1
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Prajapati B, Ambhore MD, Dang DK, Chmielewski PJ, Lis T, Gómez-García CJ, Zimmerman PM, Stępień M. Tetrafluorenofulvalene as a sterically frustrated open-shell alkene. Nat Chem 2023; 15:1541-1548. [PMID: 37783726 PMCID: PMC10624625 DOI: 10.1038/s41557-023-01341-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 09/04/2023] [Indexed: 10/04/2023]
Abstract
Electronic and steric effects are known to greatly influence the structure, characteristics and reactivity of organic compounds. A typical π bond is weakened by oxidation (corresponding to the removal of electrons from bonding orbitals), by reduction (through addition of electrons to antibonding orbitals) and by unpairing of the bonding electrons, such as in the triplet state. Here we describe tetrafluorenofulvalene (TFF), a twisted, open-shell alkene for which these general rules do not hold. Through the synthesis, experimental characterization and computational analysis of its charged species spanning seven redox states, the central alkene bond in TFF is shown to become substantially stronger in the tri- and tetraanion, generated by chemical reduction. Furthermore, although its triplet state contains a weaker alkene bond than the singlet, in the quintet state its bond order increases substantially, yielding a flatter structure. This behaviour originates from the doubly bifurcated topology of the underlying spin system and can be rationalized by the balancing effects of benzenoid aromaticity and spin pairing.
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Affiliation(s)
| | | | - Duy-Khoi Dang
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | | | - Tadeusz Lis
- Wydział Chemii, Uniwersytet Wrocławski, Wrocław, Poland
| | - Carlos J Gómez-García
- Departamento de Química Inorgánica and Instituto de Ciencia Molecular, Universidad de Valencia, Paterna, Spain
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | - Marcin Stępień
- Wydział Chemii, Uniwersytet Wrocławski, Wrocław, Poland.
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2
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Zähringer TJB, Wienhold M, Gilmour R, Kerzig C. Direct Observation of Triplet States in the Isomerization of Alkenylboronates by Energy Transfer Catalysis. J Am Chem Soc 2023; 145:21576-21586. [PMID: 37729087 DOI: 10.1021/jacs.3c07678] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Alkenylboronates are versatile building blocks for stereocontrolled synthesis owing to the traceless nature of the boron group that can be leveraged to achieve highly selective geometric isomerization. Using thioxanthone as an inexpensive photocatalyst, the photoisomerization of these species continues to provide an expansive platform for stereodivergent synthesis, particularly in the construction of bioactive polyenes. Although mechanistic investigations are consistent with light-driven energy transfer, direct experimental evidence remains conspicuously absent. Herein, we report a rigorous mechanistic investigation using two widely used alkenylboronates alongside relevant reference compounds. Through the combination of irradiation experiments, transient absorption spectroscopic studies, kinetic modeling, and DFT calculations with all isomers of the model compounds, it has been possible to unequivocally detect and characterize the perpendicular triplet generated by energy transfer. Our results serve not only as a blueprint for mechanistic studies that are challenging with organic sensitizers, but these guidelines delineated have also enabled the development of more sustainable reaction conditions: for the first time, efficient organocatalytic isomerization under sunlight irradiation has become feasible.
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Affiliation(s)
- Till J B Zähringer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Max Wienhold
- Organisch-Chemisches Institut,Westfälische Wilhelms-Universität Münster, Correnstraβe 36, 48149 Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut,Westfälische Wilhelms-Universität Münster, Correnstraβe 36, 48149 Münster, Germany
- Cells in Motion (CiM) Interfaculty Center, Röntgenstraβe 16, 48149 Münster, Germany
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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3
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Sarkar SK, Upul Ranaweera RAA, Merugu R, Abdelaziz NM, Robinson J, Day HA, Krause JA, Gudmundsdottir AD. Comparison of the Photochemistry of Acyclic and Cyclic 4-(4-Methoxy-phenyl)-4-oxo-but-2-enoate Ester Derivatives. J Phys Chem A 2020; 124:7346-7354. [PMID: 32786978 DOI: 10.1021/acs.jpca.0c04319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To clarify the cis-trans isomerization mechanism of simple alkenes on the triplet excited state surface, the photochemistry of acyclic and cyclic vinyl ketones with a p-methoxyacetophenone moiety as a built-in triplet sensitizer (1 and 2, respectively) was compared. When irradiated, ketone 1 produces its cis-isomer, whereas ketone 2 does not yield any photoproducts. Laser flash photolysis of ketone 1 yields a transient spectrum with λmax ∼ 400 nm (τ ∼ 125 ns). This transient is assigned to the first triplet excited state (T1) of 1, which presumably decays to form a triplet biradical (1BR) that is shorter lived than the triplet ketone. In comparison, laser flash photolysis of 2 reveals two transients (τ ∼ 20 and 440 ns), which are assigned to T1 of 2 and triplet biradical 2BR, respectively. Density functional theory calculations support the characterization of the triplet excited states and the biradical intermediates formed upon irradiation of ketones 1 and 2 and allow a comparison of the physical properties of the biradical intermediates. As the biradical centers in 2BR are stabilized by conjugation, 2BR is more rigid than 1BR. Therefore, the longer lifetime of 2BR can be attributed to less-efficient intersystem crossing to the ground state.
