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Atar M, Öngel B, Riedasch H, Lippold T, Neudörfl J, Sampedro D, Griesbeck AG. Intra‐ and Intermolecular Fluorescence Quenching of Alkylthio‐Substituted Phthalimides by Photoinduced Electron Transfer: Distance, Position and Conformational Dependence. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Murat Atar
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
| | - Banu Öngel
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
| | - Henrik Riedasch
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
| | - Tim Lippold
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
| | - Jörg Neudörfl
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
| | - Diego Sampedro
- Departamento de QuímicaUniversidad de La Rioja Madre de Dios 53 E-26006 Logroño Spain
| | - Axel G. Griesbeck
- Department of ChemistryUniversity of Cologne Greinstr. 4 D-50939 Köln Germany
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2
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Codorniu-Hernández E, Hall KW, Boese AD, Ziemianowicz D, Carpendale S, Kusalik PG. Mechanism of O(3P) Formation from a Hydroxyl Radical Pair in Aqueous Solution. J Chem Theory Comput 2015; 11:4740-8. [DOI: 10.1021/acs.jctc.5b00783] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
| | | | - A. Daniel Boese
- Department
of Chemistry, Physical and Theoretical Chemistry, University of Graz, Heinrichstraße 28/IV, 8010 Graz, Austria
- Department
of Chemistry, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany
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3
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Zhang S, Wang X, Sui Y, Wang X. Odd-electron-bonded sulfur radical cations: X-ray structural evidence of a sulfur-sulfur three-electron σ-bond. J Am Chem Soc 2014; 136:14666-9. [PMID: 25299728 DOI: 10.1021/ja507918c] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The one-electron oxidations of 1,8-chalcogen naphthalenes Nap(SPh)2 (1) and Nap(SPh)(SePh) (2) lead to the formation of persistent radical cations 1(•+) and 2(•+) in solution. EPR spectra, UV-vis absorptions, and DFT calculations show a three-electron σ-bond in both cations. The former cation remains stable in the solid state, while the latter dimerizes upon crystallization and returns to being radical cations upon dissolution. This work provides conclusive structural evidence of a sulfur-sulfur three-electron σ-bond (in 1(•+)) and a rare example of a persistent heteroatomic three-electron σ-bond (in 2(•+)).
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Affiliation(s)
- Senwang Zhang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, and ‡Centre of Modern Analysis, Nanjing University , Nanjing 210093, China
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4
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Feldman VI. Structure and Reactions of Aliphatic Bridged Bifunctional Radical Ions: Exploring Fine-Tuning in Radiation Chemistry. Isr J Chem 2014. [DOI: 10.1002/ijch.201300122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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5
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Bonesi SM, Manet I, Freccero M, Fagnoni M, Albini A. Photosensitized oxidation of sulfides: discriminating between the singlet-oxygen mechanism and electron transfer involving superoxide anion or molecular oxygen. Chemistry 2007; 12:4844-57. [PMID: 16598801 DOI: 10.1002/chem.200501144] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The oxidation of diethyl and diphenyl sulfide photosensitized by dicyanoanthracene (DCA), N-methylquinolinium tetrafluoroborate (NMQ(+)), and triphenylpyrylium tetrafluoroborate (TPP(+)) has been explored by steady-state and laser flash photolysis studies in acetonitrile, methanol, and 1,2-dichloroethane. In the Et(2)S/DCA system sulfide-enhanced intersystem crossing leads to generation of (1)O(2), which eventually gives the sulfoxide via a persulfoxide; this mechanism plays no role with Ph(2)S, though enhanced formation of (3)DCA has been demonstrated. In all other cases an electron-transfer (ET) mechanism is involved. Electron-transfer sulfoxidation occurs with efficiency essentially independent of the sulfide structure, is subject to quenching by benzoquinone, and does not lead to Ph(2)SO cooxidation. Formation of the radical cations R(2)S(*+) has been assessed by flash photolysis (medium-dependent yield, dichloroethane>>CH(3)CN>CH(3)OH) and confirmed by quenching with 1,4-dimethoxybenzene. Electron-transfer oxidations occur both when the superoxide anion is generated by the reduced sensitizer (DCA(*-), NMQ(*)) and when this is not the case (TPP(*)). Although it is possible that different mechanisms operate with different ET sensitizers, a plausible unitary mechanism can be proposed. This considers that reaction between R(2)S(*+) and O(2)(*-) mainly involves back electron transfer, whereas sulfoxidation results primarily from the reaction of the sulfide radical cation with molecular oxygen. Calculations indeed show that the initially formed fleeting complex RS(2)(+)...O-O(*) adds to a sulfide molecule and gives strongly stabilized R(2)S-O(*)-(+)O-SR(2) via an accessible transition state. This intermediate gives the sulfoxide, probably via a radical cation chain path. This mechanism explains the larger scope of ET sulfoxidation with respect to the singlet-oxygen process.
