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Jonathan S Lindsey - One of the best experts on this subject based on the ideXlab platform.
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Bacteriochlorin bis spermine conjugate affords an effective photodynamic action to eradicate microorganisms
Journal of Biophotonics, 2020Co-Authors: Maria Belen Ballatore, Jonathan S Lindsey, Maria Elisa Milanesio, Hikaru Fujita, Edgardo N DurantiniAbstract:A novel Bacteriochlorin bearing two spermine units (BCS) was synthesized from 3,13-dibromo-8,8,18,18-tetramethylBacteriochlorin (BC-Br 3,13 ). The synthesis involved the Suzuki coupling of BC-Br 3,13 to obtain a Bacteriochlorin-dibenzaldehyde (BCA), which was subjected to reductive amination with spermine. The resulting Bacteriochlorin BCS presents a strong near-infrared absorption band at 747 nm, emits at 750 nm with fluorescence quantum yield of 0.14, and generates singlet molecular oxygen, O2 (1 Δg ), with a quantum yield of 0.27. Photokilling capacities mediated by BCS were evaluated in microbial cells. The viability of Staphylococcus aureus decreased 7 logs when cells were incubated with 1 μM BCS and irradiated for 15 minutes. Comparable photocytotoxic effect was obtained with Escherichia coli, when cells were treated for 30 minutes with visible light. BCS was also an effective photosensitizer to inactivate Candida albicans. In addition, this Bacteriochlorin was able to eradicate bacteria at short incubation times. The structure of BCS contains eight basic amino groups that, when protonated in water, increase the binding to the cell envelope. In summary, the readily accessible Bacteriochlorin BCS was highly effective at low concentrations as a broad-spectrum antimicrobial photosensitizer.
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Unusual Stability of a Bacteriochlorin Electrocatalyst under Reductive Conditions. A Case Study on CO2 Conversion to CO
2018Co-Authors: Jianbing Jiang, Jonathan S Lindsey, Adam J. Matula, John R. Swierk, Neyen Romano, Victor S. Batista, Robert H. Crabtree, Hailiang Wang, Gary W. BrudvigAbstract:Photosynthetic CO2 fixation is mediated by the enzyme RuBisCo, which employs a nonredox-active metal (Mg2+) to bind CO2 adjacent to an organic ligand that provides reducing equivalents for CO2 fixation. Attempts to use porphyrins as ligands in reductive catalysis have typically encountered severe stability issues owing to ligand reduction. Here, a synthetic zinc–Bacteriochlorin is reported as an effective and robust electrocatalyst for CO2 reduction to CO with an overpotential of 330 mV, without undergoing porphyrin-like ligand degradation (or demetalation) even after prolonged bulk electrolysis. The reaction has a CO Faradaic efficiency of 92% and sustains a total current density of 2.3 mA/cm2 at −1.9 V vs Ag/AgCl. DFT calculations highlight the molecular origin of the observed stability and provide insights into catalytic steps. This bioinspired study opens avenues for the application of Bacteriochlorin compounds for reductive electrocatalysis with extended life beyond that seen with porphyrin counterparts
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construction of the Bacteriochlorin macrocycle with concomitant nazarov cyclization to form the annulated isocyclic ring analogues of bacteriochlorophyll a
Journal of Organic Chemistry, 2017Co-Authors: Shaofei Zhang, Jonathan S LindseyAbstract:Bacteriochlorophylls contain a Bacteriochlorin macrocycle bearing an annulated fifth ring. The fifth ring, termed the isocyclic ring or ring E, is equipped with 131-oxo and 132-carbomethoxy substituents. Herein, a general route to stable, synthetic bacteriochlorophyll analogues is described. Knoevenagel condensation (∼40 mM, rt, CH2Cl2, piperidine/AcOH/molecular sieves) of a dihydrodipyrrin–carboxaldehyde (AD half) and a dihydrodipyrrin substituted with a β-ketoester (BC half) forms a propenone bearing the two halves (a hydrobilin analogue). Subsequent treatment (0.2 mM) with acid (Yb(OTf)3, CH3CN, 80 °C) promotes a double ring-closure process: (i) condensation between the α-position of pyrrole ring A and the α-acetal unit attached to pyrroline ring B forms the Bacteriochlorin macrocycle, and (ii) Nazarov cyclization of the β-(propenoyl)-substituted ring C forms the isocyclic ring (E). Five new Bacteriochlorins bearing various substituents (alkyl/alkyl, aryl, and alkyl/ester) at positions 2 and 3 (β-pyrro...