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Affiliation(s)
- Sujan K Sarkar
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | | | - Rajkumar Merugu
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Nayera M Abdelaziz
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Jendai Robinson
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Heidi A Day
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Jeanette A Krause
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
| | - Anna D Gudmundsdottir
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States
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4
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Wu JI, Eikema Hommes NJ, Lenoir D, Bachrach SM. The quest for a triplet ground‐state alkene: Highly twisted C═C double bonds. J PHYS ORG CHEM 2019. [DOI: 10.1002/poc.3965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Judy I. Wu
- Department of Chemistry University of Houston Houston TX USA
| | - Nico J.R. Eikema Hommes
- Computer Chemistry Center, Department of Chemistry and Pharmacy Friedrich‐Alexander University Erlangen‐Nürnberg Erlangen Germany
| | - Dieter Lenoir
- Helmholtz Center München, Molecular Exposomics Neuherberg Germany
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5
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Babaei A, Rakstys K, Guelen S, Fallah Hamidabadi V, La-Placa MG, Martínez-Sarti L, Sessolo M, Joel HA, Gaudin OPM, Schanen V, Nazeeruddin MK, Bolink HJ. Solution processed organic light-emitting diodes using a triazatruxene crosslinkable hole transporting material. RSC Adv 2018; 8:35719-35723. [PMID: 35547926 PMCID: PMC9087953 DOI: 10.1039/c8ra07184e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/10/2018] [Indexed: 11/21/2022] Open
Abstract
A cross-linkable triazatruxene that leads to insoluble films upon thermal annealing at temperatures compatible with flexible substrates is presented. The films were used as the hole transporting and electron blocking layer in partially solution processed phosphorescent organic light-emitting diodes, reaching power conversion efficiencies of 24 lm W−1, an almost 50% improvement compared to the same OLEDs without the cross-linkable hole transporting layer. A cross-linkable triazatruxene that leads to insoluble films upon thermal annealing at temperatures compatible with flexible substrates is presented.![]()
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Affiliation(s)
- Azin Babaei
- Instituto de Ciencia Molecular
- Universidad de Valencia
- Paterna
- Spain
| | - Kasparas Rakstys
- Group for Molecular Engineering of Functional Materials
- Ecole Polytechnique Federale de Lausanne
- CH-1951 Sion
- Switzerland
| | - Simon Guelen
- Centre de Recherche Solvay
- 69190 Saint-Fons
- France
| | | | | | | | - Michele Sessolo
- Instituto de Ciencia Molecular
- Universidad de Valencia
- Paterna
- Spain
| | - Huckaba Aron Joel
- Group for Molecular Engineering of Functional Materials
- Ecole Polytechnique Federale de Lausanne
- CH-1951 Sion
- Switzerland
| | | | | | - Mohammad Khaja Nazeeruddin
- Group for Molecular Engineering of Functional Materials
- Ecole Polytechnique Federale de Lausanne
- CH-1951 Sion
- Switzerland
| | - Henk J. Bolink
- Instituto de Ciencia Molecular
- Universidad de Valencia
- Paterna
- Spain
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6
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Kostenko A, Tumanskii B, Karni M, Inoue S, Ichinohe M, Sekiguchi A, Apeloig Y. Observation of a Thermally Accessible Triplet State Resulting from Rotation around a Main-Group π Bond. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506291] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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7
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Kostenko A, Tumanskii B, Karni M, Inoue S, Ichinohe M, Sekiguchi A, Apeloig Y. Observation of a Thermally Accessible Triplet State Resulting from Rotation around a Main-Group π Bond. Angew Chem Int Ed Engl 2015; 54:12144-8. [DOI: 10.1002/anie.201506291] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 07/27/2015] [Indexed: 11/11/2022]
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8
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Sriyarathne HDM, Thenna-Hewa KRS, Scott T, Gudmundsdottir AD. Formation and Direct Detection of Non-Conjugated Triplet 1,2-Biradical from β,γ-Vinylarylketone. Aust J Chem 2015. [DOI: 10.1071/ch15401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Laser flash photolysis of 2-methyl-1-phenylbut-3-en-1-one (1) conducted at irradiation wavelengths of 266 and 308 nm results in the formation of triplet 1,2-biradical 2 that has λmax at 370 and 480 nm. Biradical 2 is formed with a rate constant of 1.1 × 107 s–1 and decays with a rate constant of 2.3 × 105 s–1. Isoprene-quenching studies support the notion that biradical 2 is formed by energy transfer from the triplet-excited state of the ketone chromophore of 1. Density functional theory calculations were used to verify the characterization of triplet biradical 2 and validate the mechanism for its formation. Thus, it has been demonstrated that intramolecular sensitization of simple alkenes can be used to form triplet 1,2-biradicals with the two radical centres localized on the adjacent carbon atoms.
