. Louis, MO 63130, United States of America
| | - Deborah K Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - James C Buhrmaster
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Stephen Hippleheuser
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Gregory A Tira
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Ryan M Wyllie
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Claire E Kohout
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, MO 63130, United States of America
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, United States of America
| | - Philip D Laible
- Biosciences Division, Argonne National Laboratory, Lemont, IL 60439, United States of America
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130, United States of America.
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Tran K, Faries K, Magdaong N, Kirmaier C, Holten D, Boxer SG. Application of amber suppression to study the role of Tyr M210 in electron transfer in R. sphaeroides photosynthetic reaction centers. Biophys J 2023; 122:57a. [PMID: 36784892 DOI: 10.1016/j.bpj.2022.11.516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Khoi Tran
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Kaitlyn Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Nikki Magdaong
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Chris Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Steven G Boxer
- Department of Chemistry, Stanford University, Stanford, CA, USA
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Jing H, Magdaong NCM, Diers JR, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Investigation of a bacteriochlorin-containing pentad array for panchromatic light-harvesting and charge separation. Phys Chem Chem Phys 2023; 25:1781-1798. [PMID: 36597966 DOI: 10.1039/d2cp05400k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A new pentad array designed to exhibit panchromatic absorption and charge separation has been synthesized and characterized. The array is composed of a triad panchromatic absorber (a bis(perylene-monoimide)-porphyrin) to which are appended an electron acceptor (perylene-diimide) and an electron donor/hole acceptor (bacteriochlorin) in a crossbar arrangement. The motivation for incorporation of the bacteriochlorin versus a free-base or zinc chlorin utilized in prior constructs was to facilitate hole transfer to this terminal unit and thereby achieve a higher yield of charge separation across the array. The intense S0 → S1 (Qy) band of the bacteriochlorin also enhances absorption in the near-infrared spectral region. Due to synthetic constraints, a phenylethyne linker was used to join the bacteriochlorin to the core porphyrin of the panchromatic triad rather than the diphenylethyne linker employed for the prior chlorin-containing pentads. Static and time-resolved photophysical studies reveal enhanced excited-state quenching for the pentad in benzonitrile and dimethyl sulfoxide compared to the prior chlorin-containing analogues. Success was only partial, however, as a long-lived charge separated state was not observed despite the improved energetics for the final ground-state hole/electron-shift reaction. The apparent reason is more facile competing charge-recombination due to the shorter bacteriochlorin - porphyrin linker that increases electronic coupling for this process. The studies highlight design criteria for balancing panchromatic absorption and long-lived charge separation in molecular architectures for solar-energy conversion.
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Affiliation(s)
- Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
| | | | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
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Jing H, Magdaong NCM, Diers JR, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Dyads with tunable near-infrared donor-acceptor excited-state energy gaps: molecular design and Förster analysis for ultrafast energy transfer. Phys Chem Chem Phys 2023; 25:1827-1847. [PMID: 36601996 DOI: 10.1039/d2cp04689j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Bacteriochlorophylls, nature's near-infrared absorbers, play an essential role in energy transfer in photosynthetic antennas and reaction centers. To probe energy-transfer processes akin to those in photosynthetic systems, nine synthetic bacteriochlorin-bacteriochlorin dyads have been prepared wherein the constituent pigments are joined at the meso-positions by a phenylethyne linker. The phenylethyne linker is an unsymmetric auxochrome, which differentially shifts the excited-state energies of the phenyl- or ethynyl-attached bacteriochlorin constituents in the dyad. Molecular designs utilized known effects of macrocycle substituents to engineer bacteriochlorins with S0 → S1 (Qy) transitions spanning 725-788 nm. The design-predicted donor-acceptor excited-state energy gaps in the dyads agree well with those obtained from time dependent density functional theory calculations and with the measured range of 197-1089 cm-1. Similar trends with donor-acceptor excited-state energy gaps are found for (1) the measured ultrafast energy-transfer rates of (0.3-1.7 ps)-1, (2) the spectral overlap integral (J) in Förster energy-transfer theory, and (3) donor-acceptor electronic mixing manifested in the natural transition orbitals for the S0 → S1 transition. Subtle outcomes include the near orthogonal orientation of the π-planes of the bacteriochlorin macrocycles, and the substituent-induced shift in transition-dipole moment from the typical coincidence with the NH-NH axis; the two features together afforded the Förster orientation term κ2 ranging from 0.55-1.53 across the nine dyads, a value supportive of efficient excited-state energy transfer. The molecular design and collective insights on the dyads are valuable for studies relevant to artificial photosynthesis and other processes requiring ultrafast energy transfer.
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Affiliation(s)
- Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
| | | | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA.
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA.
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
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6
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Roy A, Magdaong NCM, Jing H, Rong J, Diers JR, Kang HS, Niedzwiedzki DM, Taniguchi M, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Balancing Panchromatic Absorption and Multistep Charge Separation in a Compact Molecular Architecture. J Phys Chem A 2022; 126:9353-9365. [PMID: 36508586 DOI: 10.1021/acs.jpca.2c06040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A panchromatic triad and a charge-separation unit are joined in a crossbar architecture to capture solar energy. The panchromatic-absorber triad (T) is comprised of a central free-base porphyrin that is strongly coupled via direct ethyne linkages to two perylene-monoimide (PMI) groups. The charge-separation unit incorporates a free-base or zinc chlorin (C or ZnC) as a hole acceptor (or electron donor) and a perylene-diimide (PDI) as an electron acceptor, both attached to the porphyrin via diphenylethyne linkers. The free-base porphyrin is common to both light-harvesting and charge-separation motifs. The chlorin and PDI also function as ancillary light absorbers, complementing direct excitation of the panchromatic triad to produce the discrete lowest excited state of the array (T*). Attainment of full charge separation across the pentad entails two steps: (1) an initial excited-state hole/electron-transfer process to oxidize the chlorin (and reduce the panchromatic triad) or reduce the PDI (and oxidize the panchromatic triad); and (2) subsequent ground-state electron/hole migration to produce oxidized chlorin and reduced PDI. Full charge separation for pentad ZnC-T-PDI to generate ZnC+-T-PDI- occurs with a quantum yield of ∼30% and mean lifetime ∼1 μs in dimethyl sulfoxide. For C-T-PDI, initial charge separation is followed by rapid charge recombination. The molecular designs and studies reported here reveal the challenges of balancing the demands for charge separation (linker length and composition, excited-state energies, redox potentials, and medium polarity) with the constraints for panchromatic absorption (strong electronic coupling of the porphyrin and two PMI units) for integrated function in solar-energy conversion.
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Affiliation(s)
- Arpita Roy
- Department of Chemistry, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
| | - Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
| | - Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Jie Rong
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, Riverside, California 92521-0403, United States
| | - Hyun Suk Kang
- Department of Chemistry, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, and Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, St. Louis, Missouri 63130-4889, United States
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Magdaong NCM, Faries KM, Buhrmaster JC, Tira GA, Wyllie RM, Kohout CE, Hanson DK, Laible PD, Holten D, Kirmaier C. High Yield of B-Side Electron Transfer at 77 K in the Photosynthetic Reaction Center Protein from Rhodobacter sphaeroides. J Phys Chem B 2022; 126:8940-8956. [PMID: 36315401 DOI: 10.1021/acs.jpcb.2c05905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The primary electron transfer (ET) processes at 295 and 77 K are compared for the Rhodobacter sphaeroides reaction center (RC) pigment-protein complex from 13 mutants including a wild-type control. The engineered RCs bear mutations in the L and M polypeptides that largely inhibit ET from the excited state P* of the primary electron donor (P, a bacteriochlorophyll dimer) to the normally photoactive A-side cofactors and enhance ET to the C2-symmetry related, and normally photoinactive, B-side cofactors. P* decay is multiexponential at both temperatures and modeled as arising from subpopulations that differ in contributions of two-step ET (e.g., P* → P+BB- → P+HB-), one-step superexchange ET (e.g., P* → P+HB-), and P* → ground state. [HB and BB are monomeric bacteriopheophytin and bacteriochlorophyll, respectively.] The relative abundances of the subpopulations and the inherent rate constants of the P* decay routes vary with temperature. Regardless, ET to produce P+HB- is generally faster at 77 K than at 295 K by about a factor of 2. A key finding is that the yield of P+HB-, which ranges from ∼5% to ∼90% among the mutant RCs, is essentially the same at 77 K as at 295 K in each case. Overall, the results show that ET from P* to the B-side cofactors in these mutants does not require thermal activation and involves combinations of ET mechanisms analogous to those operative on the A side in the native RC.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - James C Buhrmaster
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Gregory A Tira
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Ryan M Wyllie
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Claire E Kohout
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Deborah K Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Philip D Laible
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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Liu R, Rong J, Wu Z, Taniguchi M, Bocian DF, Holten D, Lindsey JS. Panchromatic Absorbers Tethered for Bioconjugation or Surface Attachment. Molecules 2022; 27:molecules27196501. [PMID: 36235037 PMCID: PMC9573448 DOI: 10.3390/molecules27196501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/25/2022] [Accepted: 09/27/2022] [Indexed: 11/09/2022]
Abstract
The syntheses of two triads are reported. Each triad is composed of two perylene-monoimides linked to a porphyrin via an ethyne unit, which bridges the perylene 9-position and a porphyrin 5- or 15-position. Each triad also contains a single tether composed of an alkynoic acid or an isophthalate unit. Each triad provides panchromatic absorption (350–700 nm) with fluorescence emission in the near-infrared region (733 or 743 nm; fluorescence quantum yield ~0.2). The syntheses rely on the preparation of trans-AB-porphyrins bearing one site for tether attachment (A), an aryl group (B), and two open meso-positions. The AB-porphyrins were prepared by the condensation of a 1,9-diformyldipyrromethane and a dipyrromethane. The installation of the two perylene-monoimide groups was achieved upon the 5,15-dibromination of the porphyrin and the subsequent copper-free Sonogashira coupling, which was accomplished before or after the attachment of the tether. The syntheses provide relatively straightforward access to a panchromatic absorber for use in bioconjugation or surface-attachment processes.