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Construction of the Bacteriochlorin Macrocycle with Concomitant Nazarov Cyclization To Form the Annulated Isocyclic Ring: Analogues of Bacteriochlorophyll a
2017Co-Authors: Shaofei Zhang, Jonathan S LindseyAbstract:Bacteriochlorophylls contain a Bacteriochlorin macrocycle bearing an annulated fifth ring. The fifth ring, termed the isocyclic ring or ring E, is equipped with 131-oxo and 132-carbomethoxy substituents. Herein, a general route to stable, synthetic bacteriochlorophyll analogues is described. Knoevenagel condensation (∼40 mM, rt, CH2Cl2, piperidine/AcOH/molecular sieves) of a dihydrodipyrrin–carboxaldehyde (AD half) and a dihydrodipyrrin substituted with a β-ketoester (BC half) forms a propenone bearing the two halves (a hydrobilin analogue). Subsequent treatment (0.2 mM) with acid (Yb(OTf)3, CH3CN, 80 °C) promotes a double ring-closure process: (i) condensation between the α-position of pyrrole ring A and the α-acetal unit attached to pyrroline ring B forms the Bacteriochlorin macrocycle, and (ii) Nazarov cyclization of the β-(propenoyl)-substituted ring C forms the isocyclic ring (E). Five new Bacteriochlorins bearing various substituents (alkyl/alkyl, aryl, and alkyl/ester) at positions 2 and 3 (β-pyrrole sites, ring A) and 132 carboalkoxy groups (R = Me or Et) were constructed in 37–61% yield from the hydrobilin analogues. The BC half and AD half are available in five and eight steps, respectively, from the corresponding pyrrole-2-carboxaldehyde and unsaturated ketone. The Bacteriochlorins exhibit absorption spectra typical of bacteriopheophytins (free base bacteriochlorophylls), with a strong near-infrared absorption band (707–751 nm)
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panchromatic chromophore tetrapyrrole light harvesting arrays constructed from bodipy perylene terrylene porphyrin chlorin and Bacteriochlorin building blocks
New Journal of Chemistry, 2016Co-Authors: Rui Liu, David F Bocian, Dewey Holten, Amit Kumar Mandal, Eric J Alexy, Jonathan S LindseyAbstract:Panchromatic absorbers are potentially valuable for use in molecular-based energy-conversion schemes. A prior dyad composed of a perylene-monoimide joined at the 9-position via an ethyne to the porphyrin meso-position afforded panchromatic absorption (350–700 nm). To explore the effects of structure on panchromaticity, five new arrays were synthesized from eight (four new) chromophore or tetrapyrrole building blocks. Two dyads contain a dipyrrinatoboron difluoride (bodipy) or terrylene chromophore in lieu of the perylene to assess the effects of the chromophore π-system on panchromaticity. The long-wavelength absorption band of sparsely substituted variants of the three chromophores (dipyrrinatoboron difluoride, perylene-monoimide, terrylene-monoimide) is generally in the range 480–550 nm, 490–540 nm and 600–660 nm. Three perylene–tetrapyrrole constructs were prepared wherein the perylene–ethyne is attached at the β-pyrrole position of a porphyrin, chlorin, or Bacteriochlorin, versus the meso-site used previously. The latter set addresses the effect of linker connection site on the spectral properties, which is prompted by the differing electron densities at these positions of the three tetrapyrrole macrocycles. A new route is reported for the synthesis of a β-bromoporphyrin building block. Static absorption and emission spectra, fluorescence yields and singlet excited-state lifetimes were examined for all arrays and nine (five new) ethynyl-bearing benchmarks. Four guidelines emerge: (1) panchromaticity decreases in the order perylene > dipyrrinatoboron difluoride > terrylene; (2) the porphyrin meso-site affords far greater panchromaticity than the β-site; (3) panchromaticity for chlorins and Bacteriochlorins is less affected by linker site; and (4) the chromophore–porphyrin dyad with perylene (versus boron-dipyrrin or terrylene) affords the most porphyrin-like and robust lowest singlet excited state for utilization of the harvested energy. Collectively, the new synthetic constructs (5 arrays, 5 benchmarks, 4 building blocks) have elicited heuristics for the de novo design of panchromatic light-harvesting architectures.
