51
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Peng Q, Niu Y, Wang Z, Jiang Y, Li Y, Liu Y, Shuai Z. Theoretical predictions of red and near-infrared strongly emitting X-annulated rylenes. J Chem Phys 2011; 134:074510. [PMID: 21341862 PMCID: PMC3071303 DOI: 10.1063/1.3549143] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 01/07/2011] [Indexed: 12/22/2022] Open
Abstract
The optical properties of rylenes are extremely interesting because their emission colors can be tuned from blue to near-infrared by simply elongating the chain length. However, for conjugated chains, the dipole-allowed odd-parity 1B(u) excited state often lies above the dipole-forbidden even-parity 2A(g) state as the chain length increases, thus preventing any significant luminescence according to Kasha's rule. We systemically investigated the 1B(u)∕2A(g) crossover behaviors with respect to the elongating rylene chain length with various quantum chemistry approaches, such as time-depended density functional theory (TDDFT), complete active space self-consistent field theory (CASSCF∕CASPT2), multireference configuration interaction (MRCI)∕Zerner's intermediate neglect of diatomic overlap (ZINDO), and MRCI∕modified neglect of differential overlap. The calculated results by CASSCF∕CASPT2 and MRCI∕ZINDO are completely coherent: the optical active 1B(u) state lies below the dark B(3g) or 2A(g) state for perylene and terrylene, which results in strong fluorescence; while a crossover to S(1) = 2A(g) occurs and leads to much weaker fluorescence for quaterrylene. Then we put forward a molecular design rule on how to recover fluorescence for the longer rylenes by introducing heteroatom bridges. Several heteroatom-annulated rylenes are designed theoretically, which are predicted to be strongly emissive in the red and near-infrared ranges. These are further confirmed by theoretical emission spectra as well as radiative and nonradiative decay rate calculations by using the vibration correlation function formalisms we developed earlier coupled with TDDFT.
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Affiliation(s)
- Qian Peng
- Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Science (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of China
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52
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Huh J, Berger R. Application of time-independent cumulant expansion to calculation of Franck–Condon profiles for large molecular systems. Faraday Discuss 2011; 150:363-73; discussion 391-418. [DOI: 10.1039/c0fd00014k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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53
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Cataldo F, Iglesias-Groth S, Manchado A. Electronic absorption spectroscopy of polycyclic aromatic hydrocarbons (PAHs) radical cations generated in oleum: a superacid medium. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:998-1004. [PMID: 20863743 DOI: 10.1016/j.saa.2010.08.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2010] [Revised: 08/22/2010] [Accepted: 08/23/2010] [Indexed: 05/29/2023]
Abstract
Oleum (fuming sulphuric acid), a well known superacid, was used as medium for the generation of the radical cation of a series of selected PAHs. The resulting radical cation spectra were studied by electronic absorption spectroscopy. Not only common PAHs like naphthalene, anthracene, tetracene, pentacene, perylene, pyrene, benzo[a]pyrene, phenanthrene and picene were studied but also the less common and very large PAHs relevant also for the astrochemical research, like coronene, hexabenzocoronene, quaterrylene, dicoronylene and a coronene oligomer. A correlation between the first ionization potential (IP1) of the PAHs studied and the energy to the so-called A-type band of the radical cations observed in oleum has led to the equation IP1=1.30EA+4.39 (in eV) which permits to estimate the energy of the PAHs radical cation transition (EA) in the VIS-NIR knowing the relative ionization potential or vice versa.
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Affiliation(s)
- Franco Cataldo
- Istituto Nazionale di Astrofisica-Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy.
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54
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Knippenberg S, Starcke JH, Wormit M, Dreuw A. The low-lying excited states of neutral polyacenes and their radical cations: a quantum chemical study employing the algebraic diagrammatic construction scheme of second order. Mol Phys 2010. [DOI: 10.1080/00268976.2010.526643] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Stefan Knippenberg
- a Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt , Max von Laue-Str. 7, 60438 Frankfurt , Germany
| | - Jan Hendrik Starcke
- a Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt , Max von Laue-Str. 7, 60438 Frankfurt , Germany
| | - Michael Wormit
- a Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt , Max von Laue-Str. 7, 60438 Frankfurt , Germany
| | - Andreas Dreuw
- a Institut für Physikalische und Theoretische Chemie, Goethe-Universität Frankfurt , Max von Laue-Str. 7, 60438 Frankfurt , Germany
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55
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56
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Dienel T, Krause A, Alle R, Forker R, Meerholz K, Fritz T. Alkali metal doped organic molecules on insulators: charge impact on the optical properties. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:4064-70. [PMID: 20715065 DOI: 10.1002/adma.201000891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Thomas Dienel
- Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden, Germany.
