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Search for "oxidation potential" in Full Text gives 114 result(s) in Beilstein Journal of Organic Chemistry.

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

  • Aude-Héloise Bonardi,
  • Frédéric Dumur,
  • Guillaume Noirbent,
  • Jacques Lalevée and
  • Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

Graphical Abstract
  • electronically excited state which significantly changes the distribution of electrons in the molecule. Thus, chemical properties such as reactivity, oxidation potential or reduction potential change drastically. With appropriate donors or acceptors, electron charge transfer is possible via this excited state
  • equation: where Eox is the oxidation potential of the electron donor, Ered the reduction potential of the electron acceptor, E* the excited state energy level and C the coulombic term for the initially formed ion pair (if there are ions in solution). For polar solvent, C is neglected. (TMS)3SiH is not
  • photopolymerization initiation as shown in [53] (see Part 3). For this purpose, the Ir complex was more interesting than the Ru one because of the longer excited state lifetime, lower oxidation potential leading to higher interaction rate constants with additives used for ring-opening photopolymerization (e.g
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Published 12 Dec 2018

Oxidative and reductive cyclization in stiff dithienylethenes

  • Michael Kleinwächter,
  • Ellen Teichmann,
  • Lutz Grubert,
  • Martin Herder and
  • Stefan Hecht

Beilstein J. Org. Chem. 2018, 14, 2812–2821, doi:10.3762/bjoc.14.259

Graphical Abstract
  • Table S1 (Supporting Information File 1). For most ring-open compounds investigated, the E-isomer displayed a higher or at least equal oxidation potential when compared to the Z-isomer. This difference for both open isomers is rather surprising in view of their very similar absorption maxima in first
  • line with the largely reduced HOMO–LUMO gap of the colored closed isomers implying an energetically higher and thus more accessible HOMO level. The first and second oxidation potential are shifted depending on the electron-donating or electron-withdrawing character of the attached substituents
  • oxidation potential, hollow circles to the second oxidation potential (if available). For detailed data, see Table S1, for all respective cyclovoltammograms, see Figure S10 to Figure S27 in Supporting Information File 1. Cyclic voltammograms of sDTE66-PhCN. The reduction of a) E-sDTE66-PhCN (black line) is
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Published 09 Nov 2018

Synthesis of aryl sulfides via radical–radical cross coupling of electron-rich arenes using visible light photoredox catalysis

  • Amrita Das,
  • Mitasree Maity,
  • Simon Malcherek,
  • Burkhard König and
  • Julia Rehbein

Beilstein J. Org. Chem. 2018, 14, 2520–2528, doi:10.3762/bjoc.14.228

Graphical Abstract
  • (dtbpy)]PF6 as the photocatalyst. The reaction was carried out under nitrogen under visible-light irradiation at 455 nm. The oxidation potential of this test arene is 1.02 V vs SCE, which allows oxidation by [Ir(dF(CF3)ppy)2(dtbpy)]PF6 having an estimated excited state oxidation potential of 1.21 V vs
  • addition of 1,2,4-trimethoxybenzene (oxidation potential 1.02 V vs SCE, Figure 3a). The values are similar to the estimated excited state oxidation potential of [Ir(dF(CF3)ppy)2(dtbpy)]PF6 ( +1.21 V vs SCE in acetonitrile). On the other hand, the luminescence was quenched negligible on addition of diphenyl
  • )]PF6 and also did not give a sulfenylated product under our photocatalytic conditions. This is rationalized by the oxidation potential of anisole of 1.76 V vs SCE, which is higher than the estimated excited state oxidation potential of the photocatalyst. To elucidate, if the 1,3,5-TMB radical cation
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Published 27 Sep 2018

Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

  • Hendrik V. Schröder and
  • Christoph A. Schalley

Beilstein J. Org. Chem. 2018, 14, 2163–2185, doi:10.3762/bjoc.14.190

Graphical Abstract
  • so-called mixed-valence dimer (12) ●+. A mixed-valence dimer can be identified by splitting of the first TTF oxidation potential into two distinguishable waves. This change in redox behavior can be followed by electrochemical methods such as cyclic voltammetry. Another indication for a mixed-valence
  • latter technique revealed an increase of oxidation potential for the first one-electron oxidation, but a second oxidation potential similar to that of the free axle. This indicates that the wheel already moves away from the TTF station upon the first oxidation to the TTF●+ radical cation. Another example
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Published 20 Aug 2018

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

  • Mohammad A. Alnajjar,
  • Jürgen Bartelmeß,
  • Robert Hein,
  • Pichandi Ashokkumar,
  • Mohamed Nilam,
  • Werner M. Nau,
  • Knut Rurack and
  • Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

Graphical Abstract
  • the 2,8-diethyl-1,3,7,9-tetramethyl-BODIPY core acceptor of 3 in acetonitrile [47], an oxidation potential of +0.0625 V for the aniline donor [48][49], and the vibrational zero electronic energy was determined as 2.46 eV from absorption and emission spectra. This gave ∆G values of −87.6 kJ mol−1 for 1
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Published 30 Jul 2018

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

  • Xiang Li,
  • Pinhong Chen and
  • Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

Graphical Abstract
  • first hypervalent iodine(III)-catalyzed reaction, in which the iodine(III) reagent was in situ generated by anodic oxidation under electrochemical conditions [36]. Critical to success of this process is that the oxidation potential of the catalysts should be much lower than those of the substrates and
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Published 18 Jul 2018

Polysubstituted ferrocenes as tunable redox mediators

  • Sven D. Waniek,
  • Jan Klett,
  • Christoph Förster and
  • Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

Graphical Abstract
  • essentially reversible behaviour for the ferrocene/ferrocenium oxidation process (Figure 1, Figure S1, Supporting Information File 1). The electrochemical potentials cover a wide range, E1/2 = 260–900 mV vs FcH/FcH+ (Figure 1, Table 1). The oxidation potential of the tetraester 4 is very high with E1/2 = 900
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Published 07 May 2018

Anodic oxidation of bisamides from diaminoalkanes by constant current electrolysis

  • Tatiana Golub and
  • James Y. Becker

Beilstein J. Org. Chem. 2018, 14, 861–868, doi:10.3762/bjoc.14.72

Graphical Abstract
  • studied by cyclic voltammetry and all of their redox potentials were found to be irreversible in acetonitrile. Their first oxidation potentials (in the range of 2.1–2.35 V vs Ag/AgCl) are summarized in Table 1. The first and second columns indicate that the longer the spacer the higher the oxidation
  • potential. Also it is not surprising that the derivative with EWG (IV) is more difficult to oxidize than that with EDG (III). All bisamides derivatives exhibit one irreversible cathodic wave (not shown, at −2.2 to −2.4 V). Constant current electrolysis (CCE) at a current density of 20 mA/cm2 was carried out
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Published 16 Apr 2018

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

  • Shunsuke Kuribayashi,
  • Tomoyuki Kurioka,
  • Shinsuke Inagi,
  • Ho-Jung Lu,
  • Biing-Jiun Uang and
  • Toshio Fuchigami

Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27

Graphical Abstract
  • these compounds have rather high oxidation potentials. DFT calculation of 1a indicated that the highest occupied molecular orbital (HOMO) is located at the sulfur atom (Figure 2). Although sulfur atoms are easily oxidized, the oxidation potential of 1a was found to be extremely high, that is due to the
  • . Regardless of the electrolytic conditions, the anodic fluorination proceeded to provide the desired fluorinated product 2a except for the electrolysis performed in dimethoxyethane (DME) as the solvent (Table 1, entry 3). The oxidation potential of 1a is rather high, while that of DME is relatively low [24
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Published 12 Feb 2018

Synthesis of fluoro-functionalized diaryl-λ3-iodonium salts and their cytotoxicity against human lymphoma U937 cells

