276
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Fathalla M, Barnes JC, Young RM, Hartlieb KJ, Dyar SM, Eaton SW, Sarjeant AA, Co DT, Wasielewski MR, Stoddart JF. Photoinduced Electron Transfer within a Zinc Porphyrin-Cyclobis(paraquat-p-phenylene) Donor-Acceptor Dyad. Chemistry 2014; 20:14690-7. [DOI: 10.1002/chem.201403744] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Indexed: 12/12/2022]
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277
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Shim Y, Young RM, Douvalis AP, Dyar SM, Yuhas BD, Bakas T, Wasielewski MR, Kanatzidis MG. Enhanced Photochemical Hydrogen Evolution from Fe4S4-Based Biomimetic Chalcogels Containing M2+ (M = Pt, Zn, Co, Ni, Sn) Centers. J Am Chem Soc 2014; 136:13371-80. [DOI: 10.1021/ja507297p] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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278
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Hartnett PE, Dyar SM, Margulies EA, Shoer LE, Cook AW, Eaton SW, Marks TJ, Wasielewski MR. Long-lived charge carrier generation in ordered films of a covalent perylenediimide-diketopyrrolopyrrole-perylenediimide molecule. Chem Sci 2014; 6:402-411. [PMID: 28936299 PMCID: PMC5587985 DOI: 10.1039/c4sc02551b] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/16/2014] [Indexed: 11/21/2022] Open
Abstract
The photophysics of a covalently linked perylenediimide-diketopyrrolopyrrole-perylenediimide acceptor-donor-acceptor molecule (PDI-DPP-PDI, 1) were investigated and found to be markedly different in solution versus in unannealed and solvent annealed films. Photoexcitation of 1 in toluene results in quantitative charge separation in τ = 3.1 ± 0.2 ps, with charge recombination in τ = 340 ± 10 ps, while in unannealed/disordered films of 1, charge separation occurs in τ < 250 fs, while charge recombination displays a multiexponential decay in ∼6 ns. The absence of long-lived, charge separation in the disordered film suggests that few free charge carriers are generated. In contrast, upon CH2Cl2 vapor annealing films of 1, grazing-incidence X-ray scattering shows that the molecules form a more ordered structure. Photoexcitation of the ordered films results in initial formation of a spin-correlated radical ion pair (electron-hole pair) as indicated by magnetic field effects on the formation of free charge carriers which live for ∼4 μs. This result has significant implications for the design of organic solar cells based on covalent donor-acceptor systems and shows that long-lived, charge-separated states can be achieved by controlling intramolecular charge separation dynamics in well-ordered systems.
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279
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Co NP, Young RM, Smeigh AL, Wasielewski MR, Hoffman BM. Symmetrized photoinitiated electron flow within the [myoglobin:cytochrome b₅] complex on singlet and triplet time scales: energetics vs dynamics. J Am Chem Soc 2014; 136:12730-6. [PMID: 25133915 PMCID: PMC4160274 DOI: 10.1021/ja506388c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We report here that photoinitiated electron flow involving a metal-substituted (M = Mg, Zn) myoglobin (Mb) and its physiological partner protein, cytochrome b5 (cyt b5) can be "symmetrized": the [Mb:cyt b5] complex stabilized by three D/E → K mutations on Mb (D44K/D60K/E85K, denoted MMb) exhibits both oxidative and reductive ET quenching of both the singlet and triplet photoexcited MMb states, the direction of flow being determined by the oxidation state of the cyt b5 partner. The first-excited singlet state of MMb ((1)MMb) undergoes ns-time scale reductive ET quenching by Fe(2+)cyt b5 as well as ns-time scale oxidative ET quenching by Fe(3+)cyt b5, both processes involving an ensemble of structures that do not interconvert on this time scale. Despite a large disparity in driving force favoring photooxidation of (1)MMb relative to photoreduction (δ(-ΔG(0)) ≈ 0.4 eV, M = Mg; ≈ 0.2 eV, M = Zn), for each M the average rate constants for the two reactions are the same within error, (1)k(f) > 10(8) s(-1). This surprising observation is explained by considering the driving-force dependence of the Franck-Condon factor in the Marcus equation. The triplet state of the myoglobin ((3)MMb) created by intersystem crossing from (1)MMb likewise undergoes reductive ET quenching by Fe(2+)cyt b5 as well as oxidative ET quenching by Fe(3+)cyt b5. As with singlet ET, the rate constants for oxidative ET quenching and reductive ET quenching on the triplet time scale are the same within error, (3)k(f) ≈ 10(5) s(-1), but here the equivalence is attributable to gating by intracomplex conversion among a conformational ensemble.