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57
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Tokmachev AM, Boggio-Pasqua M, Mendive-Tapia D, Bearpark MJ, Robb MA. Fluorescence of the perylene radical cation and an inaccessible D0/D1 conical intersection: An MMVB, RASSCF, and TD-DFT computational study. J Chem Phys 2010; 132:044306. [DOI: 10.1063/1.3278545] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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Ponceâ
Ortiz R, Casado J, RodrÃguezâ
González S, Hernández VÃ, Lópezâ
Navarreteâ J, Viruela P, OrtÃâ E, Takimiya K, Otsubo T. Quinoidal Oligothiophenes: Towards Biradical Ground-State Species. Chemistry 2010; 16:470-84. [DOI: 10.1002/chem.200902037] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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59
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Dobryakov AL, Ernsting NP. Lineshapes for resonant impulsive stimulated Raman scattering with chirped pump and supercontinuum probe pulses. J Chem Phys 2009; 129:184504. [PMID: 19045411 DOI: 10.1063/1.3009221] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular vibrational coherence from impulsive stimulated Raman (SR) scattering, as observed by broadband transient absorption spectroscopy, is treated within the well-known third-order perturbation formalism. Shaped femtosecond optical pulses are used for the pump and supercontinuum probe fields. Dephasing is assumed to be homogeneous in the Bloch approximation. A key step requires threefold time integration over response functions and electric fields. For well-separated pulses the triple integral can be solved analytically, resulting in lineshape functions. These allow to describe the SR signal through absorption/emission/dispersion profiles which are associated with the inherent contributions. A clear physical interpretation of the amplitude and phase of the oscillatory signal is thereby obtained, and a direct connection with the vibronic structure of the molecular system is provided. Calculations for model molecular systems illustrate the spectral dependence of the vibrational coherence seen, for example, with perylene in cyclohexane. The nonoscillatory and oscillatory parts of the transient absorption spectra are compared to each other. Observed mode beatings are explained.
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Affiliation(s)
- A L Dobryakov
- Department of Chemistry, Humboldt University, D-12489 Berlin, Germany.
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60
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Miura M, Aoki Y. Ab initiotheory for treating local electron excitations in molecules and its performance for computing optical properties. J Comput Chem 2009; 30:2213-30. [DOI: 10.1002/jcc.21206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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61
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Hammonds M, Pathak A, Sarre PJ. TD-DFT calculations of electronic spectra of hydrogenated protonated polycyclic aromatic hydrocarbon (PAH) molecules: implications for the origin of the diffuse interstellar bands? Phys Chem Chem Phys 2009; 11:4458-64. [DOI: 10.1039/b903237a] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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62
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Stearns JA, Pillsbury NR, Douglass KO, Müller CW, Zwier TS, Plusquellic DF. Rotationally resolved studies of S0 and the exciton coupled S1/S2 origin regions of diphenylmethane and the d12 isotopologue. J Chem Phys 2008; 129:224305. [DOI: 10.1063/1.3028543] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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63
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Tokmachev AM, Boggio-Pasqua M, Bearpark MJ, Robb MA. Photostability via Sloped Conical Intersections: A Computational Study of the Pyrene Radical Cation. J Phys Chem A 2008; 112:10881-6. [DOI: 10.1021/jp8044109] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Andrei M. Tokmachev
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom, and Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université Toulouse 3, 118 route de Narbonne, 31062 Toulouse, France
| | - Martial Boggio-Pasqua
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom, and Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université Toulouse 3, 118 route de Narbonne, 31062 Toulouse, France
| | - Michael J. Bearpark
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom, and Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université Toulouse 3, 118 route de Narbonne, 31062 Toulouse, France
| | - Michael A. Robb
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom, and Laboratoire de Chimie et Physique Quantiques, UMR 5626, IRSAMC, CNRS et Université Toulouse 3, 118 route de Narbonne, 31062 Toulouse, France
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64
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65
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Brüggemann B, Persson P, Meyer HD, May V. Frequency dispersed transient absorption spectra of dissolved perylene: A case study using the density matrix version of the MCTDH method. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2007.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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66
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Radiation Effects On DNA: Theoretical Investigations Of Electron, Hole And Excitation Pathways To DNA Damage. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/978-1-4020-8184-2_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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67
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Villagomez CJ, Zambelli T, Gauthier S, Gourdon A, Barthes C, Stojkovic S, Joachim C. A local view on hyperconjugation. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.11.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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68
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Gundlach L, Willig F. Time-resolved electron transfer from the excited singlet state of anchored perylene into Ag(110). Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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69
