Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• . However, the yields of the products were not reported. Based on cyclic voltammetry and rotating ring-disk electrode measurements the authors suggested that Br− is electrochemically oxidized through Br to BrO− and that the latter is the oxidizing agent for cholesterol. The oxidation of cholesterol by

IR and electrochemical synthesis and characterization of thin films of PEDOT grown on platinum single crystal electrodes in [EMMIM]Tf₂N ionic liquid

• Andrea P. Sandoval,
• Marco F. Suárez-Herrera and
• Juan M. Feliu

Beilstein J. Org. Chem. 2015, 11, 348–357, doi:10.3762/bjoc.11.40

• , E-03080 Alicante, Spain 10.3762/bjoc.11.40 Abstract Thin films of PEDOT synthesized on platinum single electrodes in contact with the ionic liquid 1-ethyl-2,3-dimethylimidazolium triflimide ([EMMIM]Tf2N) were studied by cyclic voltammetry, chronoamperometry, infrared spectroscopy and atomic force

• electrochemical synthesis of PEDOT. The electrochemical properties of thin films of PEDOT are subsequently studied and compared with the behavior obtained in acetonitrile. Results and Discussion Cyclic voltammetry Figure 1 shows the cyclic voltammograms of EDOT in [EMMIM]Tf2N. The onset of the EDOT oxidation

• on platinum single crystal electrode substrates in [EMMIM]Tf2N. Cyclic voltammetry shows that the polymer grows faster in Pt(111) than in Pt(110) or Pt(100). On the other hand, the chronoamperometric experiments show that the activation energy for the oxidation and reduction processes is very low and

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

• Miriam Goll,
• Adrian Ruff,
• Erna Muks,
• Felix Goerigk,
• Beatrice Omiecienski,
• Ines Ruff,
• Rafael C. González-Cano,
• Juan T. Lopez Navarrete,
• M. Carmen Ruiz Delgado and
• Sabine Ludwigs

Beilstein J. Org. Chem. 2015, 11, 335–347, doi:10.3762/bjoc.11.39

• modification over the whole film. The integrity of the redox and optical behavior upon modification of the P(EDOT-N3-co-3T)-1:1 with sulfonic acid with regard to the parent copolymer was further proven by cyclic voltammetry and in situ spectroelectrochemistry. It was recently demonstrated that the azide group

Highly selective electrochemical fluorination of dithioacetal derivatives bearing electron-withdrawing substituents at the position α to the sulfur atom using poly(HF) salts

• Bin Yin,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2015, 11, 85–91, doi:10.3762/bjoc.11.12

• derivatives (dithioacetals) were prepared, and their oxidation potentials () were measured by cyclic voltammetry in an anhydrous acetonitrile (MeCN) solution containing n-Bu4NBF4 (0.1 M) using a platinum disk working electrode and a saturated calomel electrode (SCE) as the reference electrode. All compounds

A facile synthesis of functionalized 7,8-diaza[5]helicenes through an oxidative ring-closure of 1,1’-binaphthalene-2,2’-diamines (BINAMs)

• Youhei Takeda,
• Masato Okazaki,
• Yoshiaki Maruoka and
• Satoshi Minakata

Beilstein J. Org. Chem. 2015, 11, 9–15, doi:10.3762/bjoc.11.2

• electronegative diazene (–N=N–) moiety, diazahelicenes 2 are expected to possess stabilized LUMO energies. The LUMO energies, which were estimated from cyclic voltammetry (CV) experiments [ELUMO = –(4.8 + redE1/2) eV] using diluted CH2Cl2 solutions (10−4 M) of 2, range from –2.92 to –3.13 eV (for the full cyclic

Redox active dendronized polystyrenes equipped with peripheral triarylamines

• Toshiki Nokami,
• Naoki Musya,
• Tatsuya Morofuji,
• Keiji Takeda,
• Masahiro Takumi,
• Akihiro Shimizu and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2014, 10, 3097–3103, doi:10.3762/bjoc.10.326