Marcin Ptaszek - One of the best experts on this subject based on the ideXlab platform.
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weakly conjugated Bacteriochlorin Bacteriochlorin dyad synthesis and photophysical properties
Journal of Porphyrins and Phthalocyanines, 2021Co-Authors: Brian Uthe, Rachel Gelfand, Matthew Pelton, Marcin PtaszekAbstract:Dyads containing two near-infrared absorbing and emitting Bacteriochlorins with distinct spectral properties have been prepared and characterized by absorption, emission, and transient-absorption s...
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strongly coupled Bacteriochlorin dyad studied using phase modulated fluorescence detected two dimensional electronic spectroscopy
Optics Express, 2018Co-Authors: Vivek Tiwari, Christine Kirmaier, David F Bocian, Dewey Holten, Marcin Ptaszek, Yassel Acosta Matutes, Arkaprabha Konar, Jennifer P OgilvieAbstract: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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excitonic interactions in Bacteriochlorin homo dyads enable charge transfer a new approach to the artificial photosynthetic special pair
Journal of Physical Chemistry B, 2018Co-Authors: Christopher Mccleese, Nopondo N Esemoto, Charles Kolodziej, Buddhadev Maiti, Srijana Bhandari, Barry D Dunietz, Clemens Burda, Marcin PtaszekAbstract:Excitonically coupled Bacteriochlorin (BC) dimers constitute a primary electron donor (special pair) in bacterial photosynthesis and absorbing units in light-harvesting antenna. However, the exact nature of the excited state of these dyads is still not fully understood. Here, we report a detailed spectroscopic and computational investigation of a series of symmetrical Bacteriochlorin dimers, where the Bacteriochlorins are connected either directly or by a phenylene bridge of variable length. The excited state of these dyads is quenched in high-dielectric solvents, which we attribute to photoinduced charge transfer. The mixing of charge transfer with the excitonic state causes accelerated (within 41 ps) decay of the excited state for the directly linked dyad, which is reduced by orders of magnitude with each additional phenyl ring separating the Bacteriochlorins. These results highlight the origins of the excited-state dynamics in symmetric BC dyads and provide a new model for studying the primary processe...
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Excitonic Interactions in Bacteriochlorin Homo-Dyads Enable Charge Transfer: A New Approach to the Artificial Photosynthetic Special Pair
2018Co-Authors: Christopher Mccleese, Nopondo N Esemoto, Charles Kolodziej, Buddhadev Maiti, Srijana Bhandari, Barry D Dunietz, Clemens Burda, Marcin PtaszekAbstract:Excitonically coupled Bacteriochlorin (BC) dimers constitute a primary electron donor (special pair) in bacterial photosynthesis and absorbing units in light-harvesting antenna. However, the exact nature of the excited state of these dyads is still not fully understood. Here, we report a detailed spectroscopic and computational investigation of a series of symmetrical Bacteriochlorin dimers, where the Bacteriochlorins are connected either directly or by a phenylene bridge of variable length. The excited state of these dyads is quenched in high-dielectric solvents, which we attribute to photoinduced charge transfer. The mixing of charge transfer with the excitonic state causes accelerated (within 41 ps) decay of the excited state for the directly linked dyad, which is reduced by orders of magnitude with each additional phenyl ring separating the Bacteriochlorins. These results highlight the origins of the excited-state dynamics in symmetric BC dyads and provide a new model for studying the primary processes in photosynthesis and for the development of artificial, biomimetic systems for solar energy conversion
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bodipy Bacteriochlorin energy transfer arrays toward near ir emitters with broadly tunable multiple absorption bands