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Affiliation(s)
- Rui Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Jie Rong
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Zhiyuan Wu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
- Correspondence: (D.F.B.); (D.H.); (J.S.L.); Tel.: +1-919-515-6406 (J.S.L.)
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889, USA
- Correspondence: (D.F.B.); (D.H.); (J.S.L.); Tel.: +1-919-515-6406 (J.S.L.)
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
- Correspondence: (D.F.B.); (D.H.); (J.S.L.); Tel.: +1-919-515-6406 (J.S.L.)
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Taniguchi M, Bocian DF, Holten D, Lindsey JS. Beyond green with synthetic chlorophylls – Connecting structural features with spectral properties. Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2022. [DOI: 10.1016/j.jphotochemrev.2022.100513] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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Magdaong NCM, Jing H, Diers JR, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Probing the Effects of Electronic-Vibrational Resonance on the Rate of Excited-State Energy Transfer in Bacteriochlorin Dyads. J Phys Chem Lett 2022; 13:7906-7910. [PMID: 35980198 DOI: 10.1021/acs.jpclett.2c02154] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The impact of vibrational-electronic resonances on the rate of excited-state energy transfer is examined in a set of bacteriochlorin dyads that employ the same phenylethyne linker. The donor/acceptor excited-state energy gap is tuned from ∼200 to ∼1100 cm-1 using peripheral substituents on the donor and acceptor bacteriochlorin macrocycles. Ultrafast energy transfer is observed with rate constants of (0.3 ps)-1 to (1.7 ps)-1, which agree with those predicted by Förster theory to within a factor of 2. Furthermore, the measured rates follow a trend-line with only small deviations that do not correlate with the density of vibrations at the donor/acceptor excited-state energy gap. Thus, if vibrational-electronic resonances occur in any of these dyads, which seems likely, the impact on the rate of energy transfer is small.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
| | - Haoyu Jing
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina27695-8204, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, Riverside, California92521-0403, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina27695-8204, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, Riverside, California92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri63130-4889, United States
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11
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Roy A, Diers JR, Niedzwiedzki DM, Meares A, Yu Z, Bhagavathy GV, Satraitis A, Kirmaier C, Ptaszek M, Bocian DF, Holten D. Photophysical Properties and Electronic Structure of Hydroporphyrin Dyads Exhibiting Strong Through-Space and Through-Bond Electronic Interactions. J Phys Chem A 2022; 126:5107-5125. [PMID: 35901315 DOI: 10.1021/acs.jpca.2c03114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Electronic interactions between tetrapyrroles are utilized in natural photosynthetic systems to tune the light-harvesting and energy-/charge-transfer processes in these assemblies. Such interactions also can be employed to tailor the electronic properties of tetrapyrrolic dyads and larger arrays for use in materials science and biomedical research. Here, we have utilized static and time-resolved optical spectroscopy to characterize the optical absorption and emission properties of a set of chlorin and bacteriochlorin dyads with varying degrees of through-bond (TB) and through-space (TS) interactions between the constituent macrocycles. The dyads consist of two chlorins or two bacteriochlorins joined by a linker that utilizes a triple-double-triple-bond (enediyne) motif in which the double-bond portion is an ester-substituted ethylene or o-phenylene unit. The photophysical studies are coupled with density functional theory (DFT) calculations to probe the ground-state molecular orbital (MO) characteristics of the dyads and time-dependent DFT calculations (TDDFT) to elucidate excited-state properties. The latter include electronic characteristics of the singlet excited-state manifold and the absorption transitions to these states from the electronic ground state. A comparison of the MO and calculated spectral properties of each dyad with the linker present versus disrupted (by eliminating the double-bond portion) gives insight into the relative contributions of TB versus TS interactions to the electronic properties of the dyads. The results show that the TB and TS contributions are additive (constructively interfere), which is not always the case for molecular dyads. Most of the dyads have shorter lifetimes of the lowest singlet excited state compared to the parent monomer, which derives from increased S1 → S0 internal conversion. The enhancement is greater for the dyads in benzonitrile than in toluene. The studies provide insights into the nature of the electronic interactions between the constituents in the tetrapyrrole arrays and how these interactions dictate the spectral properties and excited-state decay characteristics.
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Affiliation(s)
- Arpita Roy
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, and Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Adam Meares
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250-0001, United States
| | - Zhanqian Yu
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250-0001, United States
| | - Ganga Viswanathan Bhagavathy
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250-0001, United States
| | - Andrius Satraitis
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250-0001, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250-0001, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
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12
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Policht VR, Niedringhaus A, Willow R, Laible PD, Bocian DF, Kirmaier C, Holten D, Mančal T, Ogilvie JP. Hidden vibronic and excitonic structure and vibronic coherence transfer in the bacterial reaction center. Sci Adv 2022; 8:eabk0953. [PMID: 34985947 PMCID: PMC8730630 DOI: 10.1126/sciadv.abk0953] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report two-dimensional electronic spectroscopy (2DES) experiments on the bacterial reaction center (BRC) from purple bacteria, revealing hidden vibronic and excitonic structure. Through analysis of the coherent dynamics of the BRC, we identify multiple quasi-resonances between pigment vibrations and excitonic energy gaps, and vibronic coherence transfer processes that are typically neglected in standard models of photosynthetic energy transfer and charge separation. We support our assignment with control experiments on bacteriochlorophyll and simulations of the coherent dynamics using a reduced excitonic model of the BRC. We find that specific vibronic coherence processes can readily reveal weak exciton transitions. While the functional relevance of such processes is unclear, they provide a spectroscopic tool that uses vibrations as a window for observing excited state structure and dynamics elsewhere in the BRC via vibronic coupling. Vibronic coherence transfer reveals the upper exciton of the “special pair” that was weakly visible in previous 2DES experiments.
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Affiliation(s)
- Veronica R. Policht
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Andrew Niedringhaus
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Rhiannon Willow
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Tomáš Mančal
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic
| | - Jennifer P. Ogilvie
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
- Corresponding author.
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13
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Rong J, Magdaong NCM, Taniguchi M, Diers JR, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Electronic Structure and Excited-State Dynamics of Rylene-Tetrapyrrole Panchromatic Absorbers. J Phys Chem A 2021; 125:7900-7919. [PMID: 34472866 DOI: 10.1021/acs.jpca.1c05771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Panchromatic absorbers have potential applications in molecular-based energy-conversion schemes. A prior porphyrin-perylene dyad (P-PMI, where "MI" denotes monoimide) coupled via an ethyne linker exhibits panchromatic absorption (350-700 nm) and a tetrapyrrole-like lowest singlet excited state with a relatively long singlet excited-state lifetime (τS) and increased fluorescence quantum yield (Φf) versus the parent porphyrin. To explore the extension of panchromaticity to longer wavelengths, three arrays have been synthesized: a chlorin-terrylene dyad (C-TMI), a bacteriochlorin-terrylene dyad (B-TMI), and a perylene-porphyrin-terrylene triad (PMI-P-TMI), where the terrylene, a π-extended homologue of perylene, is attached via an ethyne linker. Characterization of the spectra (absorption and fluorescence), excited-state properties (lifetime, yields, and rate constants of decay pathways), and molecular-orbital characteristics reveals unexpected subtleties. The wavelength of the red-region absorption band increases in the order C-TMI (705 nm) < PMI-P-TMI (749 nm) < B-TMI (774 nm), yet each array exhibits diminished Φf and shortened τS values. The PMI-P-TMI triad in toluene exhibits Φf = 0.038 and τS = 139 ps versus the all-perylene triad (PMI-P-PMI) for which Φf = 0.26 and τS = 2000 ps. The results highlight design constraints for auxiliary pigments with tetrapyrroles to achieve panchromatic absorption with retention of viable excited-state properties.
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Affiliation(s)
- Jie Rong
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, and Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
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14
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Diers JR, Kirmaier C, Taniguchi M, Lindsey JS, Bocian DF, Holten D. A perspective on the redox properties of tetrapyrrole macrocycles. Phys Chem Chem Phys 2021; 23:19130-19140. [PMID: 34490865 DOI: 10.1039/d1cp01943k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tetrapyrrole macrocycles serve a multitude of roles in biological systems, including oxygen transport by heme and light harvesting and charge separation by chlorophylls and bacteriochlorophylls. Synthetic tetrapyrroles are utilized in diverse applications ranging from solar-energy conversion to photomedicine. Nevertheless, students beginning tetrapyrrole research, as well as established practitioners, are often puzzled when comparing properties of related tetrapyrroles. Questions arise as to why optical spectra of two tetrapyrroles often shift in wavelength/energy in a direction opposite to that predicted by common chemical intuition based on the size of a π-electron system. Gouterman's four-orbital model provides a framework for understanding these optical properties. Similarly, it can be puzzling as to why the oxidation potentials differ significantly when comparing two related tetrapyrroles, yet the reduction potentials change very little or shift in the opposite direction. In order to understand these redox properties, it must be recognized that structural/electronic alterations affect the four frontier molecular orbitals (HOMO, LUMO, HOMO-1 and LUMO+1) unequally and in many cases the LUMO+1, and not the LUMO, may track the HOMO in energy. This perspective presents a fundamental framework concerning tetrapyrrole electronic properties that should provide a foundation for rational molecular design in tetrapyrrole science.
