New enzymatically polymerized copolymers from 4-tert-butylphenol and 4-ferrocenylphenol and their modification and inclusion complexes with β-cyclodextrin

• Adam Mondrzyk,
• Beate Mondrzik,
• Sabrina Gingter and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2118–2123, doi:10.3762/bjoc.8.238

• ). Furthermore, the behavior of polymer 7 clicked with β-CD was studied electrochemically (Figure 1, Table 1). The cyclic voltammetry (CV) data of copolymer 7 shows an anodic peak potential at 0.97 V, which shifts to 1.09 V with each oxidation/reduction cycle due to formation of a polymer layer on the electrode

• ). The temperature was measured by infrared detection with a continuous-feedback temperature control and maintained at a constant value by power modulation. Reactions were performed in closed vessels under controlled pressure. Cyclic voltammetry (CV) measurements were performed with a computer-controlled

• subsequent click chemistry with N3-β-CD. The covalently bound cyclodextrin moiety and the covalently bound Fc or tert-butyl group form host/guest complexes as proven by DLS measurement. The cyclic voltammetry data shows that the central iron atom of the Fc moiety is present in the copolymer and can be

Efficient electroorganic synthesis of 2,3,6,7,10,11-hexahydroxytriphenylene derivatives

• Carolin Regenbrecht and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2012, 8, 1721–1724, doi:10.3762/bjoc.8.196

• . The shift of potentials is supported by cyclic voltammetry studies. Keywords: catechol; electrochemical oxidation; hexahydroxytriphenylene; ketals; propylene carbonate; Introduction The unique spectroscopic and geometric features of triphenylenes give rise to a variety of applications for this very

• density allows a scale-up of this electroorganic synthesis. Cyclic voltammetry Cyclic voltammetry studies show that triphenylene ketal 2a gets more easily oxidized at lower potentials than subunit 1a (Figure 1). The first reversible process at Eox = 1.22 V corresponds to the oxidation of 2a to a radical

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• electrochemical properties of 1–3 were evaluated by cyclic voltammetry (CV) under the same experimental conditions reported previously [13]. The CV curves of diarylethenes 1–3 are shown in Figure 7. The onset potentials (Eonset) of oxidation and reduction for 1o were initiated at +1.79 and −0.89 V, and those of

• 1–3 at room temperature: (A) in hexane solution (2.0 × 10−5 mol L−1); (B) in PMMA films (10%, w/w). Emission intensity changes of diarylethene 1 upon irradiation with UV light at room temperature: (A) in hexane (excited at 307 nm), (B) in a PMMA film (excited at 324 nm). Cyclic voltammetry of

Hybrid super electron donors – preparation and reactivity

• Jean Garnier,
• Douglas W. Thomson,
• Shengze Zhou,
• Phillip I. Jolly,
• Leonard E. A. Berlouis and
• John A. Murphy

Beilstein J. Org. Chem. 2012, 8, 994–1002, doi:10.3762/bjoc.8.112

• compound 3 [16][27]. Cyclic voltammetry (CV) studies showed that the more powerful donors, e.g., 2 [15][16][18] and 4 [19], lose their second electrons at almost the same potential as their first electron (Figure 2 includes the CV of 4, showing a single two-electron redox wave, while Figure 4a includes

• trimethylene tethers. As compounds 10 and 11 are derived from imidazolium precursors, we were keen to explore their reactivity. The redox properties of the donors were first measured by cyclic voltammetry. Either the electron donors or their oxidized salts could, in principle, be used as a starting point for

• (hexafluorophosphate) salt 22. Cyclic voltammetry, starting with its oxidised disalt 22 (Figure 3, blue trace) shows that its redox activity occurs as two separate steps at potentials intermediate between those for compounds 6 and 8. [E1½ (DMF) = −1.54 V, E2½ (DMF) = −1.42 V versus Fc/Fc+; this corresponds to E1½ (DMF

Thiophene-based donor–acceptor co-oligomers by copper-catalyzed 1,3-dipolar cycloaddition