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Malloci G, Mulas G, Cappellini G, Joblin C. Time-dependent density functional study of the electronic spectra of oligoacenes in the charge states −1, 0, +1, and +2. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.07.046] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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70
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Ryderfors L, Mukhtar E, Johansson LBÅ. The Symmetry of Two-Photon Excited States as Determined by Time-Resolved Fluorescence Depolarization Experiments. J Phys Chem A 2007; 111:11531-9. [DOI: 10.1021/jp074506g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Linus Ryderfors
- Department of Photochemistry and Molecular Science, Uppsala University, P. O. Box 523, S-751 20 Uppsala, Sweden, and Department of Chemistry/Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden
| | - Emad Mukhtar
- Department of Photochemistry and Molecular Science, Uppsala University, P. O. Box 523, S-751 20 Uppsala, Sweden, and Department of Chemistry/Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden
| | - Lennart B.-Å. Johansson
- Department of Photochemistry and Molecular Science, Uppsala University, P. O. Box 523, S-751 20 Uppsala, Sweden, and Department of Chemistry/Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden
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71
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Wilson GJ, Arnold DP. Time-dependent density functional molecular orbital and excited state calculations on bis(porphyrinyl)butadiynes in the monocationic, neutral, monoanionic, and dianionic oxidation states. J Phys Chem A 2007; 109:6104-13. [PMID: 16833948 DOI: 10.1021/jp0507041] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a theoretical study of the multiple oxidation states (1+, 0, 1-, and 2-) of a meso,meso-linked diporphyrin, namely bis[10,15,20-triphenylporphyrinatozinc(II)-5-yl]butadiyne (4), using Time-Dependent Density Functional Theory (TDDFT). The origin of electronic transitions of singlet excited states is discussed in comparison to experimental spectra for the corresponding oxidation states of the close analogue bis[10,15,20-tris[3',5'-di-tert-butylphenyl]porphyrinatozinc(II)-5-yl]butadiyne (3). The latter were measured in previous work under in situ spectroelectrochemical conditions. Excitation energies and orbital compositions of the excited states were obtained for these large delocalized aromatic radicals, which are unique examples of organic mixed-valence systems. The radical cations and anions of butadiyne-bridged diporphyrins such as 3 display characteristic electronic absorption bands in the near-IR region, which have been successfully predicted with use of these computational methods. The radicals are clearly of the "fully delocalized" or Class III type. The key spectral features of the neutral and dianionic states were also reproduced, although due to the large size of these molecules, quantitative agreement of energies with observations is not as good in the blue end of the visible region. The TDDFT calculations are largely in accord with a previous empirical model for the spectra, which was based simplistically on one-electron transitions among the eight key frontier orbitals of the C4 (1,4-butadiyne) linked diporphyrins.
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Affiliation(s)
- Gregory J Wilson
- School of Physical and Chemical Sciences, Queensland University of Technology, G.P.O. Box 2434, Brisbane, Australia 4001
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72
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Deperasińska I, Zehnacker A, Lahmani F, Borowicz P, Sepioł J. Fluorescence Studies of Terrylene in a Supersonic Jet: Indication of A Dark Electronic State Below the Allowed Transition. J Phys Chem A 2007; 111:4252-8. [PMID: 17447744 DOI: 10.1021/jp070337o] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Jet-cooled terrylene has been studied in helium buffer gas using a pulsed nozzle by means of laser-induced fluorescence. Fluorescence excitation and two-color depletion experiments (resulting in hole burning spectra) are presented. Analysis of the spectra leads to the conclusion that another excited electronic state is present in the vicinity of the allowed 1B1u state. Assuming (according to previous literature suggestions Karabunarliev, S.; Baumgarten, M.; Müllen, K. J. Phys. Chem. A 1998, 102, 7029) that this dark state is the 21Ag state, we discuss the vibrational structure of the fluorescence excitation spectrum in terms of two manifolds of vibronic states belonging to Sd(21Ag) and S1(1B1u) states. The anomalous shift between excitation and dispersed fluorescence spectra observed earlier for terrylene in a neon matrix is discussed as a consequence of terrylene electronic relaxation to the low-energy dark state.
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Affiliation(s)
- I Deperasińska
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
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73
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74
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Ortiz RP, Osuna RM, Hernandez V, Navarrete JTL, Vercelli B, Zotti G, Sumerin VV, Balenkova ES, Nenajdenko VG. Push-pull bithienyl chromophore with an unusual transverse path of conjugation. J Phys Chem A 2007; 111:841-51. [PMID: 17266224 DOI: 10.1021/jp0666176] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis, structure, and electronic properties of a novel cross-conjugated 10H-bisthienodithiocin-10-dicyanoethylene are reported. The X-ray single-crystal structure of the compound reveals a nonplanar conformation. The FT-IR and FT-Raman spectra of the compound show a great resemblance, which is a spectroscopic observation common to many push-pull systems. The UV-vis spectrum in CHCl3 displays a strong absorption at 370 nm accompanied by a shoulder at 430 nm so that the optical gap is 2.88 eV. On the other hand, the electrochemical gap amounts to 2.38 V. DFT and TDDFT quantum chemical calculations, at the B3LYP/6-31G** level, have been also performed to (i) determine the minimum-energy molecular structure, (ii) gain knowledge about the equilibrium atomic charges distribution, the topologies, and absolute energies of the frontier molecular orbitals around the gap and about the molecular vibrations which give rise to the most outstanding Raman bands experimentally evidenced, and (iii) to analyze the nature of the vertical one-electron excitations associated to the strongest UV-vis absorptions.