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9
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Ranaweera RAAU, Scott T, Li Q, Rajam S, Duncan A, Li R, Evans A, Bohne C, Toscano JP, Ault BS, Gudmundsdottir AD. Trans–Cis Isomerization of Vinylketones through Triplet 1,2-Biradicals. J Phys Chem A 2014; 118:10433-47. [DOI: 10.1021/jp504174t] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
| | - Tianeka Scott
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Qian Li
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Sridhar Rajam
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Alexander Duncan
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Rui Li
- Department
of Chemistry, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Anthony Evans
- Department
of Chemistry, John Hopkins University, Baltimore, Maryland 21218, United States
| | - Cornelia Bohne
- Department
of Chemistry, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - John P. Toscano
- Department
of Chemistry, John Hopkins University, Baltimore, Maryland 21218, United States
| | - Bruce S. Ault
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Anna D. Gudmundsdottir
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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10
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Kanawati B, Genest A, Schmitt-Kopplin P, Lenoir D. Bis-dibenzo[a.i]fluorenylidene, does it exist as stable 1,2-diradical? J Mol Model 2012; 18:5089-95. [DOI: 10.1007/s00894-012-1502-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 06/08/2012] [Indexed: 11/24/2022]
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11
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Varras PC, Zarkadis AK. Ground- and triplet excited-state properties correlation: a computational CASSCF/CASPT2 approach based on the photodissociation of allylsilanes. J Phys Chem A 2012; 116:1425-34. [PMID: 22208892 DOI: 10.1021/jp209583z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Excited-state properties, although extremely useful, are hardly accessible. One indirect way would be to derive them from relationships to ground-state properties which are usually more readily available. Herewith, we present quantitative correlations between triplet excited-state (T₁) properties (bond dissociation energy, D₀(T₁), homolytic activation energy, E(a)(T₁), and rate constant, k(r)) and the ground-state bond dissociation energy (D₀), taking as an example the photodissociation of the C-Si bond of simple substituted allylsilanes CH₂=CHC(R¹R²)-SiH₃ (R¹ and R² = H, Me, and Et). By applying the complete-active-space self-consistent field CASSCF(6,6) and CASPT2(6,6) quantum chemical methodologies, we have found that the consecutive introduction of Me/Et groups has little effect on the geometry and energy of the T₁ state; however, it reduces the magnitudes of D₀, D₀(T₁) and E(a)(T₁). Moreover, these energetic parameters have been plotted giving good linear correlations: D₀(T₁) = α₁ + β₁ · D₀, E(a)(T₁) = α₂ + β₂ · D₀(T₁), and E(a)(T₁) = α₃ + β₃ · D₀ (α and β being constants), while k(r) correlates very well to E(a)(T₁). The key factor behind these useful correlations is the validity of the Evans-Polanyi-Semenov relation (second equation) and its extended form (third equation) applied for excited systems. Additionally, the unexpectedly high values obtained for E(a)(T₁) demonstrate a new application of the principle of nonperfect synchronization (PNS) in excited-state chemistry issues.