Journal of Organic Chemistry, 2017Co-Authors: Adam Meares, Andrius Satraitis, Marcin PtaszekAbstract:A series of energy transfer arrays, comprising a near-IR absorbing and emitting Bacteriochlorin, and BODIPY derivatives with different absorption bands in the visible region (503–668 nm) have been synthesized. Absorption band of BODIPY was tuned by installation of 0, 1, or 2 styryl substituents [2-(2,4,6-trimethoxyphenyl)ethenyl], which leads to derivatives with absorption maxima at 503, 587, and 668 nm, respectively. Efficient energy transfer (>0.90) is observed for each dyad, which is manifested by nearly exclusive emission from Bacteriochlorin moiety upon BODIPY excitation. Fluorescence quantum yield of each dyad in nonpolar solvent (toluene) is comparable with that observed for corresponding Bacteriochlorin monomer, and is significantly reduced in solvent of high dielectric constants (DMF), most likely by photoinduced electron transfer. Given the availability of diverse BODIPY derivatives, with absorption between 500–700 nm, BODIPY–Bacteriochlorin arrays should allow for construction of near-IR emitti...
Dewey Holten - One of the best experts on this subject based on the ideXlab platform.
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strongly coupled Bacteriochlorin dyad studied using phase modulated fluorescence detected two dimensional electronic spectroscopy
Optics Express, 2018Co-Authors: Vivek Tiwari, Christine Kirmaier, David F Bocian, Dewey Holten, Marcin Ptaszek, Yassel Acosta Matutes, Arkaprabha Konar, Jennifer P OgilvieAbstract: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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bioconjugatable pegylated hydroporphyrins for photochemistry and photomedicine narrow band near infrared emitting Bacteriochlorins
New Journal of Chemistry, 2016Co-Authors: Nuonuo Zhang, Jianbing Jiang, Masahiko Taniguchi, David F Bocian, Dewey Holten, Mengran Liu, Amit Kumar Mandal, Rosemary B Evansstorms, Bruce J Pitner, Jonathan S LindseyAbstract: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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panchromatic chromophore tetrapyrrole light harvesting arrays constructed from bodipy perylene terrylene porphyrin chlorin and Bacteriochlorin building blocks
New Journal of Chemistry, 2016Co-Authors: Rui Liu, David F Bocian, Dewey Holten, Amit Kumar Mandal, Eric J Alexy, Jonathan S LindseyAbstract:Panchromatic absorbers are potentially valuable for use in molecular-based energy-conversion schemes. A prior dyad composed of a perylene-monoimide joined at the 9-position via an ethyne to the porphyrin meso-position afforded panchromatic absorption (350–700 nm). To explore the effects of structure on panchromaticity, five new arrays were synthesized from eight (four new) chromophore or tetrapyrrole building blocks. Two dyads contain a dipyrrinatoboron difluoride (bodipy) or terrylene chromophore in lieu of the perylene to assess the effects of the chromophore π-system on panchromaticity. The long-wavelength absorption band of sparsely substituted variants of the three chromophores (dipyrrinatoboron difluoride, perylene-monoimide, terrylene-monoimide) is generally in the range 480–550 nm, 490–540 nm and 600–660 nm. Three perylene–tetrapyrrole constructs were prepared wherein the perylene–ethyne is attached at the β-pyrrole position of a porphyrin, chlorin, or Bacteriochlorin, versus the meso-site used previously. The latter set addresses the effect of linker connection site on the spectral properties, which is prompted by the differing electron densities at these positions of the three tetrapyrrole macrocycles. A new route is reported for the synthesis of a β-bromoporphyrin building block. Static absorption and emission spectra, fluorescence yields and singlet excited-state lifetimes were examined for all arrays and nine (five new) ethynyl-bearing benchmarks. Four guidelines emerge: (1) panchromaticity decreases in the order perylene > dipyrrinatoboron difluoride > terrylene; (2) the porphyrin meso-site affords far greater panchromaticity than the β-site; (3) panchromaticity for chlorins and Bacteriochlorins is less affected by linker site; and (4) the chromophore–porphyrin dyad with perylene (versus boron-dipyrrin or terrylene) affords the most porphyrin-like and robust lowest singlet excited state for utilization of the harvested energy. Collectively, the new synthetic constructs (5 arrays, 5 benchmarks, 4 building blocks) have elicited heuristics for the de novo design of panchromatic light-harvesting architectures.