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75
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Kumar A, Sevilla MD. Photoexcitation of dinucleoside radical cations: a time-dependent density functional study. J Phys Chem B 2007; 110:24181-8. [PMID: 17125390 PMCID: PMC2526166 DOI: 10.1021/jp064524i] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The excited states of dinucleoside phosphates (dGpdG, dApdA, dApdT, TpdA, and dGpdT) in their cationic radical states were studied with time-dependent density functional theory (TD-DFT). The ground-state geometries of all the dinucleoside phosphate cation radicals considered, in their base stacked conformation, were optimized with the B3LYP/6-31G(d) method. Further, to take into account the effect of the aqueous environment surrounding the dinucleoside phosphates, the polarized continuum model (PCM) was considered and the excitation energies were computed by using the TD-B3LYP/6-31G(d) method. From this study, we find that the first transition in all the dinucleoside molecules involves hole transfer from base to base. dG*+pdG and dApdA*+ were found to have substantially lower first transition energies than others with two different DNA bases. Higher energy transitions involve base to sugar as well as base to base hole transfer. The calculated TD-B3LYP/6-31G(d) transition energies are in good agreement with previous calculations with CASSCF/CAS-PT2 level of theory. This TD-DFT work supports the experimental findings that sugar radicals formed upon photoexcitation of G*+ in gamma-irradiated DNA and suggests an explanation for the wavelength dependence found.
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76
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Ernstorfer R, Gundlach L, Felber S, Storck W, Eichberger R, Willig F. Role of Molecular Anchor Groups in Molecule-to-Semiconductor Electron Transfer. J Phys Chem B 2006; 110:25383-91. [PMID: 17165985 DOI: 10.1021/jp064436y] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The dynamics of heterogeneous electron transfer (ET) from the polycyclic aromatic chromophore perylene to nanostructured TiO2 anatase was investigated for two different anchor groups with transient absorption spectroscopy in an ultrahigh vacuum. Data from ultraviolet photoelectron spectroscopy and from linear absorption spectroscopy showed that the donor state of the chromophore was located around 900 meV above the lower edge of the conduction band. With the wide band limit fulfilled the rate of the heterogeneous ET reaction was only controlled by the strength of the electronic coupling and not reduced by Franck-Condon factors. Two different time constants for the electron transfer, i.e., 13 and 28 fs, were measured with carboxylic acid and phosphonic acid as the respective anchor groups. The difference in the ET time constants was explained with the different extension of the donor orbital onto the respective anchor group to reach the empty electronic states of the semiconductor. The time constants were extracted by means of a simple rate equation model. The validity of applying this model on this ultrafast time scale was verified by comparing the rate equation model with an optical Bloch equation model.
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Affiliation(s)
- Ralph Ernstorfer
- Dynamics of Interfacial Reactions SE 4, Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109 Berlin, Germany.
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77
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Wang L, Willig F, May V. Theory of ultrafast photoinduced heterogeneous electron transfer. MOLECULAR SIMULATION 2006. [DOI: 10.1080/08927020600883285] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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78
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Hajgató B, Deleuze MS, Ohno K. Aromaticity of Giant Polycyclic Aromatic Hydrocarbons with Hollow Sites: Super Ring Currents in Super-Rings. Chemistry 2006; 12:5757-69. [PMID: 16718724 DOI: 10.1002/chem.200501321] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We present a systematic theoretical study based on semi-empirical, Hartree-Fock (HF), and density functional theory (DFT) models of a series of polycyclic aromatic hydrocarbons (PAHs) that exhibit hollow sites. In this study we focus particularly on the magnetic criteria of aromaticity, namely (1)H NMR and nucleus-independent chemical shifts (NICS), and on their relationships with other electronic properties. The computed shifts and NICS indices indicate that an external magnetic field induces exceptionally strong ring currents in even-layered PAH doughnuts, in particular in the layer directly adjacent to the central hole of double-layered compounds. These exceptionally strong ring currents also correlate with particularly small HOMO-LUMO gaps and electronic excitation energies and to abnormally high polarizabilities, indicating in turn that these compounds have a more pronounced metallic character. Comparison is made with further depictions of aromaticity in these systems and in [18]-[66]annulene rings by employing topological, structural, and energetic criteria.
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Affiliation(s)
- Balázs Hajgató
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki, Aza-aoba, Aoba-ku, Sendai 980-8578, Japan
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79
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Gudipati MS, Allamandola LJ. Double Ionization of Quaterrylene (C40H20) in Water-Ice at 20 K with Lyα (121.6 nm) Radiation. J Phys Chem A 2006; 110:9020-4. [PMID: 16836467 DOI: 10.1021/jp061416n] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polycyclic aromatic hydrocarbon (PAH) molecules undergo facile ionization in cryogenic water-ices resulting in near quantitative conversions of neutral molecules to the corresponding singly charged radical cations. Here we report, for the first time, the production and stabilization of a doubly ionized, closed shell PAH in water-ice. The large PAH quaterrylene (QTR, C40H20) is readily photoionized and stabilized as QTR 2+ in a water-ice matrix at 20 K. The kinetic analysis of photolysis shows that the QTR 2+ is formed at the expense of QTR +, not directly from QTR. The long-axis polarized S1-S0 (1(1)B(3u) <-- 1(1)Ag) transition for QTR 2+ falls at 1.59 eV (782 nm). TD-DFT calculations at the B3LYP level predict that this transition falls at 1.85 eV (670 nm) for free gas-phase QTR 2+, within the 0.3 eV uncertainty associated with these calculations. This red shift of 0.26 eV is quite similar to the 0.24 eV red shift between the TD-DFT computational prediction for the lowest energy transition for QTR + (1.68 eV) and its value in a water matrix (1.44 eV). These results suggest that multiple photoionization of such large PAHs in water-ice can be an efficient process in general.