• polystyrene equipped with peripheral triarylamines, which exhibited two sets of reversible redox peaks in the cyclic voltammetry curves. Keywords: carbocation; cross-coupling; dendrimer; dendronized polymer; redox; Introduction Assembling small functional molecules using dendrimers [1] and dendronized

• was studied by means of cyclic voltammetry (CV, Figure 5). Compound 9 showed two sets of reversible redox peaks (E1/2 = 0.80 and 1.04 V vs SCE), although it has been reported that di(p-methoxyphenyl)phenylamine shows a single redox peak in its CV curves [48]. Therefore, the two sets of redox peaks of

• electrode at room temperature. CH2Cl2 was used as a solvent and Bu4NBF4 (0.1 M) was used as a supporting electrolyte. The scan rate was 100 mV/s. The redox potentials (E1/2) of 5 and 10, and that of dendronized polystyrene 9 were measured by cyclic voltammetry (CV) using a GC working electrode (diameter

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• product distribution. Under aprotic conditions, the formation of 13 is favored, whereas in presence of HFIP (1,1,1,3,3,3-hexafluoroisopropanol) as a proton donor, product 14 is formed exclusively. On the basis of faradaic yields, cyclic voltammetry data and product distribution, the authors proposed the

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• oligofluorene arm length and substitution patterns of the central BODIPY core have been synthesised, leading to two families of compounds, T-B1–T-B4 and Y-B1–Y-B4, with T- and Y-shaped motifs, respectively. Thermal stability, cyclic voltammetry, absorption and photoluminescence spectroscopy of each member of

• these two families were studied in order to determine their suitability as emissive materials in photonic applications. Keywords: absorption spectroscopy; BODIPY; cyclic voltammetry; photoluminescence; star-shaped oligofluorene; Introduction The boron-dipyrromethene (BODIPY) or 4,4-difluoro-4-bora-3a

• were studied in dichloromethane solutions with the concentration of the analyte ca. 10−4 M, and the results are summarised in Table 2. The redox properties of the materials were investigated by cyclic voltammetry and the oxidation and reduction waves of Y-Bn (n = 1–4) and T-Bn (n = 1–4) series are

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• in a greater reduction potential in compound 10. This in turn contributes to the larger HOMO–LUMO gap determined by cyclic voltammetry for compound 10 with respect to compound 9. In addition to the DFT calculations, TDDFT was also carried out in order to investigate the vertical absorption profile of

• ] calculations were performed using wB97XD [63] functional with TZVP [64] basis set and SMD [65] solvent model implemented in Gaussian 09 [66]. Alkyl chains were shortened to methyl groups to lessen the computational cost. Chemical structures of DPP core 1 and BODIPY core 2. Cyclic voltammetry of 9 (black) and

Molecular ordering at electrified interfaces: Template and potential effects

• Thanh Hai Phan and
• Klaus Wandelt

Beilstein J. Org. Chem. 2014, 10, 2243–2254, doi:10.3762/bjoc.10.233

• Department, Quynhon University, 170 An Duong Vuong; Quynhon, Vietnam Institute of Experimental Physics, University of Wroclaw, MaxaBorna 9, 50-204, Wroclaw, Poland 10.3762/bjoc.10.233 Abstract A combination of cyclic voltammetry and in situ scanning tunneling microscopy was employed to examine the

• interactions, i.e., template-effects vs self-assembly, at different electrode potentials. Results Electrochemical characterization The electrochemical characterization of the Cu(111) surface in both pure 10 mM HCl and the viologen containing (10 mM HCl + 0.1 mM DBV2+) solution was done using cyclic voltammetry

• investigated by means of cyclic voltammetry and in situ scanning tunneling microscopy. Current waves in the cyclic voltammogram clearly indicate the potentials where reduction of the dications occurs first to the monocation radicals and then to the neutral molecules. At positive electrode potentials the

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• only be attributed to the excitonic contribution [39]. To further understand the electronic properties of the copolymers, the redox properties, i.e., the oxidation Eox and the reduction potentials Ered of the copolymers were investigated by cyclic voltammetry (CV) (Figure 9 and Table 3). CV experiments