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Affiliation(s)
- James R Diers
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889, USA.
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA 92521-0403, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889, USA.
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15
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Kang HS, Satraitis A, Meares A, Bhagavathy GV, Diers JR, Niedzwiedzki DM, Kirmaier C, Ptaszek M, Bocian DF, Holten D. Conjugated-linker dependence of the photophysical properties and electronic structure of chlorin dyads. J PORPHYR PHTHALOCYA 2021. [DOI: 10.1142/s1088424621500620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The synthesis, photophysical properties and electronic structure of seven new chlorin dyads and associated benchmark monomers are described. Each dyad contains two identical chlorins linked at the macrocycle [Formula: see text]-pyrrole 13-position. The extent of electronic communication between chlorin constituents depends on the nature of the conjugated linker. The communication is assessed by modification of prominent ground-state absorption and redox properties, rate constants and yields of excited-state decay processes, and molecular-orbital characteristics. Relative to the benchmark monomers, the chlorin dyads in toluene exhibit a substantial bathochromic shift of the long-wavelength absorption band (30 nm average), two-fold increased radiative rate constant [average (10 ns)[Formula: see text] vs. (22 ns)[Formula: see text]], reduced singlet excited-state lifetimes (average 5.0 ns vs. 8.2 ns), and increased fluorescence quantum yields (average 0.56 vs. 0.42). The excited-state lifetime and fluorescence yield for the chlorin dyad with a benzothiadiazole linker are reduced substantially in benzonitrile vs. toluene due largely to [Formula: see text]25-fold accelerated internal conversion. The results aid design strategies for molecular architectures that may find utility in solar-energy conversion and photomedicine.
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Affiliation(s)
- Hyun Suk Kang
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA
| | - Andrius Satraitis
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
| | - Adam Meares
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
| | - Ganga Viswanathan Bhagavathy
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
| | - James R. Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
| | - Dariusz M. Niedzwiedzki
- Center for Solar Energy and Energy Storage and Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO 63130-4889, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA
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16
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Magdaong NCM, Buhrmaster JC, Faries KM, Liu H, Tira GA, Lindsey JS, Hanson DK, Holten D, Laible PD, Kirmaier C. In Situ, Protein-Mediated Generation of a Photochemically Active Chlorophyll Analogue in a Mutant Bacterial Photosynthetic Reaction Center. Biochemistry 2021; 60:1260-1275. [PMID: 33835797 DOI: 10.1021/acs.biochem.1c00137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
All possible natural amino acids have been substituted for the native LeuL185 positioned near the B-side bacteriopheophytin (HB) in the bacterial reaction center (RC) from Rhodobacter sphaeroides. Additional mutations that enhance electron transfer to the normally inactive B-side cofactors are present. Approximately half of the isolated RCs with Glu at L185 contain a magnesium chlorin (CB) in place of HB. The chlorin is not the common BChl a oxidation product 3-desvinyl-3-acetyl chlorophyll a with a C-C bond in ring D and a C═C bond in ring B but has properties consistent with reversal of these bond orders, giving 17,18-didehydro BChl a. In such RCs, charge-separated state P+CB- forms in ∼5% yield. The other half of the GluL185-containing RCs have a bacteriochlorophyll a (BChl a) denoted βB in place of HB. Residues His, Asp, Asn, and Gln at L185 yield RCs with ≥85% βB in the HB site, while most other amino acids result in RCs that retain HB (≥95%). To the best of our knowledge, neither bacterial RCs that harbor five BChl a molecules and one chlorophyll analogue nor those with six BChl a molecules have been reported previously. The finding that altering the local environment within a cofactor binding site of a transmembrane complex leads to in situ generation of a photoactive chlorin with an unusual ring oxidation pattern suggests new strategies for amino acid control over pigment type at specific sites in photosynthetic proteins.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - James C Buhrmaster
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Haijun Liu
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Gregory A Tira
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Deborah K Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Philip D Laible
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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17
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Taniguchi M, Lindsey JS, Bocian DF, Holten D. Comprehensive review of photophysical parameters (ε, Φf, τs) of tetraphenylporphyrin (H2TPP) and zinc tetraphenylporphyrin (ZnTPP) – Critical benchmark molecules in photochemistry and photosynthesis. Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2021. [DOI: 10.1016/j.jphotochemrev.2020.100401] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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18
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Swainsbury DJK, Qian P, Jackson PJ, Faries KM, Niedzwiedzki DM, Martin EC, Farmer DA, Malone LA, Thompson RF, Ranson NA, Canniffe DP, Dickman MJ, Holten D, Kirmaier C, Hitchcock A, Hunter CN. Structures of Rhodopseudomonas palustris RC-LH1 complexes with open or closed quinone channels. Sci Adv 2021; 7:7/3/eabe2631. [PMID: 33523887 PMCID: PMC7806223 DOI: 10.1126/sciadv.abe2631] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/18/2020] [Indexed: 05/23/2023]
Abstract
The reaction-center light-harvesting complex 1 (RC-LH1) is the core photosynthetic component in purple phototrophic bacteria. We present two cryo-electron microscopy structures of RC-LH1 complexes from Rhodopseudomonas palustris A 2.65-Å resolution structure of the RC-LH114-W complex consists of an open 14-subunit LH1 ring surrounding the RC interrupted by protein-W, whereas the complex without protein-W at 2.80-Å resolution comprises an RC completely encircled by a closed, 16-subunit LH1 ring. Comparison of these structures provides insights into quinone dynamics within RC-LH1 complexes, including a previously unidentified conformational change upon quinone binding at the RC QB site, and the locations of accessory quinone binding sites that aid their delivery to the RC. The structurally unique protein-W prevents LH1 ring closure, creating a channel for accelerated quinone/quinol exchange.
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Affiliation(s)
- David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Pu Qian
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Philip J Jackson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - David A Farmer
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Lorna A Malone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Rebecca F Thompson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Daniel P Canniffe
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
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19
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Magdaong NCM, Taniguchi M, Diers JR, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Photophysical Properties and Electronic Structure of Zinc(II) Porphyrins Bearing 0-4 meso-Phenyl Substituents: Zinc Porphine to Zinc Tetraphenylporphyrin (ZnTPP). J Phys Chem A 2020; 124:7776-7794. [PMID: 32926787 DOI: 10.1021/acs.jpca.0c06841] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Six zinc(II) porphyrins bearing 0-4 meso-phenyl substituents have been examined spectroscopically and theoretically. Comparisons with previously examined free base analogues afford a deep understanding of the electronic and photophysical effects of systematic addition of phenyl groups in porphyrins containing a central zinc(II) ion versus two hydrogen atoms. Trends in the wavelengths and relative intensities of the absorption bands are generally consistent with predictions from time-dependent density functional theory calculations and simulations from Gouterman's four-orbital model. These trends derive from a preferential effect of the meso-phenyl groups to raise the energy of the highest occupied molecular orbital. The calculations reveal additional insights, such as a progressive increase in oscillator strength in the violet-red (B-Q) absorption manifold with increasing number of phenyls. Progressive addition of 0-4 phenyl substituents to the zinc porphyrins in O2-free toluene engenders a reduction in the measured lifetime of the lowest singlet excited state (2.5-2.1 ns), an increase in the S1 → S0 fluorescence yield (0.022-0.030), a decrease in the yield of S1 → T1 intersystem crossing (0.93-0.88), and an increase in the yield of S1 → S0 internal conversion (0.048-0.090). The derived rate constants for S1 decay reveal significant differences in the photophysical properties of the zinc chelates versus free base forms. The unexpected finding of a larger rate constant for internal conversion for zinc chelates versus free bases is particularly exemplary. Collectively, the findings afford fundamental insights into the photophysical properties and electronic structure of meso-phenylporphyrins, which are widely used as benchmarks for tetrapyrrole-based architectures in solar energy and life sciences research.
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Affiliation(s)
- Nikki Cecil M Magdaong
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - James R Diers
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University, St. Louis, Missouri 63130-4889, United States.,Department of Energy, Environment and Chemical Engineering, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
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20
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Faries KM, Kohout CE, Wang GX, Hanson DK, Holten D, Laible PD, Kirmaier C. Consequences of saturation mutagenesis of the protein ligand to the B-side monomeric bacteriochlorophyll in reaction centers from Rhodobacter capsulatus. Photosynth Res 2019; 141:273-290. [PMID: 30859455 DOI: 10.1007/s11120-019-00626-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
In bacterial reaction centers (RCs), photon-induced initial charge separation uses an A-side bacteriochlorophyll (BChl, BA) and bacteriopheophytin (BPh, HA), while the near-mirror image B-side BB and HB cofactors are inactive. Two new sets of Rhodobacter capsulatus RC mutants were designed, both bearing substitution of all amino acids for the native histidine M180 (M-polypeptide residue 180) ligand to the core Mg ion of BB. Residues are identified that largely result in retention of a BChl in the BB site (Asp, Ser, Pro, Gln, Asn, Gly, Cys, Lys, and Thr), ones that largely harbor the Mg-free BPh in the BB site (Leu and Ile), and ones for which isolated RCs are comprised of a substantial mixture of these two RC types (Ala, Glu, Val, Met and, in one set, Arg). No protein was isolated when M180 is Trp, Tyr, Phe, or (in one set) Arg. These findings are corroborated by ground state spectra, pigment extractions, ultrafast transient absorption studies, and the yields of B-side transmembrane charge separation. The changes in coordination chemistries did not reveal an RC with sufficiently precise poising of the redox properties of the BB-site cofactor to result in a high yield of B-side electron transfer to HB. Insights are gleaned into the amino acid properties that support BChl in the BB site and into the widely observed multi-exponential decay of the excited state of the primary electron donor. The results also have direct implications for tuning free energies of the charge-separated intermediates in RCs and mimetic systems.