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Synthesis and Physicochemical Properties of MetalloBacteriochlorins
2016Co-Authors: Chih-yuan Chen, Masahiko Taniguchi, David F Bocian, Dewey Holten, Eunkyung Yang, James R Diers, Dazhong Fan, Erjun Sun, Brian E. Mcdowell, Jonathan S LindseyAbstract:Access to metalloBacteriochlorins is essential for investigation of a wide variety of fundamental photochemical processes, yet relatively few synthetic metalloBacteriochlorins have been prepared. Members of a set of synthetic Bacteriochlorins bearing 0–4 carbonyl groups (1, 2, or 4 carboethoxy substituents, or an annulated imide moiety) were examined under two conditions: (i) standard conditions for zincation of porphyrins [Zn(OAc)2·2H2O in N,N-dimethylformamide (DMF) at 60–80 °C], and (ii) treatment in tetrahydrofuran (THF) with a strong base [e.g., NaH or lithium diisopropylamide (LDA)] followed by a metal reagent MXn. Zincation of Bacteriochlorins that bear 2–4 carbonyl groups proceeded under the former method whereas those with 0–2 carbonyl groups proceeded with NaH or LDA/THF followed by Zn(OTf)2. The scope of metalation (via NaH or LDA in THF) is as follows: (a) for Bacteriochlorins that bear two electron-releasing aryl groups, M = Cu, Zn, Pd, and InCl (but not Mg, Al, Ni, Sn, or Au); (b) for Bacteriochlorins that bear two carboethoxy groups, M = Ni, Cu, Zn, Pd, Cd, InCl, and Sn (but not Mg, Al, or Au); and (c) a Bacteriochlorin with four carboethoxy groups was metalated with Mg (other metals were not examined). Altogether, 15 metalloBacteriochlorins were isolated and characterized. Single-crystal X-ray analysis of 8,8,18,18-tetramethylBacteriochlorin reveals the core geometry provided by the four nitrogen atoms is rectangular; the difference in length of the two sides is ∼0.08 Å. Electronic characteristics of (metal-free) Bacteriochlorins were probed through electrochemical measurements along with density functional theory calculation of the energies of the frontier molecular orbitals. The photophysical properties (fluorescence yields, triplet yields, singlet and triplet excited-state lifetimes) of the zinc Bacteriochlorins are generally similar to those of the metal-free analogues, and to those of the native chromophores bacteriochlorophyll a and bacteriopheophytin a. The availability of diverse metalloBacteriochlorins should prove useful in a variety of fundamental photochemical studies and applications
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integration of cyanine merocyanine and styryl dye motifs with synthetic Bacteriochlorins
Photochemistry and Photobiology, 2016Co-Authors: Eunkyung Yang, Masahiko Taniguchi, Christine Kirmaier, David F Bocian, Jonathan S Lindsey, James R Diers, Nuonuo Zhang, Michael Krayer, Dewey HoltenAbstract:: 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.
David F Bocian - One of the best experts on this subject based on the ideXlab platform.