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12
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Watts HD, Mohamed MNA, Kubicki JD. Evaluation of potential reaction mechanisms leading to the formation of coniferyl alcohol α-linkages in lignin: a density functional theory study. Phys Chem Chem Phys 2011; 13:20974-85. [DOI: 10.1039/c1cp21906e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Görner H. Photophysics and photochemistry of trans-4-nitrostilbenes and trans-2,4-dinitrostilbenes: Effect of intramolecular charge transfer. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19981020505] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Barbafina A, Latterini L, Carlotti B, Elisei F. Characterization of Excited States of Quinones and Identification of Their Deactivation Pathways. J Phys Chem A 2010; 114:5980-4. [DOI: 10.1021/jp911734x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Arianna Barbafina
- Department of Chemistry and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), via Elce di Sotto 8, Perugia 06123, Italy
| | - Loredana Latterini
- Department of Chemistry and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), via Elce di Sotto 8, Perugia 06123, Italy
| | - Benedetta Carlotti
- Department of Chemistry and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), via Elce di Sotto 8, Perugia 06123, Italy
| | - Fausto Elisei
- Department of Chemistry and Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), via Elce di Sotto 8, Perugia 06123, Italy
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15
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Saltiel J, Dmitrenko O, Pillai ZS, Klima R, Wang S, Wharton T, Huang ZN, van de Burgt LJ, Arranz J. Triplet and ground state potential energy surfaces of 1,4-diphenyl-1,3-butadiene: theory and experiment. Photochem Photobiol Sci 2008; 7:566-77. [DOI: 10.1039/b801075g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Saltiel J, Klima RF. α-Methylstilbene and the Duality of Mechanism in the Quenching of Stilbene Triplets by Molecular Oxygen†. Photochem Photobiol 2006; 82:38-42. [PMID: 15960592 DOI: 10.1562/2005-05-09-ra-521] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Spin-exchange quenching of alpha-methylstilbene triplets by molecular oxygen and by the free radical di-tert-butyl nitroxide is shown to favor the cis isomer more than does natural decay. The effect of the two quenching events is an identical 7% decrease in the fraction of perpendicular triplets that decay to the trans isomer. The conclusion that relaxed stilbene triplets reside in a shallow minimum corresponding to a geometry in which the two benzyl moieties are orthogonal was based on the observation that their quenching by O2 does not alter the trans/cis photostationary ratio. Our results with alpha-methylstilbene confirm the hypothesis that in the case of stilbene spin exchange quenching by O2 at the twisted geometry favors the cis isomer but occurs in competition with excitation transfer from transoid triplets that leads to the trans isomer and to singlet oxygen. The opposite effects of the two oxygen quenching paths on stilbene isomer composition cancel accidentally leading to an overall insensitivity of benzophenone-sensitized photostationary states to the presence of oxygen. Quenching rate constants derived on the basis of this cancellation are close to diffusion-controlled and predict singlet O2 quantum yields of 0.08 and 0.13 in the presence of air and under an O2 atmosphere, in good agreement with experimental measurements.
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Affiliation(s)
- Jack Saltiel
- Department of Chemistry and Biochemistry, The Florida State University, Tallahassee, FL 32306-4390, USA.
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17
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Catalán J, Saltiel J. On the Origin of Nonvertical Triplet Excitation Transfer: The Relative Role of Double-Bond and Phenyl-Vinyl Torsions in the Stilbenes. J Phys Chem A 2001. [DOI: 10.1021/jp010848p] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Javier Catalán
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid-España, Spain, and Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390
| | - Jack Saltiel
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid-España, Spain, and Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390
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18
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Saltiel J, Dmitrenko O, Reischl W, Bach RD. The Triplet Potential Energy Surface of s-trans-2,4-Hexadiene. A Comparison of Theory and Experiment. J Phys Chem A 2001. [DOI: 10.1021/jp003904f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jack Saltiel
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, and Department of Organic Chemistry, University of Vienna, A-1090, Vienna, Austria
| | - Olga Dmitrenko
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, and Department of Organic Chemistry, University of Vienna, A-1090, Vienna, Austria
| | - Wolfgang Reischl
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, and Department of Organic Chemistry, University of Vienna, A-1090, Vienna, Austria
| | - Robert D. Bach
- Department of Chemistry, Florida State University, Tallahassee, Florida 32306-4390, Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, and Department of Organic Chemistry, University of Vienna, A-1090, Vienna, Austria
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19
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Hager DC, Bentrude WG. Triplet-sensitized photorearrangements of six-membered-ring 2-phenylallyl phosphites. Reaction efficiency and stereochemistry at phosphorus. J Org Chem 2000; 65:2786-91. [PMID: 10808456 DOI: 10.1021/jo9918302] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D C Hager