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Affiliation(s)
- Kaitlyn M Faries
- Department of Chemistry, Washington University, St. Louis, MO, 63130, USA
| | - Claire E Kohout
- Biosciences Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Grace Xiyu Wang
- Biosciences Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Deborah K Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO, 63130, USA
| | - Philip D Laible
- Biosciences Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO, 63130, USA.
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21
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Wu Z, Fujita H, Magdaong NCM, Diers JR, Hood D, Allu S, Niedzwiedzki DM, Kirmaier C, Bocian DF, Holten D, Lindsey JS. New molecular design for blue BODIPYs. NEW J CHEM 2019. [DOI: 10.1039/c9nj01114e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Dihydro analogues of BODIPYs exhibit spectral features (Φf ∼ 0.4–0.9) resembling aminocoumarins and suggest applications for broad-band photosensitization or where large Stokes shifts are desired.
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Affiliation(s)
- Zhiyuan Wu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Hikaru Fujita
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | - James R. Diers
- Department of Chemistry
- University of California
- Riverside
- USA
| | - Don Hood
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | | | - Dariusz M. Niedzwiedzki
- Department of Energy
- Environmental & Chemical Engineering, and Center for Solar Energy and Energy Storage
- Washington University
- St. Louis
- USA
| | | | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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22
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Fujita H, Jing H, Krayer M, Allu S, Veeraraghavaiah G, Wu Z, Jiang J, Diers JR, Magdaong NCM, Mandal AK, Roy A, Niedzwiedzki DM, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Annulated bacteriochlorins for near-infrared photophysical studies. NEW J CHEM 2019. [DOI: 10.1039/c9nj01113g] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Bacteriochlorins with phenaleno or benzo annulation absorb at 913 or 1033 nm and exhibit excited-state lifetimes of 150 or 7 ps, suggesting applications in photoacoustic imaging.
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Affiliation(s)
- Hikaru Fujita
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Haoyu Jing
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Michael Krayer
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | | | - Zhiyuan Wu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Jianbing Jiang
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - James R. Diers
- Department of Chemistry
- University of California
- Riverside
- USA
| | | | - Amit K. Mandal
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | - Arpita Roy
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | - Dariusz M. Niedzwiedzki
- Department of Energy
- Environmental & Chemical Engineering and Center for Solar Energy and Energy Storage
- Washington University
- St. Louis
- USA
| | | | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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23
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Konar A, Sechrist R, Song Y, Policht VR, Laible PD, Bocian DF, Holten D, Kirmaier C, Ogilvie JP. Electronic Interactions in the Bacterial Reaction Center Revealed by Two-Color 2D Electronic Spectroscopy. J Phys Chem Lett 2018; 9:5219-5225. [PMID: 30136848 DOI: 10.1021/acs.jpclett.8b02394] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The bacterial reaction center (BRC) serves as an important model system for understanding the charge separation processes in photosynthesis. Knowledge of the electronic structure of the BRC is critical for understanding its charge separation mechanism. While it is well-accepted that the "special pair" pigments are strongly coupled, the degree of coupling among other BRC pigments has been thought to be relatively weak. Here we study the W(M250)V mutant BRC by two-color two-dimensional electronic spectroscopy to correlate changes in the Q x region with excitation of the Q y transitions. The resulting Q y-Q x cross-peaks provide a sensitive measure of the electronic interactions throughout the BRC pigment network and complement one-color 2D studies in which such interactions are often obscured by energy transfer and excited-state absorption signals. Our observations should motivate the refinement of electronic structure models of the BRC to facilitate improved understanding of the charge separation mechanism.
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Affiliation(s)
- Arkaprabha Konar
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Riley Sechrist
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Yin Song
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Veronica R Policht
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Philip D Laible
- Biosciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - David F Bocian
- Department of Chemistry , University of California , Riverside , California 92521 , United States
| | - Dewey Holten
- Department of Chemistry , Washington University , St. Louis , Missouri 63130 , United States
| | - Christine Kirmaier
- Department of Chemistry , Washington University , St. Louis , Missouri 63130 , United States
| | - Jennifer P Ogilvie
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
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24
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Yuen JM, Diers JR, Alexy EJ, Roy A, Mandal AK, Kang HS, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Origin of Panchromaticity in Multichromophore-Tetrapyrrole Arrays. J Phys Chem A 2018; 122:7181-7201. [PMID: 30152691 DOI: 10.1021/acs.jpca.8b06815] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Panchromatic absorbers that have robust photophysical properties enable new designs for molecular-based light-harvesting systems. Herein, we report experimental and theoretical studies of the spectral, redox, and excited-state properties of a series of perylene-monoimide-ethyne-porphyrin arrays wherein the number of perylene-monoimide units is stepped from one to four. In the arrays, a profound shift of absorption intensity from the strong violet-blue (B y and B x) bands of typical porphyrins into the green, red, and near-infrared (Q x and Q y) regions stems from mixing of chromophore and tetrapyrrole molecular orbitals (MOs), which gives multiplets of MOs having electron density spread over the entire array. This reduces the extensive mixing between porphyrin excited-state configurations and the transition-dipole addition and subtraction that normally leads to intense B and weak Q bands. Reduced configurational mixing derives from moderate effects of the ethyne and perylene on the MO energies and a more substantial effect of electron-density delocalization to reduce the configuration-interaction energy. Quantitative oscillator-strength analysis shows that porphyrin intensity is also shifted into the perylene-like green-region absorption and that the ethyne linkers lend absorption intensity. The reduced porphyrin configurational mixing also endows the S1 state with bacteriochlorin-like properties, including a 1-5 ns lifetime.
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Affiliation(s)
- Jonathan M Yuen
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - James R Diers
- Department of Chemistry , University of California , Riverside , California 92521-0403 , United States
| | - Eric J Alexy
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States
| | - Arpita Roy
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - Amit Kumar Mandal
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - Hyun Suk Kang
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - Dariusz M Niedzwiedzki
- Photosynthetic Antenna Research Center , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - Christine Kirmaier
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
| | - Jonathan S Lindsey
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695-8204 , United States
| | - David F Bocian
- Department of Chemistry , University of California , Riverside , California 92521-0403 , United States
| | - Dewey Holten
- Department of Chemistry , Washington University , St. Louis , Missouri 63130-4889 , United States
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25
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Tiwari V, Matutes YA, Konar A, Yu Z, Ptaszek M, Bocian DF, Holten D, Kirmaier C, Ogilvie JP. Strongly coupled bacteriochlorin dyad studied using phase-modulated fluorescence-detected two-dimensional electronic spectroscopy. Opt Express 2018; 26:22327-22341. [PMID: 30130927 DOI: 10.1364/oe.26.022327] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/30/2018] [Indexed: 05/27/2023]
Abstract
Fluorescence-detected two-dimensional electronic spectroscopy (F-2DES) projects the third-order non-linear polarization in a system as an excited electronic state population which is incoherently detected as fluorescence. Multiple variants of F-2DES have been developed. Here, we report phase-modulated F-2DES measurements on a strongly coupled symmetric bacteriochlorin dyad, a relevant 'toy' model for photosynthetic energy and charge transfer. Coherence map analysis shows that the strongest frequency observed in the dyad is well-separated from the excited state electronic energy gap, and is consistent with a vibrational frequency readily observed in bacteriochlorin monomers. Kinetic rate maps show a picosecond relaxation timescale between the excited states of the dyad. To our knowledge this is the first demonstration of coherence and kinetic analysis using the phase-modulation approach to F-2DES.