• Stefanie Potratz,
• Amaresh Mishra and
• Peter Bäuerle

Beilstein J. Org. Chem. 2012, 8, 683–692, doi:10.3762/bjoc.8.76

• -triazole co-oligomers were investigated by UV–vis spectroscopy and cyclic voltammetry. Several co-oligomers were electropolymerized to the corresponding conjugated polymers. Keywords: acetylene; azide; click chemistry; thiophene; triazole; Introduction Oligo- and polythiophenes are among the most

• properties, cyclic voltammetry of 5, 6, and 10–14 revealed redox transitions of the individual thiophene moieties (Table 3). Thus, cyclic voltammograms (CV) of 5 and 10 (5 × 10−3 M in dichloromethane/tetrabutylammonium hexafluorophosphate (TBAPF6, 0.1 M, 100 mV s−1) showed characteristic oxidation waves of

• respect to 9,10-diphenylanthracene (DPA, Φ = 0.9 in dichloromethane) [43]. Cyclic voltammetry experiments were performed with a computer-controlled EG&G PAR 273 potentiostat in a three-electrode single-compartment cell (2 mL). The platinum working electrode consisted of a platinum wire sealed in a soft

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• tetranuclear rectangular geometry with the dimensions of 5.53 Å × 12.39 Å. Furthermore, the photo- and electrochemical properties of these newly synthesized assemblies have been studied by using UV–vis absorption and cyclic voltammetry analysis. Keywords: cages; macrocycles; ruthenium(II); self-assembly; self

• -crystal X-ray diffraction analysis, which reveals a tetranuclear geometry with the dimensions of 5.53 Å × 12.39 Å. In addition to their synthesis and characterization, the UV–vis absorption and cyclic voltammetry studies are reported. Results and Discussion Synthesis and characterization of the

• novel, nanoscopic and functional metallamacrocycles and also to the study of their functional properties [15]. The photo- and electrochemical properties of our newly synthesized macrocycles (2a and 2b) are studied by UV–vis absorption and cyclic voltammetry investigations and the obtained results are

A ferrocene redox-active triazolium macrocycle that binds and senses chloride

• Nicholas G. White and
• Paul D. Beer

Beilstein J. Org. Chem. 2012, 8, 246–252, doi:10.3762/bjoc.8.25

• , 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.5, 3.0, 4.0, 5.0, 7.0 and 10 equivalents. Stability constants were obtained by analysis of the resulting data with the WinEQNMR2 [13] computer program, following the triazolium C–H protons in all cases. Electrochemistry protocols Cyclic voltammetry

• larger halide, iodide, is only weakly bound. The addition of small amounts (<1 equiv) of dihydrogen phosphate caused precipitation and, hence, no association constant could be calculated. Electrochemical Investigations The ability of 5·2PF6 to sense anions electrochemically was investigated by cyclic

• voltammetry in 0.1 M TBA·PF6 in CH3CN. The macrocycle displays a quasi-reversible oxidation of the ferrocene/ferrocenium couple, which is shifted to a more positive potential by 0.38 V relative to ferrocene by virtue of the positively charged triazolium groups of the receptor. Addition of one equiv of TBA·Cl

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• cationic complex was deposited as a monolayer onto an alkylsulfonate coated gold surface and elicited both a redox response, as determined by cyclic voltammetry, and a photochemical response to visible light [83][84]. The optical response was studied further [85], and a transient band was observed at 545

Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

• Antonio Avellaneda,
• Courtney A. Hollis,
• Xin He and
• Christopher J. Sumby

Beilstein J. Org. Chem. 2012, 8, 71–80, doi:10.3762/bjoc.8.7

• − anions in the solid-state [21]. Cyclic voltammetry experiments show that the most electron deficient hexaaryl[3]radialene synthesised thus far is hexakis(4-cyanophenyl)[3]radialene [17]. The focus of our current work is the synthesis of new hexaaryl- and hexa-heteroaryl[3]radialenes which are more