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Affiliation(s)
- Sergio M Bonesi
- CHIDECAR-CONICET, Dep. Quim. Org., Fac. Cien. Ex. Nat. Universidad de Buenos Aires, Ciudad Universidaria, 1428 Buenos Aires, Argentina
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6
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Fourré I, Silvi B. What can we learn from two-center three-electron bonding with the topological analysis of ELF? HETEROATOM CHEMISTRY 2007. [DOI: 10.1002/hc.20325] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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7
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Görner H. Photoreactions of p-Quinones with Dimethyl Sulfide and Dimethyl Sulfoxide in Aqueous Acetonitrile†. Photochem Photobiol 2006; 82:71-7. [PMID: 16076243 DOI: 10.1562/2005-05-25-ra-540] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of dimethyl sulfide (DMS) and dimethyl sulfoxide (DMSO) on the photoreactions of 1,4-benzoquinone (BQ), 1,4-naphthoquinone (NQ), 9,10-anthraquinone (AQ) and several derivatives in acetonitrile/water were studied. The observed triplet state of the quinones is quenched and the rate constant is close to the diffusion-controlled limit for reactions of most quinones with DMS and lower with DMSO. Semiquinone radical anions (Q*-) produced by electron transfer from sulfur to the triplet quinone were detected. For both DMS and DMSO the yield of Q*- is similar, being generally low for BQ and NQ, substantial for AQ and largest for chloranil. The specific quencher concentrations and the effects of quinone structure and redox potentials on the time-resolved photochemical properties are discussed.
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Affiliation(s)
- Helmut Görner
- Max-Planck-Institut für Bioanorganische Chemie, D-45413 Mülheim an der Ruhr, Germany
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Braïda B, Hiberty PC. A Simplified Gaussian-2 Scheme for Determining Electron Affinities of Covalent Bonds. Application to the Disulfide Bond RS−SR‘ (R, R‘ = H, CH3, C2H5). J Phys Chem A 2003. [DOI: 10.1021/jp0341624] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Benoît Braïda
- Laboratoire de Chimie physique, Groupe de Chimie Théorique, Bat 490, Université de Paris-Sud, 91405 Orsay Cédex, France
| | - Philippe C. Hiberty
- Laboratoire de Chimie physique, Groupe de Chimie Théorique, Bat 490, Université de Paris-Sud, 91405 Orsay Cédex, France
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9
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Meurer EC, Gozzo FC, Augusti R, Eberlin MN. The kinetic method as a structural diagnostic tool: ionized alpha-diketones as loosely one-electron bonded diacylium ion dimers. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2003; 9:295-304. [PMID: 12939482 DOI: 10.1255/ejms.563] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The kinetic method is used to corroborate the description of ground state ionized alpha-diketones as loosely electron-bonded acylium ion dimers: R(1)-C=O(+)---e(-)---(+)O=C-R(2). The abundance ratio of both the acylium ion fragments R(1)CO(+) and R(2)CO(+) (summed to those of their respective secondary fragments) formed upon low energy (5 eV) collision-induced dissociation of several ionized alpha-diketones is found to correlate linearly with the ionization energies (IEs) of the corresponding R(1)CO(.) and R(2)CO(.) free radicals as predicted by density functional theory calculations at the B3LYP/6-311++G(d,p) level. However, when these abundances are taken from 70 eV electron ionization mass spectra, lower and sometimes inverted ratios (2,3-pentanedione and 2,3-hexanedione) are observed. Inverted ratios are also observed via charge-exchange mass spectrometry/mass spectrometry (MS/MS) experiments for ionized 2,3-pentanodione formed with relatively high internal energies. Ionized alpha-diketones are found to display an effective temperature of 1705 K, which indicates an intermediate loosely-bonded nature. B3LYP/6-311++G(d,p) optimized geometries and charge and spin densities also corroborate the description of ground state ionized alpha-diketones as loosely electron-bonded diacylium ion dimers.