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26
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Hood D, Sahin T, Parkes‐Loach PS, Jiao J, Harris MA, Dilbeck P, Niedzwiedzki DM, Kirmaier C, Loach PA, Bocian DF, Lindsey JS, Holten D. Expanding Covalent Attachment Sites of Nonnative Chromophores to Encompass the C‐Terminal Hydrophilic Domain in Biohybrid Light‐Harvesting Architectures. CHEMPHOTOCHEM 2018. [DOI: 10.1002/cptc.201700182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Don Hood
- Department of Chemistry Washington University St. Louis MO 63130-4889 USA
| | - Tuba Sahin
- Department of Chemistry North Carolina State University Raleigh NC 27695-8204 USA
| | | | - Jieying Jiao
- Department of Chemistry University of California Riverside CA 92521-0403 USA
| | - Michelle A. Harris
- Department of Chemistry Washington University St. Louis MO 63130-4889 USA
| | - Preston Dilbeck
- Department of Chemistry Washington University St. Louis MO 63130-4889 USA
| | | | - Christine Kirmaier
- Department of Chemistry Washington University St. Louis MO 63130-4889 USA
| | - Paul A. Loach
- Department of Molecular Biosciences Northwestern University Evanston IL 60208-3500 USA
| | - David F. Bocian
- Department of Chemistry University of California Riverside CA 92521-0403 USA
| | - Jonathan S. Lindsey
- Department of Chemistry North Carolina State University Raleigh NC 27695-8204 USA
| | - Dewey Holten
- Department of Chemistry Washington University St. Louis MO 63130-4889 USA
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27
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Liu R, Liu M, Hood D, Chen CY, MacNevin CJ, Holten D, Lindsey JS. Chlorophyll-Inspired Red-Region Fluorophores: Building Block Synthesis and Studies in Aqueous Media. Molecules 2018; 23:molecules23010130. [PMID: 29320445 PMCID: PMC6017558 DOI: 10.3390/molecules23010130] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/04/2018] [Accepted: 01/06/2018] [Indexed: 02/04/2023] Open
Abstract
Fluorophores that absorb and emit in the red spectral region (600-700 nm) are of great interest in photochemistry and photomedicine. Eight new target chlorins (and 19 new chlorins altogether)-analogues of chlorophyll-of different polarities have been designed and synthesized for various applications; seven of the chlorins are equipped with a bioconjugatable tether. Hydrophobic or amphiphilic chlorins in a non-polar organic solvent (toluene), polar organic solvent (DMF), and aqueous or aqueous micellar media show a sharp emission band in the red region and modest fluorescence quantum yield (Φf = 0.2-0.3). A Poisson analysis implies most micelles are empty and few contain >1 chlorin. Water-soluble chlorins each bearing three PEG (oligoethyleneglycol) groups exhibit narrow emission bands (full-width-at-half maximum <25 nm). The lifetime of the lowest singlet excited state and the corresponding yields and rate constants for depopulation pathways (fluorescence, intersystem crossing, internal conversion) are generally little affected by the PEG groups or dissolution in aqueous or organic media. A set of chlorin-avidin conjugates revealed a 2-fold increase in Φf with increased average chlorin/avidin ratio (2.3-12). In summary, the chlorins of various polarities described herein are well suited as red-emitting fluorophores for applications in aqueous or organic media.
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Affiliation(s)
- Rui Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA; (R.L.); (M.L.)
| | - Mengran Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA; (R.L.); (M.L.)
| | - Don Hood
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889, USA;
| | - Chih-Yuan Chen
- NIRvana Sciences, Inc., Research Triangle Park, NC 27709, USA; (C.-Y.C.); (C.J.M.)
| | | | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889, USA;
- Correspondence: (D.H.); (J.S.L.); Tel.: +1-314-935-6502 (D.H.); +1-919-515-6406 (J.S.L.)
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA; (R.L.); (M.L.)
- Correspondence: (D.H.); (J.S.L.); Tel.: +1-314-935-6502 (D.H.); +1-919-515-6406 (J.S.L.)
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28
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Hu G, Kang HS, Mandal AK, Roy A, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Synthesis of arrays containing porphyrin, chlorin, and perylene-imide constituents for panchromatic light-harvesting and charge separation. RSC Adv 2018; 8:23854-23874. [PMID: 35540249 PMCID: PMC9081848 DOI: 10.1039/c8ra04052d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 06/15/2018] [Indexed: 12/14/2022] Open
Abstract
Achieving solar light harvesting followed by efficient charge separation and transport is an essential objective of molecular-based artificial photosynthesis. Architectures that afford strong absorption across the near-UV to near-infrared region, namely panchromatic absorptivity, are critically important given the broad spectral distribution of sunlight. A tetrapyrrole–perylene pentad array was synthesized and investigated as a means to integrate panchromatic light harvesting and intramolecular charge separation. The pentad consists of three moieties: (1) a panchromatically absorbing triad, in which a porphyrin is strongly coupled to two perylene-monoimides via ethyne linkages; (2) a perylene-diimide electron acceptor; and (3) a chlorin hole-trapping unit. Integrating the three components with diphenylethyne linkers generates moderate electronic coupling for intramolecular energy and hole/electron transfer. The construction of the array relies on a stepwise strategy for incorporating modular pigment building blocks. The key building blocks include a trans-A2BC porphyrin, a chlorin, a perylene-monoimide, and a perylene-diimide, each bearing appropriate (halo, ethynyl) synthetic handles for Pd-catalyzed Sonogashira coupling reactions. One target pentad, three tetrads, four triads, and four monomeric benchmark compounds were synthesized from six building blocks (three new, three reported) and 10 new synthetic intermediates. Four of the tetrapyrrole-containing arrays are zinc chelated, and four others are in the free base form. Absorption and fluorescence spectra and fluorescence quantum yields were also measured. Collectively, investigations of the arrays reveal insights into principles for the design of novel reaction centers integrated with a panchromatic antenna for artificial photosynthetic studies. Twelve arrays containing porphyrin, chlorin, and/or perylene-imide units were synthesized to investigate panchromatic absorption integrated with charge separation.![]()
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Affiliation(s)
- Gongfang Hu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Hyun Suk Kang
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | | | - Arpita Roy
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | | | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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29
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Mandal AK, Diers JR, Niedzwiedzki DM, Hu G, Liu R, Alexy EJ, Lindsey JS, Bocian DF, Holten D. Tailoring Panchromatic Absorption and Excited-State Dynamics of Tetrapyrrole–Chromophore (Bodipy, Rylene) Arrays—Interplay of Orbital Mixing and Configuration Interaction. J Am Chem Soc 2017; 139:17547-17564. [DOI: 10.1021/jacs.7b09548] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - James R. Diers
- Department
of Chemistry, University of California—Riverside, Riverside, California 92521-0403, United States
| | | | - Gongfang Hu
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Rui Liu
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Eric J. Alexy
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Jonathan S. Lindsey
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F. Bocian
- Department
of Chemistry, University of California—Riverside, Riverside, California 92521-0403, United States
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30
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Abstract
Attachment of synthetic analogs of natural tetrapyrroles to electroactive surfaces enables physicochemical interrogation and may provide material for use in catalysis, diagnostics, and energy conversion. Six synthetic zinc chlorins and one free base bacteriochlorin, tailored analogs of chlorophyll and bacteriochlorophyll, respectively, have been attached to Si(100) via a high-temperature (400°C) baking method. The hydroporphyrins bear diverse functional groups that enable surface attachment (vinyl, acetyl, triisopropylsilylethynyl, pentafluorophenyl, and hydroxymethylphenyl) and a geminal dimethyl group in each reduced ring for stabilization toward adventitious dehydrogenation. The films were examined by cyclic voltammetry, FTIR spectroscopy, X-ray photoelectron spectroscopy, and ellipsometry. Monofunctionalized and difunctionalized hydroporphyrins gave monolayer and multilayer films, respectively, indicating robustness of the hydroporphyrin molecules, but in each case the film was more heterogeneous than observed with comparable porphyrins. The data suggest that some amount of unattached molecules remain intercalated with surface-attached molecules. Additional molecular designs will need to be examined to develop a deep understanding of the structure-activity relationship for formation of homogeneous monolayers and multilayers of synthetic hydroporphyrins.
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Affiliation(s)
- Jieying Jiao
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
| | - Miao Yu
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, USA
| | - Jonathan S. Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, California 92521-0403, USA
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31
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Hood D, Niedzwiedzki DM, Zhang R, Zhang Y, Dai J, Miller ES, Bocian DF, Williams PG, Lindsey JS, Holten D. Photophysical Characterization of the Naturally Occurring Dioxobacteriochlorin Tolyporphin A and Synthetic Oxobacteriochlorin Analogues. Photochem Photobiol 2017; 93:1204-1215. [DOI: 10.1111/php.12781] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/04/2017] [Indexed: 01/21/2023]
Affiliation(s)
- Don Hood
- Department of Chemistry Washington University St. Louis MO
| | | | - Ran Zhang
- Department of Chemistry North Carolina State University Raleigh NC
| | - Yunlong Zhang
- Department of Chemistry North Carolina State University Raleigh NC
| | - Jingqiu Dai
- Department of Chemistry University of Hawaii at Manoa Honolulu HI
| | - Eric S. Miller
- Department of Plant and Microbial Biology North Carolina State University Raleigh NC
| | - David F. Bocian
- Department of Chemistry University of California Riverside CA
| | | | | | - Dewey Holten
- Department of Chemistry Washington University St. Louis MO
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32
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Faries KM, Dylla NP, Hanson DK, Holten D, Laible PD, Kirmaier C. Manipulating the Energetics and Rates of Electron Transfer in Rhodobacter capsulatus Reaction Centers with Asymmetric Pigment Content. J Phys Chem B 2017; 121:6989-7004. [DOI: 10.1021/acs.jpcb.7b01389] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kaitlyn M. Faries
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Nicholas P. Dylla
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Deborah K. Hanson
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Dewey Holten
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Christine Kirmaier
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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33
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Niedzwiedzki DM, Dilbeck PL, Tang Q, Martin EC, Bocian DF, Hunter CN, Holten D. New insights into the photochemistry of carotenoid spheroidenone in light-harvesting complex 2 from the purple bacterium Rhodobacter sphaeroides. Photosynth Res 2017; 131:291-304. [PMID: 27854005 PMCID: PMC5313593 DOI: 10.1007/s11120-016-0322-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 10/24/2016] [Indexed: 06/06/2023]
Abstract
Light-harvesting complex 2 (LH2) from the semi-aerobically grown purple phototrophic bacterium Rhodobacter sphaeroides was studied using optical (static and time-resolved) and resonance Raman spectroscopies. This antenna complex comprises bacteriochlorophyll (BChl) a and the carotenoid spheroidenone, a ketolated derivative of spheroidene. The results indicate that the spheroidenone-LH2 complex contains two spectral forms of the carotenoid: (1) a minor, "blue" form with an S2 (11B u+ ) spectral origin band at 522 nm, shifted from the position in organic media simply by the high polarizability of the binding site, and (2) the major, "red" form with the origin band at 562 nm that is associated with a pool of pigments that more strongly interact with protein residues, most likely via hydrogen bonding. Application of targeted modeling of excited-state decay pathways after carotenoid excitation suggests that the high (92%) carotenoid-to-BChl energy transfer efficiency in this LH2 system, relative to LH2 complexes binding carotenoids with comparable double-bond conjugation lengths, derives mainly from resonance energy transfer from spheroidenone S2 (11B u+ ) state to BChl a via the Qx state of the latter, accounting for 60% of the total transfer. The elevated S2 (11B u+ ) → Qx transfer efficiency is apparently associated with substantially decreased energy gap (increased spectral overlap) between the virtual S2 (11B u+ ) → S0 (11A g- ) carotenoid emission and Qx absorption of BChl a. This reduced energetic gap is the ultimate consequence of strong carotenoid-protein interactions, including the inferred hydrogen bonding.