Scalable synthesis of 5,11-diethynylated indeno[1,2-b]fluorene-6,12-diones and exploration of their solid state packing

• Bradley D. Rose,
• Peter J. Santa Maria,
• Aaron G. Fix,
• Chris L. Vonnegut,
• Lev N. Zakharov,
• Sean R. Parkin and
• Michael M. Haley

Beilstein J. Org. Chem. 2014, 10, 2122–2130, doi:10.3762/bjoc.10.219

• reductions with potentials of −0.78 to −0.84 V for the first reduction and −1.18 to −1.26 V for the second reduction. The small differences in the absorbance and cyclic voltammetry essentially fall within experimental error. Interestingly these compounds have a low energy S0→S1 transition at ca. 500–525 nm

Aryl substitution of pentacenes

• Andreas R. Waterloo,
• Anna-Chiara Sale,
• Dan Lehnherr,
• Frank Hampel and
• Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

• properties of the new pentacene chromophores have been analyzed by UV–vis spectroscopy (solution and thin films), thermoanalytical methods (DSC and TGA), cyclic voltammetry, as well as X-ray crystallography (for 8 derivatives). X-ray crystallography has been specifically used to study the influence of

• results are often observed between MPA and DSC. Cyclic voltammetry Electrochemical analysis by cyclic voltammetry (CV) was used to investigate the electronic properties of pentacene derivatives 3a–k in CH2Cl2 (ca. 1.5 mM) using tetrabutylammonium hexafluorophosphate as supporting electrolyte and ferrocene

• spectroscopy and cyclic voltammetry reveal that electronic communication between the pentacene core and the different substituents is limited, as a result of the orthogonal orientation of the pentacene backbone and the pendent aryl moieties. Thus, these results show that the nature of the substituent does not

Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

• Irina P. Romanova,
• Andrei V. Bogdanov,
• Inessa A. Izdelieva,
• Vasily A. Trukhanov,
• Gulnara R. Shaikhutdinova,
• Dmitry G. Yakhvarov,
• Shamil K. Latypov,
• Vladimir F. Mironov,
• Vladimir A. Dyakov,
• Ilya V. Golovnin,
• Dmitry Yu. Paraschuk and
• Oleg G. Sinyashin

Beilstein J. Org. Chem. 2014, 10, 1121–1128, doi:10.3762/bjoc.10.111

• working at 600.0 MHz in 1H and 150.9 MHz in 13C experiments. Chemical shifts are reported on the δ (ppm) scale and are relative to the residual 1H and 13C signal of CDCl3. The cyclic voltammetry (CV) curves were recorded using a three-electrode type electrochemical cell in o-DCB/MeCN (3:1 by volume

• . Optical absorption spectra of AIM 9, PCBM, and C60 in CH2Cl2 (2·10−5 mol·L−1, the cell thickness d = 2 mm). Inset shows the absorption spectra at d = 10 mm. Cyclic voltammetry curve of AIM 9. J–V characteristics of P3HT/AIMs and reference P3HT/PCBM devices for the P3HT/fullerene weight ratio 1:1

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• . These novel donor–acceptor dyads are electronically decoupled in the electronic ground state according to UV–vis spectroscopy and cyclic voltammetry. However, in the excited state the inherent donor luminescence is efficiently quenched. Previously performed femtosecond spectroscopic measurements account

• approximation. Keywords: absorption spectroscopy; cyclic voltammetry; chromophores; fluorescence; multicomponent reactions; photo-induced electron transfer; Introduction Chromophores, fluorophores, and electrophores, are functional organic materials [1] and constitute active components in molecular

• carbazole moieties as donors, and comprehensive physical organic studies of electronic and electrochemical properties investigated by steady state UV–vis and fluorescence spectroscopy as well as cyclic voltammetry. The obtained data are interpreted in the light of the Weller approximation to estimate the

Tailoring of organic dyes with oxidoreductive compounds to obtain photocyclic radical generator systems exhibiting photocatalytic behavior