• . Cyclic voltammetry Cyclic voltammetry measurements were performed on a PAR Model 263A potentiostat under nitrogen. Measurements were recorded on 1 mM solutions in dichloromethane/0.1 M [(n-C4H9)4]NPF6] solution using a platinum working electrode, platinum wire auxiliary and pseudo-reference electrodes

• . Ferrocene was added as an internal standard on completion of each experiment and tabulated potentials are given vs the saturated calomel electrode [E0(Fc/Fc+) = 460 mV vs SCE (dichloromethane)]. Cyclic voltammetry was performed with a sweep rate of 100 mVs−1. X-ray crystallography Crystals were mounted

Sexithiophenes as efficient luminescence quenchers of quantum dots

• Christopher R. Mason,
• Yang Li,
• Paul O’Brien,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2011, 7, 1722–1731, doi:10.3762/bjoc.7.202

• Sexithiophenes 1a and 1b, in which a 4-(dimethylamino)phenyl unit is incorporated as an end-capping group, were synthesised and characterised by cyclic voltammetry, absorption spectroscopy and UV–vis spectroelectrochemistry. Additionally, their ability to function as effective luminescence quenchers for quantum

• trap states for nonradiative emission. Conclusion Two novel sexithiophene families, 1a,b and 2a,b, were synthesised and investigated as luminescence quenchers of quantum dots. Their properties were investigated by cyclic voltammetry, UV–vis absorption and spectroelectrochemistry. The addition of the

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• rearrangement of 19 to give 20 is estimated to proceed in 25–55% yield. Cyclic voltammetry (in dichloromethane, vs Ag/AgCl) showed two sequential, reversible oxidation steps for compound 20 at E1/2 = +0.72 and +1.09 V. To demonstrate the reactivity of the 1,4-shift products and to assess the degree of steric

• nm in 28). The spectrum of 28 also shows a broad feature at around 900 nm, corresponding to the π–π * transition of the highly delocalised nickel dithiolene unit. The electrochemistry of 3, 25, 27 and 28 was investigated by cyclic voltammetry. Solutions of the compounds (0.1 mM) were prepared in

• reflectance ATR instrument (4000–400 cm−1, resolution 4 cm−1). Elemental analysis was performed by the University of Manchester micro-analytical laboratory. Melting points were recorded on a Gallenkamp melting point apparatus and are uncorrected. Cyclic voltammetry was performed with a CH instruments

Structure and reactivity in neutral organic electron donors derived from 4-dimethylaminopyridine

• Jean Garnier,
• Alan R. Kennedy,
• Leonard E. A. Berlouis,
• Andrew T. Turner and
• John A. Murphy

Beilstein J. Org. Chem. 2010, 6, No. 73, doi:10.3762/bjoc.6.73

• the corresponding hexafluorophosphate salts 16′ and 18′ was then carried out prior to cyclic voltammetry. (The iodide anions were exchanged since iodide ions would be electrochemically active, albeit at more positive potentials than feature in our studies.) Cyclic voltammetry studies were carried out

• of the electron pair on the 4-substituent into the pyridine ring. Accordingly, the disalts 21 and 22 were prepared from these 4-substituted pyridines [43][45] and converted into their hexafluorophosphates 21′ and 22′, and then examined by cyclic voltammetry. Each showed a reversible two-electron

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

• Adam W. Franz,
• Svetlana Stoycheva,
• Michael Himmelhaus and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2010, 6, No. 72, doi:10.3762/bjoc.6.72

• presence of a gold-coated silicon wafer. Monolayer formation is confirmed by ellipsometry and the results compared to those obtained by force field and DFT calculations. Keywords: cyclic voltammetry; ellipsometry; phenothiazines; SAM; thiols; Introduction Functional organic π-systems [1] are of great

• “alligator-clips” and their electronic properties as studied by cyclic voltammetry (CV), spectroscopic and spectrometric methods. Furthermore, their chemisorption and SAM formation on Au{111} were studied by ellipsometry. Results and Discussion Synthesis The facile bromine–lithium exchange of bromo