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Affiliation(s)
- Eduardo C Meurer
- State University of Campinas - UNICAMP, Institute of Chemistry CP6154, 13083-970 Campinas, SP Brazil
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Braïda B, Thogersen L, Wu W, Hiberty PC. Stability, Metastability, and Unstability of Three-Electron-Bonded Radical Anions. A Model ab Initio Theoretical Study. J Am Chem Soc 2002; 124:11781-90. [PMID: 12296746 DOI: 10.1021/ja026707y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The stability of O therefore O, N therefore N, S therefore S, P therefore P, and Si therefore Si three-electron bonds in anionic radicals isoelectronic to dihalogen radical anions is studied by means of ab initio calculations on model systems. The difficulty of generating the dissociation energy profiles of such anions and their rearrangement to neutral species is solved by a practical method which consists of calculating the neutral and anionic energy profiles separately and shifting the curves with respect to each other to match the experimental energy gap between the asymptotes. Here the neutral and anionic reaction profiles are calculated at the CASPT2 and MP2 levels, respectively. The calculations predict that the O therefore O bond is likely to be observed in anions of the type [RO therefore OR](*-), where R is any alkyl substituent or carbon chain. The anion Si(2)H(6)(*-) is found to be a metastable species, with a fair barrier to electron detachment. The barrier is much smaller for N(2)H(4)(*-) and P(2)H(4)(*-), thus precluding experimental observation. However, these species can be stabilized by electron-attractor substituents, the effect of which can be quantitatively estimated by means of the parent anion's diagrams and some fast complementary calculations. An example is given with the [CF(3)HN therefore NHCF(3)](*-) anionic complex.
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Affiliation(s)
- Benoît Braïda
- Laboratoire de Chimie Physique, Groupe de Chimie Théorique, Bat 490, Université de Paris-Sud, 91405 ORSAY Cédex, France
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Braïda B, Hazebroucq S, Hiberty PC. Methyl substituent effects in [H(n)X...XH(n)](+) three-electron-bonded radical cations (X = F, O, N, Cl, S, P; n = 1 - 3). An ab initio theoretical study. J Am Chem Soc 2002; 124:2371-8. [PMID: 11878994 DOI: 10.1021/ja0165887] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effects of methyl substitution on the geometries and bonding energies of a systematic series of three-electron-bonded radical cations of the type [H(n)X...XH(n)](+), covering all possible symmetrical three-electron bonds that may take place between atoms of the second and third rows of the periodic table, have been investigated at the level of Møller-Plesset perturbation theory. Methyl substitution leads to significant weakening and lengthening of the X...X bond when X is a second-row atom. The effects increase with the number of substitutions and are more and more important in the series X = N, O, F. By contrast, methyl substitution leaves the bonding energies between third-row atoms practically unchanged but leads to a surprising bond shortening in the S...S and P...P cases. These seemingly contradictory effects are rationalized through a qualitative analysis based on an elementary molecular orbital description of three-electron bonding.
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Affiliation(s)
- Benoît Braïda
- Laboratoire de Chimie-Physique, Groupe de Chimie Théorique, Université de Paris-Sud, 91405 Orsay Cedex, France
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12
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Braı̈da B, Lauvergnat D, Hiberty PC. Symmetry-breaking and near-symmetry-breaking in three-electron-bonded radical cations. J Chem Phys 2001. [DOI: 10.1063/1.1373427] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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