• Christian Ley,
• Julien Christmann,
• Ahmad Ibrahim,
• Luciano H. Di Stefano and
• Xavier Allonas

Beilstein J. Org. Chem. 2014, 10, 936–947, doi:10.3762/bjoc.10.92

• by cyclic voltammetry using a potentiostat (Princeton Applied Research 263A) at a scan rate of 1 V/s in acetonitrile, with platinum as both working and auxiliary electrodes, and a saturated calomel reference electrode (KCl in methanol). Measurements were performed in acetonitrile using 0.1 M of

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

• Jacques Lalevée,
• Sofia Telitel,
• Pu Xiao,
• Marc Lepeltier,
• Frédéric Dumur,
• Fabrice Morlet-Savary,
• Didier Gigmes and
• Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

• -trapping, laser flash photolysis, steady state photolysis, cyclic voltammetry and luminescence experiments. Keywords: LEDs; photoinitiators; photopolymerization; photoredox catalysis; Introduction Photoredox catalysis is now well-known and largely used in organic synthesis, especially in the development

Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira–Glaser cyclization sequence

• Fabian Klukas,
• Alexander Grunwald,
• Franziska Menschel and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 672–679, doi:10.3762/bjoc.10.60

• quantum yield Φf. This finding correlates well with the planar ground state structure and an associated low Stokes shift. All studied representatives are potentially interesting singlet bluelight emitters. In addition, the electronic properties of the furans 2 have been studied by cyclic voltammetry

• . Computations account for significant distortions from coplanarity in the electronic ground state and the computed HOMO energies correlate with the first reversible oxidation potentials determined by cyclic voltammetry. Experimental Pseudo five-component synthesis of 2a [51] in a manner similar to [38]): A

• (22000). Fluorescence (CH2Cl2): λmax: 358 nm. Stokes shift Δ = 3800 cm−1. Quantum yield: Φf = 83% (Ref.: p-terphenyl (Φf = 93% in cyclohexane)). Cyclic voltammetry (CH2Cl2): E1/20/+1 = 1.25 V. Compounds 2d (solid and THF solution) and 2n (solid and THF solution) (from left to right) under daylight (top

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• physical properties similar to those of 1–4 and 6. Electrochemical characterisation of fullerene triads 1–6 Compounds 1–6 were studied by cyclic voltammetry (CV) as solutions in o-dichlorobenzene in order to investigate the sequence of electron additions and possible electronic interactions in these triads

• through the linker groups within the triads (Table 1 and Figure 2). Each triad molecule 1–6 exhibits a series of reduction processes in a potential range between −0.3 and −2.3 V (vs Fc+/Fc), some of which are overlapping or appear as shoulders to the main peaks. By comparison with the cyclic voltammetry

• fullerene triads where the nature of the fullerene cage and the length of the bridge between the cages can be controlled. Cyclic voltammetry measurements demonstrate the high electron accepting capacity of these molecules, which can accept up to six electrons reversibly, but indicate no interactions between

Synthesis, characterization and initial evaluation of 5-nitro-1-(trifluoromethyl)-3H-1λ³,2-benziodaoxol-3-one

• Nico Santschi,
• Roman C. Sarott,
• Elisabeth Otth,
• Reinhard Kissner and
• Antonio Togni

Beilstein J. Org. Chem. 2014, 10, 1–6, doi:10.3762/bjoc.10.1

• -(trifluoromethyl)-3H-1λ3,2-benziodaoxol-3-one (3), a hypervalent-iodine-based electrophilic trifluoromethylating reagent, is described. Whereas considerations based on cyclic voltammetry and X-ray structural properties would predict an inferior reactivity when compared to the non-nitrated derivative 2, 19F NMR

• kinetic studies showed that this new derivative is almost one order of magnitude more reactive. Furthermore, differential scanning calorimetry measurements indicated that, in addition, it is also safer to handle. Keywords: cyclic voltammetry; differential scanning calorimetry; electrophilic