- Department of Chemistry, University of Utah, Salt Lake City 84112, USA
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20
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Saltiel J, Crowder JM, Wang S. Mapping the Potential Energy Surfaces of the 1,6-Diphenyl-1,3,5-hexatriene Ground and Triplet States. J Am Chem Soc 1999. [DOI: 10.1021/ja982551j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jack Saltiel
- Contribution from the Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
| | - Janell M. Crowder
- Contribution from the Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
| | - Shujun Wang
- Contribution from the Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
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21
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Noda M, Matsushima K, Seki K, Yagi M. Effects of protonation on the lowest triplet state of trans-4,4′-dipyridylethylene. A time-resolved electron paramagnetic resonance study. Chem Phys Lett 1998. [DOI: 10.1016/s0009-2614(98)01083-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Wang H, Padias AB, Hall HK. Photoinduced Copolymerization and Cycloaddition of 2,3-Dimethyl-1,3-butadiene and Acrylonitrile. Macromolecules 1998. [DOI: 10.1021/ma980017q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hua Wang
- C.S. Marvel Laboratories, Chemistry Department, The University of Arizona, Tucson, Arizona 85721
| | - Anne Buyle Padias
- C.S. Marvel Laboratories, Chemistry Department, The University of Arizona, Tucson, Arizona 85721
| | - H. K. Hall
- C.S. Marvel Laboratories, Chemistry Department, The University of Arizona, Tucson, Arizona 85721
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23
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Saltiel J, Wang S, Ko DH, Gormin DA. Cis−Trans Photoisomerization of the 1,6-Diphenyl-1,3,5-hexatrienes in the Triplet State. The Quantum Chain Mechanism and the Structure of the Triplet State. J Phys Chem A 1998. [DOI: 10.1021/jp972941c] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jack Saltiel
- Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
| | - Shujun Wang
- Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
| | - Dong-Hoon Ko
- Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
| | - David A. Gormin
- Department of Chemistry, The Florida State University, Tallahassee, Florida 32306-4390
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24
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Bearpark MJ, Bernardi F, Olivucci M, Robb MA. Benchmarking the Molecular Mechanics−Valence Bond Method: Photophysics of Styrene and Indene. J Phys Chem A 1997. [DOI: 10.1021/jp971733h] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael J. Bearpark
- Dipartimento di Chimica 'G. Ciamician' dell' Universitá di Bologna, Via Selmi 2, 40126 Bologna, Italy, and Department of Chemistry, King's College London, Strand, London WC2R 2LS, U.K
| | - Fernando Bernardi
- Dipartimento di Chimica 'G. Ciamician' dell' Universitá di Bologna, Via Selmi 2, 40126 Bologna, Italy, and Department of Chemistry, King's College London, Strand, London WC2R 2LS, U.K
| | - Massimo Olivucci
- Dipartimento di Chimica 'G. Ciamician' dell' Universitá di Bologna, Via Selmi 2, 40126 Bologna, Italy, and Department of Chemistry, King's College London, Strand, London WC2R 2LS, U.K
| | - Michael A. Robb
- Dipartimento di Chimica 'G. Ciamician' dell' Universitá di Bologna, Via Selmi 2, 40126 Bologna, Italy, and Department of Chemistry, King's College London, Strand, London WC2R 2LS, U.K
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25
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Kakuho S, Seki K, Yagi M. Time-resolved electron paramagnetic resonance study of the lowest excited triplet states of trans-cinnamic acid and trans-cinnamate anion. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00900-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Huang Y, Bentrude WG. Structure-reactivity studies of the triplet-sensitized photorearrangements of allyl phosphites. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)01671-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Hubig SM, Bockman TM, Kochi JK. Identification of Photoexcited Singlet Quinones and Their Ultrafast Electron-Transfer vs Intersystem-Crossing Rates. J Am Chem Soc 1997. [DOI: 10.1021/ja963907z] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephan M. Hubig
- Contribution from the Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - T. Michael Bockman
- Contribution from the Department of Chemistry, University of Houston, Houston, Texas 77204-5641
| | - Jay K. Kochi
- Contribution from the Department of Chemistry, University of Houston, Houston, Texas 77204-5641
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Bentrude WG, Dockery KP, Ganapathy S, Lee SG, Tabet M, Wu YW, Cambron RT, Harris JM. Triplet-Sensitized Photorearrangements of 2-Phenylallyl Phosphites. J Am Chem Soc 1996. [DOI: 10.1021/ja960428r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wesley G. Bentrude
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Kevin P. Dockery
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Srinivasan Ganapathy
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Sueg-Geun Lee
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Michael Tabet
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Yuh-Wern Wu
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - R. Thomas Cambron
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
| | - Joel M. Harris
- Contribution from the Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
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