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Affiliation(s)
- Dariusz M Niedzwiedzki
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA.
- Photosynthetic Antenna Research Center, Washington University in St. Louis, Campus Box 1138, St. Louis, MO, 63130, USA.
| | - Preston L Dilbeck
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Qun Tang
- Department of Chemistry, University of California Riverside, Riverside, CA, 92521, USA
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - David F Bocian
- Department of Chemistry, University of California Riverside, Riverside, CA, 92521, USA
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
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34
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Liu Y, Allu S, Nagarjuna Reddy M, Hood D, Diers JR, Bocian DF, Holten D, Lindsey JS. Synthesis and photophysical characterization of bacteriochlorins equipped with integral swallowtail substituents. NEW J CHEM 2017. [DOI: 10.1039/c7nj00499k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The two pyrroline units of bacteriochlorins can now bear gem-dialkyl or diaryl groups (L), which project above and below the macrocycle plane, whereas dimethyl groups generally have been accessible previously.
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Affiliation(s)
- Yizhou Liu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | | | - Don Hood
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | - James R. Diers
- Department of Chemistry
- University of California
- Riverside
- USA
| | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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35
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Liu M, Chen CY, Hood D, Taniguchi M, Diers JR, Bocian DF, Holten D, Lindsey JS. Synthesis, photophysics and electronic structure of oxobacteriochlorins. NEW J CHEM 2017. [DOI: 10.1039/c6nj04135c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthetic oxobacteriochlorins exhibit strong absorption in the deep-red window flanked by chlorins to the red and bacteriochlorins to the near-infrared.
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Affiliation(s)
- Mengran Liu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Chih-Yuan Chen
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Don Hood
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | | | - James R. Diers
- Department of Chemistry
- University of California
- Riverside
- USA
| | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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36
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Mandal AK, Taniguchi M, Diers JR, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Photophysical Properties and Electronic Structure of Porphyrins Bearing Zero to Four meso-Phenyl Substituents: New Insights into Seemingly Well Understood Tetrapyrroles. J Phys Chem A 2016; 120:9719-9731. [DOI: 10.1021/acs.jpca.6b09483] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amit Kumar Mandal
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Masahiko Taniguchi
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - James R. Diers
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dariusz M. Niedzwiedzki
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
- Photosynthetic
Antenna Research Center, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Christine Kirmaier
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S. Lindsey
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F. Bocian
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
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Amanpour J, Hu G, Alexy EJ, Mandal AK, Kang HS, Yuen JM, Diers JR, Bocian DF, Lindsey JS, Holten D. Tuning the Electronic Structure and Properties of Perylene-Porphyrin-Perylene Panchromatic Absorbers. J Phys Chem A 2016; 120:7434-50. [PMID: 27636001 DOI: 10.1021/acs.jpca.6b06857] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Light-harvesting architectures that afford strong absorption across the near-ultraviolet to near-infrared region, namely, panchromatic absorptivity, are potentially valuable for capturing the broad spectral distribution of sunlight. One previously reported triad consisting of two perylene monoimides strongly coupled to a free base porphyrin via ethyne linkers (FbT) shows panchromatic absorption together with a porphyrin-like S1 excited state albeit at lower energy than that of a typical monomeric porphyrin. Here, two new porphyrin-bis(perylene) triads have been prepared wherein the porphyrin bears two pentafluorophenyl substituents. The porphyrin is in the free base (FbT-F) or zinc chelate (ZnT-F) forms. The zinc chelate (ZnT) of the original triad bearing nonfluorinated aryl rings also was prepared. The triads were characterized using static and time-resolved optical spectroscopy. The results were analyzed with the aid of molecular-orbital characteristics obtained using density functional theory calculations. Of the four triads, FbT is the most panchromatic in affording the most even distribution of absorption spectral intensity as well as exhibiting the largest wavelength span (380-750 nm). The triads exhibit fluorescence yields (0.35 for FbT-F in toluene) that are substantially greater than for the porphyrin benchmarks (0.049 for FbP-F). The singlet excited-state lifetimes (τS) for the triads in toluene decrease in the order FbT-F (2.7 ns) > FbT (2.0 ns) > ZnT (1.2 ns) ∼ ZnT-F (1.1 ns). The τS values in benzonitrile are FbT (1.3 ns) > FbT-F (1.2 ns) > ZnT-F (0.6 ns) > ZnT (0.2 ns). Thus, the free base triads exhibit relatively long (1.2-2.7 ns) excited-state lifetimes in both polar and nonpolar media. The combined photophysical characteristics indicate that FbT and FbT-F are the best choices for panchromatic light-harvesting systems. Collectively, the findings afford insights into the effects of electronic structure on the panchromatic behavior of ethynyl-linked porphyrin-perylene architectures that can help guide next-generation designs and utilization of these systems.
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Affiliation(s)
- Javad Amanpour
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Gongfang Hu
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Eric J Alexy
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Amit Kumar Mandal
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - Hyun Suk Kang
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - Jonathan M Yuen
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - James R Diers
- Department of Chemistry, University of California , Riverside, California 92521-0403, United States
| | - David F Bocian
- Department of Chemistry, University of California , Riverside, California 92521-0403, United States
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695-8204, United States
| | - Dewey Holten
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
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Zhang N, Jiang J, Liu M, Taniguchi M, Mandal AK, Evans-Storms RB, Pitner JB, Bocian DF, Holten D, Lindsey JS. Bioconjugatable, PEGylated Hydroporphyrins for Photochemistry and Photomedicine. Narrow-Band, Near-Infrared-Emitting Bacteriochlorins. NEW J CHEM 2016; 40:7750-7767. [PMID: 28133433 DOI: 10.1039/c6nj01155a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Synthetic bacteriochlorins absorb in the near-infrared (NIR) region and are versatile analogues of natural bacteriochlorophylls. The utilization of these chromophores in energy sciences and photomedicine requires the ability to tailor their physicochemical properties, including the incorporation of units to impart water solubility. Herein, we report the synthesis, from two common bacteriochlorin building blocks, of five wavelength-tunable, bioconjugatable and water-soluble bacteriochlorins along with two non-bioconjugatable benchmarks. Each bacteriochlorin bears short polyethylene glycol (PEG) units as the water-solubilizing motif. The PEG groups are located at the 3,5-positions of aryl groups at the pyrrolic β-positions to suppress aggregation in aqueous media. A handle containing a single carboxylic acid is incorporated to allow bioconjugation. The seven water-soluble bacteriochlorins in water display Qy absorption into the NIR range (679-819 nm), sharp emission (21-36 nm full-width-at-half-maximum) and modest fluorescence quantum yield (0.017-0.13). Each bacteriochlorin is neutral (non-ionic) yet soluble in organic (e.g., CH2Cl2, DMF) and aqueous solutions. Water solubility was assessed using absorption spectroscopy by changing the concentration ∼1000-fold (190-690 µM to 0.19-0.69 µM) with a reciprocal change in pathlength (0.1-10 cm). All bacteriochlorins showed excellent solubility in water, except for a bacteriochlorin-imide that gave slight aggregation at higher concentrations. One bacteriochlorin was conjugated to a mouse polyclonal IgG antibody for use in flow cytometry with compensation beads for proof-of-principle. The antibody conjugate of B2-NHS displayed a sharp signal upon ultraviolet laser excitation (355 nm) with NIR emission measured with a 730/45 nm bandpass filter. Overall, the study gives access to a set of water-soluble bacteriochlorins with desirable photophysical properties for use in multiple fields.