• the initial hypothesis that nitration may lead to a more positive reduction potential, cyclic voltammetry (CV) measurements were carried out. These experiments were conducted under an atmosphere of nitrogen in anhydrous MeCN with Bu4NBF4 (0.1 M) as supporting electrolyte. A platinum working electrode

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• (1 mol %) and TBTA (1 mol %) under aerobic conditions [64]. Cyclic voltammetry measurements have supported the hypothesis of TBTA influencing the redox activity of copper(I), as the redox potential of the Cu(I)/Cu(II) pair was shown to rise by approximately 300 mV when the water-soluble derivative

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• readily measured by cyclic voltammetry, should be less positive than that of the photoexcited M. The solvent also has a significant impact on the oxidation and the subsequent reactions [43][44]. A polar solvent is generally favored for electron-transfer reactions involving amine radical cations, but

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

• Robert J. Perkins,
• Hai-Chao Xu,
• John M. Campbell and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

• form product 9. No product from sulfonamide trapping (8) was observed. However, when the reaction was run under more basic conditions (0.5 equivalents of lithium methoxide) cyclic voltammetry data indicated that the oxidative cyclizations were initiated by the oxidation of sulfonamide anion. This led

• afforded the five-membered ring product using either lithium methoxide or 2,6-lutidine as a base. Clearly, decarboxylation of the carboxylate anion was not a problem. In fact, cyclic voltammetry data suggest that the reaction originated from an oxidation of the ketene dithioacetal. The oxidation potential

• consistent with the formation of a radical cation followed by a cyclization that was too slow to compete with decomposition. The cyclic voltammetry data obtained were consistent with this observation. The +1.06 V versus Ag/AgCl oxidation potential measured for substrate 14c was the same as that measured for

Stability of SG1 nitroxide towards unprotected sugar and lithium salts: a preamble to cellulose modification by nitroxide-mediated graft polymerization

• Guillaume Moreira,
• Laurence Charles,
• Mohamed Major,
• Florence Vacandio,
• Yohann Guillaneuf,
• Catherine Lefay and
• Didier Gigmes

Beilstein J. Org. Chem. 2013, 9, 1589–1600, doi:10.3762/bjoc.9.181

• a solvent. The aim of the study was to measure the redox potentials of the SG1 and LiCl/solvent and to conclude if a redox reaction could happen between these species. The redox potentials of SG1 and LiCl (4.5 wt %) in DMF and MeOH were then determined by cyclic voltammetry with a platinum electrode

• Cl2 is a gas and thus difficult to quantify. We tried to prove the formation of Br2 by heating DMF/4.5 wt % LiBr solutions for 14 hours. A comparison with the same solution but with heating for only 30 min did not show any difference by cyclic voltammetry. In particular, the reduction wave of Br2 into

• of the solvent (DMF or DMA) with the lithium salt (LiCl or LiBr). The first hypothesis to explain the SG1 consumption in DMA/LiCl was based on the SG1 oxidation by Cl2 (or Br2 in the case of LiBr lithium salt). However, the study by cyclic voltammetry of the redox potential of SG1 and LiCl could not

Structures of the reaction products of the AZADO radical with TCNQF₄ or thiourea

• Hideto Suzuki,
• Yuta Kawahara,
• Hiroki Akutsu,
• Jun-ichi Yamada and
• Shin’ichi Nakatsuji

Beilstein J. Org. Chem. 2013, 9, 1487–1491, doi:10.3762/bjoc.9.169

• -configuration. The cyclic voltammetry (CV) data of TEMPO (1), AZADO (2), TCNQF4 (3) and the adduct 5 are summarized in Table 1. The lower first oxidation potential (E1OX) of AZADO than that of TEMPO suggests that the reaction between AZADO and TCNQF4 can take place slightly more easily than that between TEMPO

• TCNQF4 (3). The reaction of 2 with 4 to form 6. CV (cyclic voltammetry) data of TEMPO (1), AZADO (2), TCNQF4 (3) and adduct 5.a Supporting Information Supporting Information File 148: Experimental procedures and summary of crystal data of 5 and 6. Acknowledgements We are grateful to Mr. Toshimasa