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Affiliation(s)
- Murthy S Gudipati
- NASA Ames Research Center, Mail Stop 245-6, Moffett Field, California 94035, USA.
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80
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Hata T, Murakami T, Shibuya H, Ono Y. Improved CNDO/S calculation of electronic spectra of organic compounds. I. New CNDO/S calculation by using an improved method of one-center electron repulsion integral. Chem Pharm Bull (Tokyo) 2006; 54:646-52. [PMID: 16651759 DOI: 10.1248/cpb.54.646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The NM-gamma CNDO/S program previously developed by our group was modified by the introduction of a new one-center electron repulsion integral gamma(AA)(new) approximation, namely, the gamma(AA)(new)-CNDO/S method. The value of this gamma(AA)(new) was evaluated according to the product values of the coefficient C with the gamma(AA) value proposed in our previous paper. This method using a new gamma(AA) was also found to improve the two-center electron repulsion integral gamma(AB) value with respect to the chemical softness proposed by Nishimoto and co-workers, together with the difference between HOMO and LUMO orbital energies. The results calculated by the present improved gamma(AA)(new)-CNDO/S method demonstrated that not only the calculated absorption maxima wavelengths and ionization potentials, but also the order and the assignment of orbitals coincided very well with those based on the results of experiments investigating a variety of polyenes, cyanynes, and polycyclic aromatic hydrocarbons.
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Affiliation(s)
- Toshiyuki Hata
- Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Sanzo, Gakuen-chou, Fukuyama, Hiroshima 729-0292, Japan
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81
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Kokkin DL, Schmidt TW. On the Electronic Properties of Dehydrogenated Polycyclic Aromatic Hydrocarbons. J Phys Chem A 2006; 110:6173-7. [PMID: 16671689 DOI: 10.1021/jp057441v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electronic excited-state properties of a series of dehydrogenated polycyclic aromatic hydrocarbons from phenyl through to decacyl are reported. The radicals were investigated by use of time-dependent density functional theory in conjunction with the B3LYP functional. The pi and n orbitals were seen to converge in energy as the system increased in size, yet all radicals were found to have A' ground states. In addition to the study of the electronic state symmetries, the excited-state transitions and oscillator strengths were investigated with the resulting transitions found within the visible region of the spectrum, placing these radicals in the large group of candidate carriers of the diffuse interstellar bands.
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Affiliation(s)
- Damian L Kokkin
- School of Chemistry, University of Sydney, NSW 2006, Australia
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82
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Kloppmann E, Becker T, Ullmann GM. Electrostatic potential at the retinal of three archaeal rhodopsins: implications for their different absorption spectra. Proteins 2006; 61:953-65. [PMID: 16247786 DOI: 10.1002/prot.20744] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The color tuning mechanism of the rhodopsin protein family has been in the focus of research for decades. However, the structural basis of the tuning mechanism in general and of the absorption shift between rhodopsins in particular remains under discussion. It is clear that a major determinant for spectral shifts between different rhodopsins are electrostatic interactions between the chromophore retinal and the protein. Based on the Poisson-Boltzmann equation, we computed and compared the electrostatic potential at the retinal of three archaeal rhodopsins: bacteriorhodopsin (BR), halorhodopsin (HR), and sensory rhodopsin II (SRII) for which high-resolution structures are available. These proteins are an excellent test case for understanding the spectral tuning of retinal. The absorption maxima of BR and HR are very similar, whereas the spectrum of SRII is considerably blue shifted--despite the structural similarity between these three proteins. In agreement with their absorption maxima, we find that the electrostatic potential is similar in BR and HR, whereas significant differences are seen for SRII. The decomposition of the electrostatic potential into contributions of individual residues, allowed us to identify seven residues that are responsible for the differences in electrostatic potential between the proteins. Three of these residues are located in the retinal binding pocket and have in fact been shown to account for part of the absorption shift between BR and SRII by mutational studies. One residue is located close to the beta-ionone ring of retinal and the remaining three residues are more than 8 A away from the retinal. These residues have not been discussed before, because they are, partly because of their location, no obvious candidates for the spectral shift among BR, HR, and SRII. However, their contribution to the differences in electrostatic potential is evident. The counterion of the Schiff base, which is frequently discussed to be involved in the spectral tuning, does not contribute to the dissimilarities between the electrostatic potentials.