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280
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Brown KE, Salamant WA, Shoer LE, Young RM, Wasielewski MR. Direct Observation of Ultrafast Excimer Formation in Covalent Perylenediimide Dimers Using Near-Infrared Transient Absorption Spectroscopy. J Phys Chem Lett 2014; 5:2588-93. [PMID: 26277948 DOI: 10.1021/jz5011797] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Energy transfer in perylene-3,4:9,10-bis(dicarboximide) (PDI) aggregates is often limited by formation of a low-energy excimer state. Formation dynamics of excimer states are often characterized by line shape changes and peak shift dynamics in femtosecond visible transient absorption spectra. Femtosecond near-infrared transient absorption experiments reveal a unique low-energy transition that can be used to identify and characterize this state without overlapping excited singlet-state absorption. Three covalently bound PDI dimers with differing PDI-PDI distances were studied to probe the influence of interchromophore electronic coupling on the PDI excimer transient spectra and dynamics.
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281
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Frasconi M, Kikuchi T, Cao D, Wu Y, Liu WG, Dyar SM, Barin G, Sarjeant AA, Stern CL, Carmieli R, Wang C, Wasielewski MR, Goddard WA, Stoddart JF. Mechanical Bonds and Topological Effects in Radical Dimer Stabilization. J Am Chem Soc 2014; 136:11011-26. [DOI: 10.1021/ja504662a] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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282
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Barnes JC, Frasconi M, Young RM, Khdary NH, Liu WG, Dyar SM, McGonigal PR, Gibbs-Hall IC, Diercks CS, Sarjeant AA, Stern CL, Goddard WA, Wasielewski MR, Stoddart JF. Solid-State Characterization and Photoinduced Intramolecular Electron Transfer in a Nanoconfined Octacationic Homo[2]Catenane. J Am Chem Soc 2014; 136:10569-72. [DOI: 10.1021/ja505093d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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283
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Wu Y, Frasconi M, Gardner DM, McGonigal PR, Schneebeli ST, Wasielewski MR, Stoddart JF. Electron delocalization in a rigid cofacial naphthalene-1,8:4,5-bis(dicarboximide) dimer. Angew Chem Int Ed Engl 2014; 53:9476-81. [PMID: 25044761 DOI: 10.1002/anie.201403816] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Indexed: 12/12/2022]
Abstract
Investigating through-space electronic communication between discrete cofacially oriented aromatic π-systems is fundamental to understanding assemblies as diverse as double-stranded DNA, organic photovoltaics and thin-film transistors. A detailed understanding of the electronic interactions involved rests on making the appropriate molecular compounds with rigid covalent scaffolds and π-π distances in the range of ca. 3.5 Å. Reported herein is an enantiomeric pair of doubly-bridged naphthalene-1,8:4,5-bis(dicarboximide) (NDI) cyclophanes and the characterization of four of their electronic states, namely 1) the ground state, 2) the exciton coupled singlet excited state, 3) the radical anion with strong through-space interactions between the redox-active NDI molecules, and 4) the diamagnetic diradical dianion using UV/Vis/NIR, EPR and ENDOR spectroscopies in addition to X-ray crystallography. Despite the unfavorable Coulombic repulsion, the singlet diradical dianion dimer of NDI shows a more pronounced intramolecular π-π stacking interaction when compared with its neutral analog.