  • Prajwalita Das,
  • Etsuko Tokunaga,
  • Hidehiko Akiyama,
  • Hiroki Doi,
  • Norimichi Saito and
  • Norio Shibata

Beilstein J. Org. Chem. 2018, 14, 364–372, doi:10.3762/bjoc.14.24

Graphical Abstract
  • biological evaluation, this is the first report to highlight the cytotoxicity of diaryliodonium salts against U937 cells. Since diaryliodonium salts are fundamentally oxidizing agents, there might be a stronger correlation between cytotoxicity and the oxidation potential of these salts. We will continue the
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Published 07 Feb 2018

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

  • Thanh-Tuân Bui,
  • Fabrice Goubard,
  • Malika Ibrahim-Ouali,
  • Didier Gigmes and
  • Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

Graphical Abstract
  • dihedral angle of T21–T23 contributed to spatially separate the HOMO from the LUMO orbitals. By electrochemistry, an appreciable reduction of the oxidation potential was detected (+0.87 V) for T21 which is substituted at the 1,8-positions of the donor whereas T20, T22 and T23 exhibited the same oxidation
  • - and T23-based devices, respectively. As anticipated, a lower color purity was obtained for T21-based devices resulting from its lower oxidation potential. Recently, a significant enhancement of blue OLED performances was obtained by replacing the triazine acceptor by a 2,4,6-triphenylpyrimidine unit
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Published 30 Jan 2018

Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

  • Anna Kuźnik,
  • Roman Mazurkiewicz and
  • Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

Graphical Abstract
  • under a nitrogen atmosphere in dichloromethane solution on a graphite anode and a cathode of stainless steel at a constant current of 20 mA (Scheme 12). Depending on the cycloalkene used, the target vinylphosphonium salt was obtained in a yield of 53–66% [19]. Since the oxidation potential of
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Published 15 Dec 2017

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

  • Satoru Mori and
  • Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

Graphical Abstract
  • electronegativity of fluorine and has been successfully isolated. In measurements of cyclic voltammetry, iron phthalocyanines with an alkoxy group show a lower first oxidation potential than unsubstituted iron phthalocyanine, but TFEO-FePc shows a more difficult oxidation process than unsubstituted iron
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Published 27 Oct 2017

Diastereoselective anodic hetero- and homo-coupling of menthol-, 8-methylmenthol- and 8-phenylmenthol-2-alkylmalonates

  • Matthias C. Letzel,
  • Hans J. Schäfer and
  • Roland Fröhlich

Beilstein J. Org. Chem. 2017, 13, 33–42, doi:10.3762/bjoc.13.5

Graphical Abstract
  • literature [25], where the oxidation potential for anisole and toluene was determined to be 1.15 V and 1.35 V (vs Ag/Ag+), respectively. In the Kolbe electrolysis a critical potential of 1.9 to 2.2 V (vs Ag/AgCl) has to be exceeded. At this potential the coverage of the electrode with carboxylate ions
  • increases sharply, the oxygen evolution is inhibited, solvent oxidation is retarded and the Kolbe electrolysis is promoted [26]. If in the carboxylate an additional electrophore with a lower oxidation potential than the critical potential is present it is oxidized instead of the carboxylate group. This is
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Published 05 Jan 2017

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

  • Dominik Urselmann,
  • Konstantin Deilhof,
  • Bernhard Mayer and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

Graphical Abstract
  • electronics [37][38][39][40]. In comparison to thiophene, phenothiazine, a tricyclic dibenzo-1,4-thiazine, possesses a significantly lower oxidation potential, similar to aniline. However, phenothiazine derivatives form stable deeply colored radical cations with perfect Nernstian reversibility [41][42][43][44
  • involved. Electronic spectra and oxidation potentials The electronic properties of the three thienyl-bridged oligophenothiazines 3 were experimentally investigated by absorption and emission spectroscopy and by cyclic voltammetry (Table 1). Cyclic voltammetry discloses the oxidation potential as an
  • electronic communication between both electrophore moieties. The first oxidation potential of 2,5-bis(diphenothiazinyl)thiophene 3b is cathodically shifted and appears at a peak potential of E1/2 = 620 mV, however, without displaying Nernstian behavior (Figure 2, center). Two further oxidation waves can be
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Published 20 Sep 2016