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Affiliation(s)
- Nuonuo Zhang
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Jianbing Jiang
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Mengran Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Masahiko Taniguchi
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Amit Kumar Mandal
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | | | | | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA 92521-0403
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
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Liu M, Chen CY, Mandal AK, Chandrashaker V, Evans-Storms RB, Pitner JB, Bocian DF, Holten D, Lindsey JS. Bioconjugatable, PEGylated Hydroporphyrins for Photochemistry and Photomedicine. Narrow-Band, Red-Emitting Chlorins. NEW J CHEM 2016; 40:7721-7740. [PMID: 28154477 DOI: 10.1039/c6nj01154c] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chromophores that absorb and emit in the red spectral region (600-700 nm), are water soluble, and bear a bioconjugatable tether are relatively rare yet would fulfill many applications in photochemistry and photomedicine. Here, three molecular designs have been developed wherein stable synthetic chlorins - analogues of chlorophylls - have been tailored with PEG groups for use in aqueous solution. The designs differ with regard to order of the installation (pre/post-formation of the chlorin macrocycle) and position of the PEG groups. Six PEGylated synthetic chlorins (three free bases, three zinc chelates) have been prepared, of which four are equipped with a bioconjugatable (carboxylic acid) tether. The most effective design for aqueous solubilization entails facial encumbrance where PEG groups project above and below the plane of the hydrophobic disk-like chlorin macrocycle. The chlorins possess strong absorption at ~400 nm (B band) and in the red region (Qy band); regardless of wavelength of excitation, emission occurs in the red region. Excitation in the ~400 nm region thus provides an effective Stokes shift of >200 nm. The four bioconjugatable water-soluble chlorins exhibit Qy absorption/emission in water at 613/614, 636/638, 698/700 and 706/710 nm. The spectral properties are essentially unchanged in DMF and water for the facially encumbered chlorins, which also exhibit narrow Qy absorption and emission bands (full-width-at-half maximum of each <25 nm). The water-solubility was assessed by absorption spectroscopy over the concentration range ~0.4 μM - 0.4 mM. One chlorin was conjugated to a mouse polyclonal IgG antibody for use in flow cytometry with compensation beads for proof-of-principle. The conjugate displayed a sharp signal when excited by a violet laser (405 nm) with emission in the 620-660 nm range. Taken together, the designs described herein augur well for development of a set of spectrally distinct chlorins with relatively sharp bands in the red region.
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Affiliation(s)
- Mengran Liu
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Chih-Yuan Chen
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
| | - Amit Kumar Mandal
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | | | | | | | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA 92521-0403
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130-4889
| | - Jonathan S Lindsey
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204
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Dylla NP, Faries KM, Wyllie RM, Swenson AM, Hanson DK, Holten D, Kirmaier C, Laible PD. Species differences in unlocking B‐side electron transfer in bacterial reaction centers. FEBS Lett 2016; 590:2515-26. [DOI: 10.1002/1873-3468.12264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/13/2016] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Ryan M. Wyllie
- Biosciences Division Argonne National Laboratory Lemont IL USA
| | | | | | - Dewey Holten
- Department of Chemistry Washington University St. Louis MO USA
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Dilbeck PL, Tang Q, Mothersole DJ, Martin EC, Hunter CN, Bocian DF, Holten D, Niedzwiedzki DM. Quenching Capabilities of Long-Chain Carotenoids in Light-Harvesting-2 Complexes from Rhodobacter sphaeroides with an Engineered Carotenoid Synthesis Pathway. J Phys Chem B 2016; 120:5429-43. [PMID: 27285777 PMCID: PMC4921951 DOI: 10.1021/acs.jpcb.6b03305] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Six light-harvesting-2 complexes
(LH2) from genetically modified
strains of the purple photosynthetic bacterium Rhodobacter
(Rb.) sphaeroides were studied using static and ultrafast
optical methods and resonance Raman spectroscopy. These strains were
engineered to incorporate carotenoids for which the number of conjugated
groups (N = NC=C + NC=O) varies from 9 to 15.
The Rb. sphaeroides strains incorporate their native
carotenoids spheroidene (N = 10) and spheroidenone
(N = 11), as well as longer-chain analogues including
spirilloxanthin (N = 13) and diketospirilloxantion
(N = 15) normally found in Rhodospirillum
rubrum. Measurements of the properties of the carotenoid
first singlet excited state (S1) in antennas from the Rb. sphaeroides set show that carotenoid-bacteriochlorophyll a (BChl a) interactions are similar to
those in LH2 complexes from various other bacterial species and thus
are not significantly impacted by differences in polypeptide composition.
Instead, variations in carotenoid-to-BChl a energy
transfer are primarily regulated by the N-determined
energy of the carotenoid S1 excited state, which for long-chain
(N ≥ 13) carotenoids is not involved in energy
transfer. Furthermore, the role of the long-chain carotenoids switches
from a light-harvesting supporter (via energy transfer to BChl a) to a quencher of the BChl a S1 excited state B850*. This quenching is manifested as a substantial
(∼2-fold) reduction of the B850* lifetime and the B850* fluorescence
quantum yield for LH2 housing the longest carotenoids.
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Affiliation(s)
| | - Qun Tang
- Department of Chemistry, University of California Riverside , Riverside, California 92521, United States
| | - David J Mothersole
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
| | - David F Bocian
- Department of Chemistry, University of California Riverside , Riverside, California 92521, United States
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Faries KM, Kressel LL, Dylla NP, Wander MJ, Hanson DK, Holten D, Laible PD, Kirmaier C. Optimizing multi-step B-side charge separation in photosynthetic reaction centers from Rhodobacter capsulatus. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2016; 1857:150-159. [DOI: 10.1016/j.bbabio.2015.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/20/2015] [Accepted: 11/30/2015] [Indexed: 11/16/2022]
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Kang HS, Esemoto NN, Diers JR, Niedzwiedzki DM, Greco JA, Akhigbe J, Yu Z, Pancholi C, Bhagavathy GV, Nguyen JK, Kirmaier C, Birge RR, Ptaszek M, Holten D, Bocian DF. Effects of Strong Electronic Coupling in Chlorin and Bacteriochlorin Dyads. J Phys Chem A 2016; 120:379-95. [PMID: 26765839 DOI: 10.1021/acs.jpca.5b10686] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Achieving tunable, intense near-infrared absorption in molecular architectures with properties suitable for solar light harvesting and biomedical studies is of fundamental interest. Herein, we report the photophysical, redox, and molecular-orbital characteristics of nine hydroporphyrin dyads and associated benchmark monomers that have been designed and synthesized to attain enhanced light harvesting. Each dyad contains two identical hydroporphyrins (chlorin or bacteriochlorin) connected by a linker (ethynyl or butadiynyl) at the macrocycle β-pyrrole (3- or 13-) or meso (15-) positions. The strong electronic communication between constituent chromophores is indicated by the doubling of prominent absorption features, split redox waves, and paired linear combinations of frontier molecular orbitals. Relative to the benchmarks, the chlorin dyads in toluene show substantial bathochromic shifts of the long-wavelength absorption band (17-31 nm), modestly reduced singlet excited-state lifetimes (τS = 3.6-6.2 ns vs 8.8-12.3 ns), and increased fluorescence quantum yields (Φf = 0.37-0.57 vs 0.34-0.39). The bacteriochlorin dyads in toluene show significant bathochromic shifts (25-57 nm) and modestly reduced τS (1.6-3.4 ns vs 3.5-5.3 ns) and Φf (0.09-0.19 vs 0.17-0.21) values. The τS and Φf values for the bacteriochlorin dyads are reduced substantially (up to ∼20-fold) in benzonitrile. The quenching is due primarily to the increased S1 → S0 internal conversion that is likely induced by increased contribution of charge-resonance configurations to the S1 excited state in the polar medium. The fundamental insights gained into the physicochemical properties of the strongly coupled hydroporphyrin dyads may aid their utilization in solar-energy conversion and photomedicine.
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Affiliation(s)
- Hyun Suk Kang
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - Nopondo N Esemoto
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - James R Diers
- Department of Chemistry, University of California , Riverside, California 92521-0403, United States
| | - Dariusz M Niedzwiedzki
- Photosynthetic Antenna Research Center, Washington University , St. Louis, Missouri 63130-4889, United States
| | - Jordan A Greco
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3060, United States
| | - Joshua Akhigbe
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Zhanqian Yu
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Chirag Pancholi
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Ganga Viswanathan Bhagavathy
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Jamie K Nguyen
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Christine Kirmaier
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - Robert R Birge
- Department of Chemistry, University of Connecticut , Storrs, Connecticut 06269-3060, United States
| | - Marcin Ptaszek
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County , Baltimore, Maryland 21250-0001, United States
| | - Dewey Holten
- Department of Chemistry, Washington University , St. Louis, Missouri 63130-4889, United States
| | - David F Bocian
- Department of Chemistry, University of California , Riverside, California 92521-0403, United States
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Hu G, Liu R, Alexy EJ, Mandal AK, Bocian DF, Holten D, Lindsey JS. Panchromatic chromophore–tetrapyrrole light-harvesting arrays constructed from Bodipy, perylene, terrylene, porphyrin, chlorin, and bacteriochlorin building blocks. NEW J CHEM 2016. [DOI: 10.1039/c6nj01782g] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Five new chromophore–tetrapyrrole arrays bearing an ethynyl linker have been synthesized to explore the effects of chromophore nature and tetrapyrrole attachment site on panchromatic spectral properties.
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Affiliation(s)
- Gongfang Hu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Rui Liu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Eric J. Alexy
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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Zhang S, Kim HJ, Tang Q, Yang E, Bocian DF, Holten D, Lindsey JS. Synthesis and photophysical characteristics of 2,3,12,13-tetraalkylbacteriochlorins. NEW J CHEM 2016. [DOI: 10.1039/c6nj00517a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Tetraalkylbacteriochlorins, available upon acid-mediated self-condensation of α-ester stabilized dihydrodipyrrin-carboxaldehydes, provide valuable models of the naturally occurring bacteriochlorophylls.