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strongly coupled Bacteriochlorin dyad studied using phase modulated fluorescence detected two dimensional electronic spectroscopy
Optics Express, 2018Co-Authors: Vivek Tiwari, Christine Kirmaier, David F Bocian, Dewey Holten, Marcin Ptaszek, Yassel Acosta Matutes, Arkaprabha Konar, Jennifer P OgilvieAbstract: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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panchromatic chromophore tetrapyrrole light harvesting arrays constructed from bodipy perylene terrylene porphyrin chlorin and Bacteriochlorin building blocks
New Journal of Chemistry, 2016Co-Authors: Rui Liu, David F Bocian, Dewey Holten, Amit Kumar Mandal, Eric J Alexy, Jonathan S LindseyAbstract:Panchromatic absorbers are potentially valuable for use in molecular-based energy-conversion schemes. A prior dyad composed of a perylene-monoimide joined at the 9-position via an ethyne to the porphyrin meso-position afforded panchromatic absorption (350–700 nm). To explore the effects of structure on panchromaticity, five new arrays were synthesized from eight (four new) chromophore or tetrapyrrole building blocks. Two dyads contain a dipyrrinatoboron difluoride (bodipy) or terrylene chromophore in lieu of the perylene to assess the effects of the chromophore π-system on panchromaticity. The long-wavelength absorption band of sparsely substituted variants of the three chromophores (dipyrrinatoboron difluoride, perylene-monoimide, terrylene-monoimide) is generally in the range 480–550 nm, 490–540 nm and 600–660 nm. Three perylene–tetrapyrrole constructs were prepared wherein the perylene–ethyne is attached at the β-pyrrole position of a porphyrin, chlorin, or Bacteriochlorin, versus the meso-site used previously. The latter set addresses the effect of linker connection site on the spectral properties, which is prompted by the differing electron densities at these positions of the three tetrapyrrole macrocycles. A new route is reported for the synthesis of a β-bromoporphyrin building block. Static absorption and emission spectra, fluorescence yields and singlet excited-state lifetimes were examined for all arrays and nine (five new) ethynyl-bearing benchmarks. Four guidelines emerge: (1) panchromaticity decreases in the order perylene > dipyrrinatoboron difluoride > terrylene; (2) the porphyrin meso-site affords far greater panchromaticity than the β-site; (3) panchromaticity for chlorins and Bacteriochlorins is less affected by linker site; and (4) the chromophore–porphyrin dyad with perylene (versus boron-dipyrrin or terrylene) affords the most porphyrin-like and robust lowest singlet excited state for utilization of the harvested energy. Collectively, the new synthetic constructs (5 arrays, 5 benchmarks, 4 building blocks) have elicited heuristics for the de novo design of panchromatic light-harvesting architectures.
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bioconjugatable pegylated hydroporphyrins for photochemistry and photomedicine narrow band near infrared emitting Bacteriochlorins
New Journal of Chemistry, 2016Co-Authors: Nuonuo Zhang, Jianbing Jiang, Masahiko Taniguchi, David F Bocian, Dewey Holten, Mengran Liu, Amit Kumar Mandal, Rosemary B Evansstorms, Bruce J Pitner, Jonathan S LindseyAbstract: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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integration of cyanine merocyanine and styryl dye motifs with synthetic Bacteriochlorins
Photochemistry and Photobiology, 2016Co-Authors: Eunkyung Yang, Masahiko Taniguchi, Christine Kirmaier, David F Bocian, Jonathan S Lindsey, James R Diers, Nuonuo Zhang, Michael Krayer, Dewey HoltenAbstract:: 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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Synthesis and Physicochemical Properties of MetalloBacteriochlorins