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

  • Forrest S. Etheridge,
  • Roshan J. Fernando,
  • Sandra Pejić,
  • Matthias Zeller and
  • Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

Graphical Abstract
  • addition of fluorine [13]. The second oxidation potential for all zinc(II) chelates, 0.77–0.79 V, showed little change except in two cases: Zn(L4)2 and Zn(L2)2 had second oxidation potentials of 0.84 V and 0.73 V, respectively. The differences between the first and second oxidation potential was 0.27 V for
  • Zn(WS3)2, while it was 0.18 V and 0.19 V for Zn(L1)2 and Zn(L2)2, respectively. For both Zn(L3)2 and Zn(L4)2 the difference between oxidation potentials was 0.23 V, a slight decrease from Zn(WS3)2 at 0.27 V. All of the fluorinated zinc(II) complexes exhibit a rise of the first oxidation potential as
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Published 29 Aug 2016

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

  • Adrian E. Ion,
  • Liliana Cristian,
  • Mariana Voicescu,
  • Masroor Bangesh,
  • Augustin M. Madalan,
  • Daniela Bala,
  • Constantin Mihailciuc and
  • Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

Graphical Abstract
  • , the more anodic peak was tentatively assigned to the formation of the cation radical of the azulene moiety. The DPV experiments confirmed that stabilization of the tropylium cation in the case of 4b, the oxidation potential being shifted anodically at 0.70 V as compared to 0.56 V for 4a (Figure 7
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Published 11 Aug 2016

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

  • Wei Li,
  • Munechika Otsuka,
  • Takehito Kato,
  • Yang Wang,
  • Takehiko Mori and
  • Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

Graphical Abstract
  • oxidation peaks in the measurement range (Figure 1b). 3,6-Cbz-EDOT exhibited the onset oxidation potential (Eox,onset) at 0.38 V (vs Ag/Ag+), whereas the Eox,onset of 2,7-Cbz-EDOT was slightly higher (0.50 V). This difference can also be explained by the different connectivity pattern between the two
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Published 07 Jul 2016

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

  • Minh Anh Truong and
  • Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

Graphical Abstract
  • showed one oxidation wave with an onset potential of 0.56 eV (vs Fc/Fc+, HOMO = −5.36 eV). The lower oxidation potential and higher HOMO energy level of syn-DNBDF 6 should reflect its longer π-conjugation length than syn-DBBDF 5. Based on their HOMO energy levels and HOMO−LUMO energy gaps, syn-DBBDF 5
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Published 26 Apr 2016

Study on the synthesis of the cyclopenta[f]indole core of raputindole A

  • Nils Marsch,
  • Mario Kock and
  • Thomas Lindel

Beilstein J. Org. Chem. 2016, 12, 334–342, doi:10.3762/bjoc.12.36

Graphical Abstract
  • PMB group, because the oxidation potential of DMB ethers is lower and the cleavage was expected to be more facile [45]. Indole synthesis from DMB-protected 13 and subsequent Boc protection afforded 16 (58%). Alkynylation and desilylation of 16 to 19 and coupling of 19 with ketone 6 proceeded smoothly
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Published 23 Feb 2016

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

  • Baiba Turovska,
  • Henning Lund,
  • Viesturs Lūsis,
  • Anna Lielpētere,
  • Edvards Liepiņš,
  • Sergejs Beljakovs,
  • Inguna Goba and
  • Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

Graphical Abstract
  • difference between the first oxidation potential of the donor and the first reduction potential of the acceptor; In CH2Cl2 the reduction potential of O2 is −1.18 V and E0 of 1 is +1.14 V. The reaction becomes thermodynamically favourable if the organic molecule is excited to a singlet state. The oxidation
  • potential of excited molecules is shifted to negative values (ΔE = ~2 V) compared to their ground state [21][22][23]. For example the oxidation potential of 9,10-dihydro-10-methylacridine is +0.80 V [23], which is shifted to −3.10 V in the singlet excited state [23]. The recorded UV–vis spectrum of 1
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Published 11 Nov 2015