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Affiliation(s)
- Edda Kloppmann
- Structural Biology/Bioinformatics, University of Bayreuth, Bayreuth, Germany
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83
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Persson P, Lundqvist MJ, Ernstorfer R, Goddard WA, Willig F. Quantum Chemical Calculations of the Influence of Anchor-Cum-Spacer Groups on Femtosecond Electron Transfer Times in Dye-Sensitized Semiconductor Nanocrystals. J Chem Theory Comput 2006; 2:441-51. [DOI: 10.1021/ct050141x] [Citation(s) in RCA: 236] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Persson
- Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden, Materials and Process Simulation Center, Beckman Institute 13974, California Institute of Technology, Pasadena, California 91125, and Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin, Germany
| | - M. J. Lundqvist
- Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden, Materials and Process Simulation Center, Beckman Institute 13974, California Institute of Technology, Pasadena, California 91125, and Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin, Germany
| | - R. Ernstorfer
- Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden, Materials and Process Simulation Center, Beckman Institute 13974, California Institute of Technology, Pasadena, California 91125, and Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin, Germany
| | - W. A. Goddard
- Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden, Materials and Process Simulation Center, Beckman Institute 13974, California Institute of Technology, Pasadena, California 91125, and Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin, Germany
| | - F. Willig
- Department of Quantum Chemistry, Uppsala University, Box 518, SE-751 20 Uppsala, Sweden, Materials and Process Simulation Center, Beckman Institute 13974, California Institute of Technology, Pasadena, California 91125, and Hahn-Meitner-Institut, Glienickerstrasse 100, D-14109 Berlin, Germany
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84
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Berlin A, Grimoldi S, Zotti G, Osuna RM, Ruiz Delgado MC, Ortiz RP, Casado J, Hernandez V, López Navarrete JT. Synthesis and Characterization of a Novel Terthiophene-Based Quinodimethane Bearing a 3,4-Ethylenedioxythiophene Central Unit. J Phys Chem B 2005; 109:22308-18. [PMID: 16853905 DOI: 10.1021/jp054204j] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and a combined spectroscopic and density functional theoretical characterization of a 3',4'-ethylenedioxy-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene analogue of 7,7,8,8-tetracyanoquinodimethane (TCNQ) are presented. Electrochemical data show that this novel trimer can be both reversibly reduced and oxidized at relatively low potentials. Quantum-chemical calculations show that the compound exhibits a quinoidal structure in its ground electronic state and that a certain degree of intramolecular charge transfer takes place from the central terthienyl moiety toward both =C(CN)2 end-caps. Therefore, the amphoteric redox behavior of this novel material can be related to the coexistence of an electron-impoverished terthienyl core endowed by two electron-enriched =C(CN)2 substituents. The UV-vis spectrum is dominated by the appearance of a strong absorption near 660 nm, attributable to the highest occupied molecular orbital (HOMO) --> lowest unoccupied molecular orbital (LUMO) pi-pi electronic transition of the terthienyl spine on the basis of time-dependent density functional theory (DFT) computations. The DFT calculations performed on the minimum-energy molecular geometry about the equilibrium atomic charge distribution, topologies, and energies of the frontier orbitals around the gap and about the Raman-active vibrations associated with the strongest Raman features are also consistent with a rather effective pi-electron conjugation and the partial degree of intramolecular charge transfer mentioned above. Our study reveals this novel heteroquinoid trimer could act as a promising candidate in organic field-effect transistor (OFET) applications.
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Affiliation(s)
- Anna Berlin
- Istituto CNR di Scienze e Tecnologie Molecolari, via C. Golgi 19, 20133 Milano, Italy
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85
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Lewis FD, Zhang L, Zuo X. Orientation control of fluorescence resonance energy transfer using DNA as a helical scaffold. J Am Chem Soc 2005; 127:10002-3. [PMID: 16011355 DOI: 10.1021/ja0524402] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The efficiency of fluorescence resonance energy transfer (FRET) between two chromophores positioned at opposite ends of DNA base pair domains has been investigated. The base pair domain serves as a helical scaffold which defines both the distance between chromophores and the dihedral angle between their electronic transition dipole moments, each incremental base pair increasing the distance and stepping the dihedral angle. Fluorescence quantum yields and lifetimes have been determined for both the donor and acceptor chromophores. The experimental data are found to be in excellent accord with an oriented dipole model, rather than with the averaged dipole model conventionally assumed for FRET.
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Affiliation(s)
- Frederick D Lewis
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
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86
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Dreuw A, Head-Gordon M. Single-Reference ab Initio Methods for the Calculation of Excited States of Large Molecules. Chem Rev 2005; 105:4009-37. [PMID: 16277369 DOI: 10.1021/cr0505627] [Citation(s) in RCA: 1840] [Impact Index Per Article: 96.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andreas Dreuw
- Institut für Physikalische und Theoretische Chemie, Johann Wolfgang Goethe-Universität, Marie Curie-Strasse 11, 60439 Frankfurt am Main, Germany.