2016Co-Authors: Chih-yuan Chen, Masahiko Taniguchi, David F Bocian, Dewey Holten, Eunkyung Yang, James R Diers, Dazhong Fan, Erjun Sun, Brian E. Mcdowell, Jonathan S LindseyAbstract:Access to metalloBacteriochlorins is essential for investigation of a wide variety of fundamental photochemical processes, yet relatively few synthetic metalloBacteriochlorins have been prepared. Members of a set of synthetic Bacteriochlorins bearing 0–4 carbonyl groups (1, 2, or 4 carboethoxy substituents, or an annulated imide moiety) were examined under two conditions: (i) standard conditions for zincation of porphyrins [Zn(OAc)2·2H2O in N,N-dimethylformamide (DMF) at 60–80 °C], and (ii) treatment in tetrahydrofuran (THF) with a strong base [e.g., NaH or lithium diisopropylamide (LDA)] followed by a metal reagent MXn. Zincation of Bacteriochlorins that bear 2–4 carbonyl groups proceeded under the former method whereas those with 0–2 carbonyl groups proceeded with NaH or LDA/THF followed by Zn(OTf)2. The scope of metalation (via NaH or LDA in THF) is as follows: (a) for Bacteriochlorins that bear two electron-releasing aryl groups, M = Cu, Zn, Pd, and InCl (but not Mg, Al, Ni, Sn, or Au); (b) for Bacteriochlorins that bear two carboethoxy groups, M = Ni, Cu, Zn, Pd, Cd, InCl, and Sn (but not Mg, Al, or Au); and (c) a Bacteriochlorin with four carboethoxy groups was metalated with Mg (other metals were not examined). Altogether, 15 metalloBacteriochlorins were isolated and characterized. Single-crystal X-ray analysis of 8,8,18,18-tetramethylBacteriochlorin reveals the core geometry provided by the four nitrogen atoms is rectangular; the difference in length of the two sides is ∼0.08 Å. Electronic characteristics of (metal-free) Bacteriochlorins were probed through electrochemical measurements along with density functional theory calculation of the energies of the frontier molecular orbitals. The photophysical properties (fluorescence yields, triplet yields, singlet and triplet excited-state lifetimes) of the zinc Bacteriochlorins are generally similar to those of the metal-free analogues, and to those of the native chromophores bacteriochlorophyll a and bacteriopheophytin a. The availability of diverse metalloBacteriochlorins should prove useful in a variety of fundamental photochemical studies and applications
James R Diers - One of the best experts on this subject based on the ideXlab platform.
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integration of cyanine merocyanine and styryl dye motifs with synthetic Bacteriochlorins
Photochemistry and Photobiology, 2016Co-Authors: Eunkyung Yang, Masahiko Taniguchi, Christine Kirmaier, David F Bocian, Jonathan S Lindsey, James R Diers, Nuonuo Zhang, Michael Krayer, Dewey HoltenAbstract:: 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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Synthesis and Physicochemical Properties of MetalloBacteriochlorins
2016Co-Authors: Chih-yuan Chen, Masahiko Taniguchi, David F Bocian, Dewey Holten, Eunkyung Yang, James R Diers, Dazhong Fan, Erjun Sun, Brian E. Mcdowell, Jonathan S LindseyAbstract:Access to metalloBacteriochlorins is essential for investigation of a wide variety of fundamental photochemical processes, yet relatively few synthetic metalloBacteriochlorins have been prepared. Members of a set of synthetic Bacteriochlorins bearing 0–4 carbonyl groups (1, 2, or 4 carboethoxy substituents, or an annulated imide moiety) were examined under two conditions: (i) standard conditions for zincation of porphyrins [Zn(OAc)2·2H2O in N,N-dimethylformamide (DMF) at 60–80 °C], and (ii) treatment in tetrahydrofuran (THF) with a strong base [e.g., NaH or lithium diisopropylamide (LDA)] followed by a metal reagent MXn. Zincation of Bacteriochlorins that bear 2–4 carbonyl groups proceeded under the former method whereas those with 0–2 carbonyl groups proceeded with NaH or LDA/THF followed by Zn(OTf)2. The scope of metalation (via NaH or LDA in THF) is as follows: (a) for Bacteriochlorins that bear two electron-releasing aryl groups, M = Cu, Zn, Pd, and InCl (but not Mg, Al, Ni, Sn, or Au); (b) for Bacteriochlorins that bear two carboethoxy groups, M = Ni, Cu, Zn, Pd, Cd, InCl, and Sn (but not Mg, Al, or Au); and (c) a Bacteriochlorin with four carboethoxy groups was metalated with Mg (other metals were not examined). Altogether, 15 metalloBacteriochlorins were isolated and characterized. Single-crystal X-ray analysis of 8,8,18,18-tetramethylBacteriochlorin reveals the core geometry provided by the four nitrogen atoms is rectangular; the difference in length of the two sides is ∼0.08 Å. Electronic characteristics of (metal-free) Bacteriochlorins were probed through electrochemical measurements along with density functional theory calculation of the energies of the frontier molecular orbitals. The photophysical properties (fluorescence yields, triplet yields, singlet and triplet excited-state lifetimes) of the zinc Bacteriochlorins are generally similar to those of the metal-free analogues, and to those of the native chromophores bacteriochlorophyll a and bacteriopheophytin a. The availability of diverse metalloBacteriochlorins should prove useful in a variety of fundamental photochemical studies and applications