• . Electronic properties The electronic properties of the (oligo)phenothiazinyl thioacetates 2 and 4 were investigated by absorption and emission spectra, and cyclic voltammetry (Table 1). Optical spectroscopy (UV–vis and fluorescence spectra) revealed that only the triad 2d and the tetrad 2e displayed

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• almost up to boiling point of water. Heating above 90 °C, results in destabilization of the complex and causes the polymer to precipitate. Furthermore, the reversibile redox behavior of complexed polyvinylferrocene 3 was evaluated by cyclic voltammetry. Oxidation of complexed polyvinylferrocene 3 to the

• /ionization-time-of-flight mass spectrometry (MALDITOF-MS) was performed on a Bruker Ultraflex TOF mass spectrometer. Cyclic voltammetry measurements were performed on a simplot instrument with a resolution of <100 pA. Dynamic light scattering (DLS) experiments were carried out with a Malvern HPPS-ET at 25 °C

• cyclic voltammetry for the complexed PVFc/PVFc+-system 3/6: 1.0 × 10−3 M substance in Na2SO4 | Ag/AgCl. Redox behaviour of PVFc 3: (a) the complexed PVFc 3 mixed with aqueous hydrogen peroxide solution was heated to 50 °C. The orange 3 oxidized to green PVFc+ 6 cation (b), which is reduced to the PVFc 4

Prediction of reduction potentials from calculated electron affinities for metal-salen compounds

• Sarah B. Bateni,
• Kellie R. England,
• Anthony T. Galatti,
• Handeep Kaur,
• Victor A. Mendiola,
• Alexander R. Mitchell,
• Michael H. Vu,
• Benjamin F. Gherman and
• James A. Miranda

Beilstein J. Org. Chem. 2009, 5, No. 82, doi:10.3762/bjoc.5.82

• Abstract The electron affinities (EAs) of a training set of 19 metal-salen compounds were calculated using density functional theory. Concurrently, the experimental reduction potentials for the training set were measured using cyclic voltammetry. The EAs and reduction potentials were found to be linearly

• (Epc) of the 19 metal-salens were then measured experimentally using cyclic voltammetry. Analogous methods were applied to obtain the Epc for a test set of 14 metal-salens employing a variety of new metals and substituents. Concurrently, density functional theory calculations enabled computation of EAs

• ligand were allowed to reflux for 1 h before the crude metal-salen was recrystallized in 95% ethanol. Each metal-salen was characterized by IR and High Resolution-Mass Spectrometry. Voltammetry: Cyclic Voltammetry was carried out at room temperature at 100 mV s−1 at a glassy carbon electrode in spectral

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• substitution and tail-length variation, has been presented elsewhere for a very similar cationic structure [20][25][26]. Electrochemical behaviour Cyclic voltammetry was used to determine the electrochemical behaviour of the compounds 1a, 1b and 1c, the voltammograms being recorded in CH3CN solutions

Synthesis of mesogenic phthalocyanine-C₆₀ donor–acceptor dyads designed for molecular heterojunction photovoltaic devices

• Yves Henri Geerts,
• Olivier Debever,
• Claire Amato and
• Sergey Sergeyev

Beilstein J. Org. Chem. 2009, 5, No. 49, doi:10.3762/bjoc.5.49

• group. Structural characterization of the molecules in solution was performed by NMR spectroscopy, UV–vis spectroscopy and cyclic voltammetry. Preliminary studies suggest formation of liquid crystalline (LC) mesophases for some of the prepared dyads. To the best of our knowledge, this is the first

• ) and B-band (between ca. 300 and ca. 450 nm) of phthalocyanine moiety, very strong high energy absorption of the cyclopropanated C60 derivative with the maximum at ca. 260 nm is observed (Figure 2). Cyclic voltammetry measurements of dyads 2a and 2d in CH2Cl2 produced essentially identical results

• was controlled by a Linkam Scientific Instruments GS350 hot stage. For DSC, a Perkin Elmer Diamond DSC calorimeter was used. Electrochemistry. Cyclic voltammetry experiments were performed with a computer controlled Autolab potentiostat. Measurements were carried out at room temperature in a three