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87
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Amicangelo JC. Theoretical Study of the Benzene Excimer Using Time-Dependent Density Functional Theory. J Phys Chem A 2005; 109:9174-82. [PMID: 16332027 DOI: 10.1021/jp053445o] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A theoretical characterization of the potential energy surfaces of the singlet benzene excimer states derived from the B2u monomer excited state has been performed using time-dependent density functional theory. The excited-state potential energy surfaces were initially characterized by computations along the parallel and perpendicular intermolecular translational coordinates. These calculations predict that the lowest excited state for parallel translation is bound with a minimum at 3.15 angstroms and with a binding energy of 0.46 eV, while the perpendicular translational coordinate was essentially found to be a repulsive state. At the calculated minimum distance, the effect of in-plane rotation, out-of-plane rotation, and slipped-parallel translation were examined. The rotational calculations predict that deviations from the D6h geometry lead to a destabilization of the excimer state; however, small angular variations in the range of 0 degrees -10 degrees are predicted to be energetically feasible. The slipped-parallel translational calculations also predict a destabilizing effect on the excimer state and were found to possess barriers to this type of dissociation in the range of 0.50-0.61 eV. When compared to experimentally determined values for the benzene excimer energetics, the calculated values were found to be in semiquantitative agreement. Overall, this study suggests that the time-dependent density functional theory method can be used to characterize the potential energy surfaces and the energetics of aromatic excimers with reasonable accuracy.
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Affiliation(s)
- Jay C Amicangelo
- School of Science, Penn State Erie, The Behrend College, 5091 Stattion Road, Erie, Pennsylvania 16563-0203, USA
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88
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Wang L, Ernstorfer R, Willig F, May V. Absorption Spectra Related to Heterogeneous Electron Transfer Reactions: The Perylene TiO2 System. J Phys Chem B 2005; 109:9589-95. [PMID: 16852154 DOI: 10.1021/jp0500539] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Linear absorption spectra of dye-semiconductor systems (perylene attached to nanostructured TiO2) are studied theoretically and experimentally. The systems show ultrafast photoinduced heterogeneous electron transfer (HET). By applying a time-dependent formulation of the absorbance, the theoretical analysis of the measured data is carried out. The respective electron-vibrational wave packet propagation fully accounts for the electronic coupling to the conduction band continuum of TiO2 and is based on a single-reaction-coordinate model (corresponding to a perylene in-plane C-C stretching vibration with a quantum energy of 1370 cm(-1)). By the insertion of different bridge-anchor groups, the electronic coupling responsible for HET is varied. The dye absorbance in a solvent and the trends in the line broadening of the vibrational progression due to the coupling to the conduction band continuum are reproduced for all investigated types of bridge-anchor groups. HET rates deduced from the calculations on the absorbance displaying line broadenings follow the qualitative trend obtained from transient absorption spectra.
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Affiliation(s)
- Luxia Wang
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany
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89
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Tan X, Salama F. Cavity ring-down spectroscopy and theoretical calculations of the S1(B3u1)←S0(Ag1) transition of jet-cooled perylene. J Chem Phys 2005; 122:84318. [PMID: 15836050 DOI: 10.1063/1.1851502] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As part of our long-term program to test the diffuse interstellar band-polycyclic aromatic hydrocarbon hypothesis, we have investigated the S(1)<--S(0) electronic transition of neutral perylene (C(20)H(12)) in a combined experimental and theoretical study. Jet-cooled perylene was prepared with a pulsed discharge slit nozzle and detected by cavity ring-down spectroscopy. A number of vibronic features were observed in the 24 000-24 900 cm(-1) spectral range. Density functional and ab initio calculations were performed to determine the geometries, harmonic vibrational frequencies, and normal coordinates of both the S(0) and S(1) electronic states. A rotational temperature of 52+/-5 K was derived from a rotational contour analysis of the vibronic band associated with the 0-0 transition. A Franck-Condon treatment was carried out to calculate the vibronic spectrum of the S(1)<--S(0) transition. A good agreement was found between the calculated and the experimental spectra. A vibrational assignment is proposed and six normal modes are identified. The contribution of neutral compact polycyclic aromatic hydrocarbons to the diffuse interstellar bands is briefly discussed.
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Affiliation(s)
- Xiaofeng Tan
- Space Science Division, NASA Ames Research Center, Mail Stop 245-6, Moffett Field, CA 94035-1000, USA.