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Effects of Strong Electronic Coupling in Chlorin and Bacteriochlorin Dyads
2016Co-Authors: Hyun Suk Kang, Dariusz M Niedzwiedzki, James R Diers, Nopondo N Esemoto, Jordan A. Greco, Joshua Akhigbe, Chirag Pancholi, Ganga Viswanathan Bhagavathy, Jamie K. NguyenAbstract: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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extending the short and long wavelength limits of Bacteriochlorin near infrared absorption via dioxo and bisimide functionalization
Journal of Physical Chemistry B, 2015Co-Authors: Pothiappan Vairaprakash, Dariusz M Niedzwiedzki, Masahiko Taniguchi, Christine Kirmaier, Eunkyung Yang, James R Diers, Tuba Sahin, Michael Krayer, Alfred Wang, Jonathan S LindseyAbstract:Six new Bacteriochlorins expanding the range of the strong near-infrared (NIR) absorption (Qy band) to both shorter and longer wavelengths (∼690 to ∼900 nm) have been synthesized and characterized. The architectures include Bacteriochlorin–bisimides that have six-membered imide rings spanning the 3,5- and 13,15-macrocycle positions or five-membered imide rings spanning the β-pyrrolic 2,3- and 12,13-positions. Both bisimide types absorb at significantly longer wavelength than the Bacteriochlorin precursors (no fused rings), whereas oxo-groups at the 7- or 7,17-positions shift the Qy band to a new short wavelength limit. Surprisingly, Bacteriochlorin–bisimides with five-membered β-pyrrolic-centered imide rings have a Qy band closer to that of six-membered Bacteriochlorin–monoimides. However, the five-membered bisimides (versus the six-membered Bacteriochlorin–monoimides) have significantly enhanced absorption intensity that is paralleled by an ∼2-fold higher fluorescence yield (∼0.16 vs ∼0.07) and longer si...
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Extending the Short and Long Wavelength Limits of Bacteriochlorin Near-Infrared Absorption via Dioxo- and Bisimide-Functionalization
2015Co-Authors: Pothiappan Vairaprakash, Dariusz M Niedzwiedzki, Masahiko Taniguchi, Christine Kirmaier, Eunkyung Yang, James R Diers, Tuba Sahin, Michael Krayer, Alfred Wang, Jonathan S LindseyAbstract:Six new Bacteriochlorins expanding the range of the strong near-infrared (NIR) absorption (Qy band) to both shorter and longer wavelengths (∼690 to ∼900 nm) have been synthesized and characterized. The architectures include Bacteriochlorin–bisimides that have six-membered imide rings spanning the 3,5- and 13,15-macrocycle positions or five-membered imide rings spanning the β-pyrrolic 2,3- and 12,13-positions. Both bisimide types absorb at significantly longer wavelength than the Bacteriochlorin precursors (no fused rings), whereas oxo-groups at the 7- or 7,17-positions shift the Qy band to a new short wavelength limit. Surprisingly, Bacteriochlorin–bisimides with five-membered β-pyrrolic-centered imide rings have a Qy band closer to that of six-membered Bacteriochlorin–monoimides. However, the five-membered bisimides (versus the six-membered Bacteriochlorin–monoimides) have significantly enhanced absorption intensity that is paralleled by an ∼2-fold higher fluorescence yield (∼0.16 vs ∼0.07) and longer singlet excited-state lifetime (∼4 ns vs ∼2 ns). The photophysical enhancements derive in part from mixing of the lowest unoccupied frontier molecular orbitals of the five-membered imide ring with those of the Bacteriochlorin framework. In general, all of the new Bacteriochlorins have excited-state lifetimes (1–4 ns) that are sufficiently long for use in molecular-based systems for photochemical applications