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

  • Vasily M. Muzalevskiy,
  • Aleksei V. Shastin,
  • Alexandra D. Demidovich,
  • Namiq G. Shikhaliev,
  • Abel M. Magerramov,
  • Victor N. Khrustalev,
  • Rustem D. Rakhimov,
  • Sergey Z. Vatsadze and
  • Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

Graphical Abstract
  • intermediates in the synthesis of ferrocene analogs of tamoxifen and other medicinally relevant molecules. Electrochemical properties of halovinylferrocenes The ferrocene unit possesses several exciting electrochemical characteristics, such as fast electron-transfer rate, low oxidation potential, and stability
  • . The values of the respective oxidation potential depend mainly on the amount of the vinyl groups attached to the ferrocene core. There is also the effect of the halogen atom, though to a lesser extent compared to the effect of the amount of vinyl groups. For example, all dichloro and dibromo compounds
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Published 03 Nov 2015

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

  • Alexander L. Kanibolotsky,
  • Neil J. Findlay and
  • Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

Graphical Abstract
  • oxidation potential of TTF and that of the thiophene backbone of the monomer, the TTF-modified bithiophene compounds 5b–d were used as monomers for electropolymerisation to 6b–d [49]. The appearance of an additional, well-defined oxidation wave in the CV, as the first oxidation wave was split in both anodic
  • ]. Polymers with fused TTF units The electronic characterisation for monomer units 14a–c and 28a is shown in Table 1. Electropolymerisation of monomer compounds 14a, 14c and 28a [73] was attempted. Due to the high oxidation potential (see Table 1) of the thiophene unit in the fused system 14a (2.18 V vs Ag
  • polaron charge carrier route; 3) the oxidation potential of the polymer backbone is likely to be in the same region as the potential for TTF2+ formation, although the contribution to the current from the normally irreversible oxidation of the PT backbone would be small due to the high TTF content in the
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Published 28 Sep 2015

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

  • Masahiko Iyoda and
  • Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

Graphical Abstract
  • CH2Cl2 based on the high HOMO levels of TTF units. Another important feature in the CV data of 28–32 is broadening or splitting of the first oxidation wave, indicating intra- and/or intermolecular interactions between TTF units [68]. Interestingly, the first oxidation potential of 28 and 29 splited at
  • the slow scanning rate of 3 mV s−1 owing to the intermolecular mixed-valence interaction between the TTF•+ and TTF moieties under diffusion-controlled conditions. In the case of 31, the first oxidation potential (E1/2 = 0.14 V vs Fc/Fc+) is lower than that of 32 with alkyl groups (E1/2 = 0.20 V
  • ). Since the first oxidation potential of 31 in a dilute solution broadened but did not split (E1/2ox1 in CH2Cl2: 0.23 (3e) V), the potential of 31 at 0.14 V (Table 4) reflected the strong intermolecular interaction between the TTF•+ and TTF moieties in 31•+. By comparison with the known UV–vis/NIR spectra
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Published 10 Sep 2015

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

  • Awatef Ayadi,
  • Aziz El Alamy,
  • Olivier Alévêque,
  • Magali Allain,
  • Nabil Zouari,
  • Mohammed Bouachrine and
  • Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

Graphical Abstract
  • the second cycle a negligible change of the oxidation potential of the ligand which is very likely because of the large distance between the TTF and the fluoride coordinating unit (Figure S8 in Supporting Information File 1). In order to get further supports to the observed optical sensing and to get
  • ). This increase of the oxidation potential suggests that the rhenium fragment is acting as an electron acceptor by decreasing the electron density on the TTF unit. This behavior is in agreement with the electronic absorption experiments and confirms the strong electronic conjugation in ligand L2. The
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Published 07 Aug 2015
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