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284
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Wu Y, Frasconi M, Gardner DM, McGonigal PR, Schneebeli ST, Wasielewski MR, Stoddart JF. Electron Delocalization in a Rigid Cofacial Naphthalene-1,8:4,5-bis(dicarboximide) Dimer. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201403816] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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285
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Zarea M, Carmieli R, Ratner MA, Wasielewski MR. Spin Dynamics of Radical Pairs with Restricted Geometries and Strong Exchange Coupling: The Role of Hyperfine Coupling. J Phys Chem A 2014; 118:4249-55. [DOI: 10.1021/jp5039283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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286
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Dyar SM, Barnes JC, Juríček M, Stoddart JF, Co DT, Young RM, Wasielewski MR. Electron Transfer and Multi-Electron Accumulation in ExBox4+. Angew Chem Int Ed Engl 2014; 53:5371-5. [DOI: 10.1002/anie.201402444] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Indexed: 12/17/2022]
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287
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Lefler KM, Kim CH, Wu YL, Wasielewski MR. Self-Assembly of Supramolecular Light-Harvesting Arrays from Symmetric Perylene-3,4-dicarboximide Trefoils. J Phys Chem Lett 2014; 5:1608-1615. [PMID: 26270104 DOI: 10.1021/jz500626g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Unlike the widely studied perylene-3,4:9,10-bis(dicarboximide) (PDI) dyes, self-assembly of the corresponding perylene-3,4-dicarboximide (PMI) dyes into large arrays and studies of their excited state properties have received far less attention. Two symmetric PMI trefoils were synthesized by connecting the 9-position of the perylene core either directly (1) or through a phenylene linker (2) to the 1,3,5-positions of a central benzene ring. Synchrotron-based small- and wide-angle X-ray scattering measurements in methylcyclohexane show that trefoil 1 self-assembles into cofacial trimers (13) on average, while trefoil 2 forms much larger assemblies that are tridecamers (213) on average. Their photophysics were characterized using steady-state as well as transient absorption and emission spectroscopy. Time-resolved spectroscopy reveals that both 13 and 213 initially form excitonically coupled excited states that subsequently relax to excimer states having 20 and 8.4 ns lifetimes, respectively, which decay to ground-state primarily nonradiatively. The data are consistent with stronger electronic coupling between the PMI molecules in 213 relative to 13.
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288
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Dyar SM, Barnes JC, Juríček M, Stoddart JF, Co DT, Young RM, Wasielewski MR. Electron Transfer and Multi-Electron Accumulation in ExBox4+. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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289
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Chen HF, Gardner DM, Carmieli R, Wasielewski MR. Controlling the orientation of spin-correlated radical pairs by covalent linkage to nanoporous anodic aluminum oxide membranes. Chem Commun (Camb) 2014; 49:8614-6. [PMID: 23955433 DOI: 10.1039/c3cc45129a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ordered multi-spin assemblies are required for developing solid-state molecule-based spintronics. A linear donor-chromophore-acceptor (D-C-A) molecule was covalently attached inside the 150 nm diam. nanopores of an anodic aluminum oxide (AAO) membrane. Photoexcitation of D-C-A in a 343 mT magnetic field results in sub-nanosecond, two-step electron transfer to yield the spin-correlated radical ion pair (SCRP) (1)(D(+)˙-C-A(-)˙), which then undergoes radical pair intersystem crossing (RP-ISC) to yield (3)(D(+)˙-C-A(-)˙). RP-ISC results in S-T0 mixing to selectively populate the coherent superposition states |S'> and |T'>. Microwave-induced transitions between these states and the unpopulated |T(+1)> and |T(-1)> states result in spin-polarized time-resolved EPR (TREPR) spectra. The dependence of the electron spin polarization (ESP) phase of the TREPR spectra on the orientation of the AAO membrane pores relative to the externally applied magnetic field is used to determine the overall orientation of the SCRPs within the pores at room temperature.
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290
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Avestro AJ, Gardner DM, Vermeulen NA, Wilson EA, Schneebeli ST, Whalley AC, Belowich ME, Carmieli R, Wasielewski MR, Stoddart JF. Gated electron sharing within dynamic naphthalene diimide-based oligorotaxanes. Angew Chem Int Ed Engl 2014; 53:4442-9. [PMID: 24623608 DOI: 10.1002/anie.201309680] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Indexed: 12/12/2022]
Abstract
The controlled self-assembly of well-defined and spatially ordered π-systems has attracted considerable interest because of their potential applications in organic electronics. An important contemporary pursuit relates to the investigation of charge transport across noncovalently coupled components in a stepwise fashion. Dynamic oligorotaxanes, prepared by template-directed methods, provide a scaffold for directing the construction of monodisperse one-dimensional assemblies in which the functional units communicate electronically through-space by way of π-orbital interactions. Reported herein is a series of oligorotaxanes containing one, two, three and four naphthalene diimide (NDI) redox-active units, which have been shown by cyclic voltammetry, and by EPR and ENDOR spectroscopies, to share electrons across the NDI stacks. Thermally driven motions between the neighboring NDI units in the oligorotaxanes influence the passage of electrons through the NDI stacks in a manner reminiscent of the conformationally gated charge transfer observed in DNA.