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Affiliation(s)
- Shaofei Zhang
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Han-Je Kim
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
- Department of Science Education
| | - Qun Tang
- Department of Chemistry
- University of California
- Riverside
- USA
| | - Eunkyung Yang
- Department of Chemistry
- Washington University
- St. Louis
- USA
| | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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Mandal AK, Sahin T, Liu M, Lindsey JS, Bocian DF, Holten D. Photophysical comparisons of PEGylated porphyrins, chlorins and bacteriochlorins in water. NEW J CHEM 2016. [DOI: 10.1039/c6nj02091g] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Synthesis of a bioconjugatable water-soluble (PEGylated) trans-AB-porphyrin enables photophysical comparisons (τS, kf, kic, kisc, Φf, Φic, Φisc) with analogous chlorins and bacteriochlorins in DMF and water.
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Affiliation(s)
| | - Tuba Sahin
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | - Mengran Liu
- Department of Chemistry
- North Carolina State University
- Raleigh
- USA
| | | | | | - Dewey Holten
- Department of Chemistry
- Washington University
- St. Louis
- USA
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Yang E, Zhang N, Krayer M, Taniguchi M, Diers JR, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins. Photochem Photobiol 2015; 92:111-25. [PMID: 26505265 DOI: 10.1111/php.12547] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 10/02/2015] [Indexed: 12/19/2022]
Abstract
Understanding the effects of substituents on spectral properties is essential for the rational design of tailored bacteriochlorins for light-harvesting and other applications. Toward this goal, three new bacteriochlorins containing previously unexplored conjugating substituents have been prepared and characterized. The conjugating substituents include two positively charged species, 2-(N-ethyl 2-quinolinium)vinyl- (B-1) and 2-(N-ethyl 4-pyridinium)vinyl- (B-2), and a neutral group, acroleinyl- (B-3); the charged species resemble cyanine (or styryl) dye motifs whereas the neutral unit resembles a merocyanine dye motif. The three bacteriochlorins are examined by static and time-resolved absorption and emission spectroscopy and density functional theoretical calculations. B-1 and B-2 have Qy absorption bathochromically shifted well into the NIR region (822 and 852 nm), farther than B-3 (793 nm) and other 3,13-disubstituted bacteriochlorins studied previously. B-1 and B-2 have broad Qy absorption and fluorescence features with large peak separation (Stokes shift), low fluorescence yields, and shortened S1 (Qy ) excited-state lifetimes (~700 ps and ~100 ps). More typical spectra and S1 lifetime (~2.3 ns) are found for B-3. The combined photophysical and molecular-orbital characteristics suggest the altered spectra and enhanced nonradiative S1 decay of B-1 and B-2 derive from excited-state configurations in which electron density is shifted between the macrocycle and the substituents.
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Affiliation(s)
- Eunkyung Yang
- Department of Chemistry, Washington University, St. Louis, MO
| | - Nuonuo Zhang
- Department of Chemistry, North Carolina State University, Raleigh, NC
| | - Michael Krayer
- Department of Chemistry, North Carolina State University, Raleigh, NC
| | | | - James R Diers
- Department of Chemistry, University of California, Riverside, CA
| | | | | | - David F Bocian
- Department of Chemistry, University of California, Riverside, CA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO
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Sahin T, Harris MA, Vairaprakash P, Niedzwiedzki DM, Subramanian V, Shreve AP, Bocian DF, Holten D, Lindsey JS. Self-Assembled Light-Harvesting System from Chromophores in Lipid Vesicles. J Phys Chem B 2015; 119:10231-43. [PMID: 26230425 DOI: 10.1021/acs.jpcb.5b04841] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lipid vesicles are used as the organizational structure of self-assembled light-harvesting systems. Following analysis of 17 chromophores, six were selected for inclusion in vesicle-based antennas. The complementary absorption features of the chromophores span the near-ultraviolet, visible, and near-infrared region. Although the overall concentration of the pigments is low (~1 μM for quantitative spectroscopic studies) in a cuvette, the lipid-vesicle system affords high concentration (≥10 mM) in the bilayer for efficient energy flow from donor to acceptor. Energy transfer was characterized in 13 representative binary mixtures using static techniques (fluorescence-excitation versus absorptance spectra, quenching of donor fluorescence, modeling emission spectra of a mixture versus components) and time-resolved spectroscopy (fluorescence, ultrafast absorption). Binary donor-acceptor systems that employ a boron-dipyrrin donor (S0 ↔ S1 absorption/emission in the blue-green) and a chlorin or bacteriochlorin acceptor (S0 ↔ S1 absorption/emission in the red or near-infrared) have an average excitation-energy-transfer efficiency (ΦEET) of ~50%. Binary systems with a chlorin donor and a chlorin or bacteriochlorin acceptor have ΦEET ∼ 85%. The differences in ΦEET generally track the donor-fluorescence/acceptor-absorption spectral overlap within a dipole-dipole coupling (Förster) mechanism. Substantial deviation from single-exponential decay of the excited donor (due to the dispersion of donor-acceptor distances) is expected and observed. The time profiles and resulting ΦEET are modeled on the basis of (Förster) energy transfer between chromophores relatively densely packed in a two-dimensional compartment. Initial studies of two ternary and one quaternary combination of chromophores show the enhanced spectral coverage and energy-transfer efficacy expected on the basis of the binary systems. Collectively, this approach may provide one of the simplest designs for self-assembled light-harvesting systems that afford broad solar collection and efficient energy transfer.
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Affiliation(s)
- Tuba Sahin
- †Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Michelle A Harris
- ‡Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Pothiappan Vairaprakash
- †Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Dariusz M Niedzwiedzki
- §Photosynthetic Antenna Research Center, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Vijaya Subramanian
- ∥Center for Biomedical Engineering and Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
| | - Andrew P Shreve
- ∥Center for Biomedical Engineering and Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, New Mexico 87131-0001, United States
| | - David F Bocian
- ⊥Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- ‡Department of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S Lindsey
- †Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
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Niedzwiedzki DM, Dilbeck PL, Tang Q, Mothersole DJ, Martin EC, Bocian DF, Holten D, Hunter CN. Functional characteristics of spirilloxanthin and keto-bearing Analogues in light-harvesting LH2 complexes from Rhodobacter sphaeroides with a genetically modified carotenoid synthesis pathway. Biochim Biophys Acta 2015; 1847:640-55. [PMID: 25871644 DOI: 10.1016/j.bbabio.2015.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 04/01/2015] [Accepted: 04/03/2015] [Indexed: 11/24/2022]
Abstract
Light-harvesting 2 (LH2) complexes from a genetically modified strain of the purple photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were studied using static and ultrafast optical methods and resonance Raman spectroscopy. Carotenoid synthesis in the Rba. sphaeroides strain was engineered to redirect carotenoid production away from spheroidene into the spirilloxanthin synthesis pathway. The strain assembles LH2 antennas with substantial amounts of spirilloxanthin (total double-bond conjugation length N=13) if grown anaerobically and of keto-bearing long-chain analogs [2-ketoanhydrorhodovibrin (N=13), 2-ketospirilloxanthin (N=14) and 2,2'-diketospirilloxanthin (N=15)] if grown semi-aerobically (with ratios that depend on growth conditions). We present the photophysical, electronic, and vibrational properties of these carotenoids, both isolated in organic media and assembled within LH2 complexes. Measurements of excited-state energy transfer to the array of excitonically coupled bacteriochlorophyll a molecules (B850) show that the mean lifetime of the first singlet excited state (S1) of the long-chain (N≥13) carotenoids does not change appreciably between organic media and the protein environment. In each case, the S1 state appears to lie lower in energy than that of B850. The energy-transfer yield is ~0.4 in LH2 (from the strain grown aerobically or semi-aerobically), which is less than half that achieved for LH2 that contains short-chain (N≤11) analogues. Collectively, the results suggest that the S1 excited state of the long-chain (N≥13) carotenoids participates little if at all in carotenoid-to-BChl a energy transfer, which occurs predominantly via the carotenoid S2 excited state in these antennas.
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Affiliation(s)
- Dariusz M Niedzwiedzki
- Photosynthetic Antenna Research Center, Washington University, St. Louis, MO 63130, USA.
| | - Preston L Dilbeck
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Qun Tang
- Department of Chemistry, University of California Riverside, Riverside, CA 92521, USA
| | - David J Mothersole
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - David F Bocian
- Department of Chemistry, University of California Riverside, Riverside, CA 92521, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
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Vairaprakash P, Yang E, Sahin T, Taniguchi M, Krayer M, Diers JR, Wang A, Niedzwiedzki DM, Kirmaier C, Lindsey JS, Bocian DF, Holten D. Extending the Short and Long Wavelength Limits of Bacteriochlorin Near-Infrared Absorption via Dioxo- and Bisimide-Functionalization. J Phys Chem B 2015; 119:4382-95. [DOI: 10.1021/jp512818g] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Pothiappan Vairaprakash
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Eunkyung Yang
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Tuba Sahin
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Masahiko Taniguchi
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Michael Krayer
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - James R. Diers
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Alfred Wang
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Dariusz M. Niedzwiedzki
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
- Photosynthetic
Antenna Research Center, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Christine Kirmaier
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
| | - Jonathan S. Lindsey
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - David F. Bocian
- Department
of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Dewey Holten
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130-4889, United States
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