New diarylmethanofullerene derivatives and their properties for organic thin- film solar cells

• Daisuke Sukeguchi,
• Surya Prakash Singh,
• Mamidi Ramesh Reddy,
• Hideyuki Yoshiyama,
• Rakesh A. Afre,
• Yasuhiko Hayashi,
• Hiroki Inukai,
• Tetsuo Soga,
• Shuichi Nakamura,
• Norio Shibata and
• Takeshi Toru

Beilstein J. Org. Chem. 2009, 5, No. 7, doi:10.3762/bjoc.5.7

• ) using a platinum electrode and tetrabutylammonium hexafluorophosphate as the supporting electrolyte in THF. Reduction potentials are listed in Table 1. The obtained cyclic voltammetry data were reversible. The first reduction potentials depend on the electron-donating nature of the substituents, in

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

• Abdelwareth A. O. Sarhan,
• Omar F. Mohammed and
• Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

• prepared as side products during the synthesis of the targeted compounds as bis(1,3-dithiafulvalene)ferrocenes 8, 10 and 11 in variable yields. The redox properties of the compounds have been investigated by cyclic voltammetry at ambient temperature using tetra-n-butylammonium perchlorate (TBAP) as the

• )ferrocenes 8, 10 and 11 exhibited two and three oxidation waves associated with two reduction waves. Keywords: cyclic voltammetry; charge-transfer (CT) complexes; diacylferrocenes; electrochemical properties; ferrocene-π-extended-dithiafulvalenes [bis(1,3-DTF)Fc’s]; organic conductors; Introduction

• 5c–e were studied by cyclic voltammetry at room temperature in dry CH2Cl2 solutions, using Pt working electrode, Pt gauze as a counter electrode and Ag/AgCl as a reference electrode and tetra-n-butylammonium perchlorate (TBAP) as the supporting electrolyte. The electrochemical data for the

Reduction of arenediazonium salts by tetrakis(dimethylamino)ethylene (TDAE): Efficient formation of products derived from aryl radicals

• Mohan Mahesh,
• John A. Murphy,
• Franck LeStrat and
• Hans Peter Wessel

Beilstein J. Org. Chem. 2009, 5, No. 1, doi:10.3762/bjoc.5.1

• arenediazonium cation) to the phenyl anion (+0.05 V vs SCE). Thus, it had long been noted that cyclic voltammetry of aryl halides, particularly iodides, can give rise to a single two-electron wave in the reductive part of the cycle. The first electron converts the aryl iodide to the corresponding aryl radical

• cyclic voltammetry and to determine the potential for conversion of aryl radicals to aryl anions. In the event, their study [60] showed two reductive peaks for benzenediazonium tetrafluoroborate (Ep 0.16 V and −0.64 V vs SCE). Through detailed analysis, Andrieux and Pinson showed that this second peak

Effect of transannular interaction on the redox- potentials in a series of bicyclic quinones

• Grigoriy Sereda,
• Jesse Van Heukelom,
• Miles Koppang,
• Sudha Ramreddy and
• Nicole Collins

Beilstein J. Org. Chem. 2006, 2, No. 26, doi:10.1186/1860-5397-2-26

• product of one-electron reduction of the quinone 5 was treated at the restricted open shell density functional level (ROB3LYP). The MO images were visualized with the Orb Draw 3.00.1 program [13]. The cyclic voltammetry data (first reduction peak potential Epr1, first oxidation peak potential Epox1, first

• compounds 1–5 vs. their calculated LUMO+1 energies. LUMO of Compound 1. LUMO+1 of Compound 1. LUMO of Compound 2. LUMO+1 of Compound 2. LUMO of Compound 4. LUMO+1 of Compound 4. LUMO of Compound 5. LUMO+1 of Compound 5. LUMO of the reduced species 5·−. CV for p-benzoquinone and quinone 3. Cyclic Voltammetry