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291
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Avestro AJ, Gardner DM, Vermeulen NA, Wilson EA, Schneebeli ST, Whalley AC, Belowich ME, Carmieli R, Wasielewski MR, Stoddart JF. Gated Electron Sharing Within Dynamic Naphthalene Diimide-Based Oligorotaxanes. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309680] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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292
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Roznyatovskiy VV, Carmieli R, Dyar SM, Brown KE, Wasielewski MR. Photodriven Charge Separation and Transport in Self-Assembled Zinc Tetrabenzotetraphenylporphyrin and Perylenediimide Charge Conduits. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309335] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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293
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Roznyatovskiy VV, Carmieli R, Dyar SM, Brown KE, Wasielewski MR. Photodriven Charge Separation and Transport in Self-Assembled Zinc Tetrabenzotetraphenylporphyrin and Perylenediimide Charge Conduits. Angew Chem Int Ed Engl 2014; 53:3457-61. [DOI: 10.1002/anie.201309335] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/10/2013] [Indexed: 11/10/2022]
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294
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Zarea M, Ratner MA, Wasielewski MR. Electron transfer in a two-level system within a Cole-Davidson vitreous bath. J Chem Phys 2014; 140:024110. [DOI: 10.1063/1.4860972] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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295
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Roznyatovskiy VV, Gardner DM, Eaton SW, Wasielewski MR. Radical Anions of Trifluoromethylated Perylene and Naphthalene Imide and Diimide Electron Acceptors. Org Lett 2014; 16:696-9. [DOI: 10.1021/ol403736m] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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296
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Neelakandan PP, Zeidan TA, McCullagh M, Schatz GC, Vura-Weis J, Kim CH, Wasielewski MR, Lewis FD. Ground and excited state electronic spectra of perylenediimide dimers with flexible and rigid geometries in DNA conjugates. Chem Sci 2014. [DOI: 10.1039/c3sc52908h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ground and excited state spectra of co-facial PDI dimers embedded in DNA constructs depend on the geometry imposed by the construct.
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297
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Schneebeli ST, Frasconi M, Liu Z, Wu Y, Gardner DM, Strutt NL, Cheng C, Carmieli R, Wasielewski MR, Stoddart JF. Rücktitelbild: Electron Sharing and Anion-π Recognition in Molecular Triangular Prisms (Angew. Chem. 49/2013). Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201309249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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298
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Li H, Cheng C, McGonigal PR, Fahrenbach AC, Frasconi M, Liu WG, Zhu Z, Zhao Y, Ke C, Lei J, Young RM, Dyar SM, Co DT, Yang YW, Botros YY, Goddard WA, Wasielewski MR, Astumian RD, Stoddart JF. Relative Unidirectional Translation in an Artificial Molecular Assembly Fueled by Light. J Am Chem Soc 2013; 135:18609-20. [DOI: 10.1021/ja4094204] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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299
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Johnson DG, Svec WA, Wasielewski MR. Solvent Polarity Dependent Photophysics of a Fixed-Distance, Symmetric Chlorophyll Dimer. A Model of the Special Pair in Photosynthetic Reaction Centers. Isr J Chem 2013. [DOI: 10.1002/ijch.198800030] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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300
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Schneebeli ST, Frasconi M, Liu Z, Wu Y, Gardner DM, Strutt NL, Cheng C, Carmieli R, Wasielewski MR, Stoddart JF. Electron Sharing and Anion-π Recognition in Molecular Triangular Prisms. Angew Chem Int Ed Engl 2013; 52:13100-4. [DOI: 10.1002/anie.201307984] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Indexed: 12/12/2022]
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