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90
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Furche F, Rappoport D. Density Functional Methods for Excited States: Equilibrium Structure and Electronic Spectra. THEORETICAL AND COMPUTATIONAL CHEMISTRY 2005. [DOI: 10.1016/s1380-7323(05)80020-2] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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91
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Dierksen M, Grimme S. The Vibronic Structure of Electronic Absorption Spectra of Large Molecules: A Time-Dependent Density Functional Study on the Influence of “Exact” Hartree−Fock Exchange. J Phys Chem A 2004. [DOI: 10.1021/jp047289h] [Citation(s) in RCA: 291] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marc Dierksen
- Theoretische Organische Chemie, Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Stefan Grimme
- Theoretische Organische Chemie, Organisch-Chemisches Institut der Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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92
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Banisaukas J, Szczepanski J, Vala M, Hirata S. Vibrational and Electronic Absorption Spectroscopy of 2,3-Benzofluorene and Its Cation. J Phys Chem A 2004. [DOI: 10.1021/jp031163n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John Banisaukas
- Department of Chemistry and Center for Chemical Physics, University of Florida, Gainesville, Florida 32611-7200
| | - Jan Szczepanski
- Department of Chemistry and Center for Chemical Physics, University of Florida, Gainesville, Florida 32611-7200
| | - Martin Vala
- Department of Chemistry and Center for Chemical Physics, University of Florida, Gainesville, Florida 32611-7200
| | - So Hirata
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352
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93
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Zhou Z, Steigerwald M, Hybertsen M, Brus L, Friesner RA. Electronic Structure of Tubular Aromatic Molecules Derived from the Metallic (5,5) Armchair Single Wall Carbon Nanotube. J Am Chem Soc 2004; 126:3597-607. [PMID: 15025489 DOI: 10.1021/ja039294p] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
All-electron static and time-dependent DFT electronic calculations, with complete geometrical optimization, are performed on tubular molecules up to C(210)H(20) that are finite sections of the (5,5) metallic single wall carbon nanotube with hydrogen termination at the open ends. We find pronounced C-C bond reconstruction at the tube ends; this initiates bond alternation that propagates into the tube centers. For the especially low band gap molecules C(120)H(20), C(150)H(20), and C(180)H(20), alternation increases, and a second nearly isoenergic structural isomer of different alternation is found. A small residual C-C bond alternation and band gap may be present in the infinite tube. The van Hove band gap forms quickly with length, while the metallic Fermi point (at the crossing of linear bands) forms very slowly with length. There are no end-localized states at energies near the Fermi energy. The HOMO-LUMO gap and the lowest singlet excited state, whose energies show a periodicity with length as previously calculated, are optically forbidden. However, each molecule shows an intense visible "charge transfer" transition, not present in the infinite tube, whose energy varies smoothly with length; this transition should be an identifying signature for these molecules. The static axial polarizability per unit length increases rapidly with N as the "charge transfer" transition moves into the infrared; this indicates increasing metallic character. However, the ionization potential, electron affinity, chemical hardness, and relative energetic stability all show the length periodicity seen in the HOMO-LUMO gap, in contrast to the optical "charge transfer" transition and the static axial polarizability. These periodicities, due to a one-dimensional quantum size effect as originally modeled by Coulson in 1938, nevertheless cancel in the calculated Fermi energy, which varies smoothly toward a predicted bulk work function near 3.9 eV. A detailed study of C(190)H(20) with up to eight extra electrons or holes shows the total energy is closely fit by a simple classical charging model, as is commonly applied to metallic clusters.
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Affiliation(s)
- Zhiyong Zhou
- Department of Chemistry, Materials Research Science and Engineering Center, Columbia University, New York, New York 10027, USA
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94
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Hajgató B, Ohno K. Novel series of giant polycyclic aromatic hydrocarbons: electronic structure and aromaticity. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.01.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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95
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Thompson AL, Gaab KM, Xu J, Bardeen CJ, Martínez TJ. Variable Electronic Coupling in Phenylacetylene Dendrimers: The Role of Förster, Dexter, and Charge-Transfer Interactions. J Phys Chem A 2004. [DOI: 10.1021/jp030953u] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexis L. Thompson
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801
| | - Kevin M. Gaab
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801
| | - Jianjun Xu
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801
| | - Christopher J. Bardeen
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801
| | - Todd J. Martínez
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801
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96
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Wang L, May V. Laser pulse control of ultrafast heterogeneous electron transfer: A computational study. J Chem Phys 2004; 121:8039-49. [PMID: 15485268 DOI: 10.1063/1.1796274] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Laser pulse control of the photoinduced 90 fs charge injection from perylene into the conduction band of TiO2 is studied theoretically. The approach accounts for the electronic-ground state of the dye, the first excited state, the ionized state formed after charge injection, and the continuum of the electronic states in the conduction band, all defined vs a single reaction coordinate. To address different control tasks optimal control theory is combined with a full quantum dynamical description of the electron-vibrational motion accompanying the charge injection process. First it is proved in which way the charge injection time can be changed by tailored laser pulses. In a second step a pump-dump scheme from the perylene ground state to the first excited electronic state and back to the ground state is discussed. Because of the strong coupling of the excited perylene state to the band continuum of TiO2 this control task is more suited to an experimental test than the direct control of the charge injection.
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Affiliation(s)
- Luxia Wang
- Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany
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97
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Zhou Z, Friesner RA, Brus L. Electronic Structure of 1 to 2 nm Diameter Silicon Core/Shell Nanocrystals: Surface Chemistry, Optical Spectra, Charge Transfer, and Doping. J Am Chem Soc 2003; 125:15599-607. [PMID: 14664607 DOI: 10.1021/ja036443v] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Static and time-dependent density functional calculations, geometrically optimized and including all electrons, are described for silicon nanocrystals as large as Si(87)H(76), which contains 163 atoms. We explore and predict the effect that different sp(3) passivation schemes-F or H termination, thin oxide shell, or alkane termination-have on the HOMO and LUMO, on the optical spectra, and on electron transfer properties. Electronegativity comparisons are a useful guide in understanding the observed deviation from the simple quantum size effect model. Nanocrystals containing Al or P impurity atoms, either on the surface or in the interior, are explored to understand electrical doping in strongly quantum-confined nanocrystals. Surface dangling bonds are found to participate in internal charge transfer with P atom dopant electrons.
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Affiliation(s)
- Zhiyong Zhou
- Chemistry Department, Columbia University, New York, NY 10027, USA
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