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

• polyrotaxanes (4a and 4b), which consist of electron-accepting 9,9-dicyanomethylenefluorene 1 as an inclusion complex in persilylated β- or γ-cyclodextrin (TMS-β-CD, TMS-γ-CD) (1a, 1b) and methyltriphenylamine as an electron-donating molecule. They are statistically distributed into the conjugated chains of 9,9

• surfaces. Conclusion The synthesis and photophysical properties of two conjugated polyrotaxanes containing electron-accepting units encapsulated into TMS-β-CD or TMS-γ-CD cavities and electron-donating moieties, statistically distributed into the conjugated chains of 9,9-dioctylfluorene were investigated

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

• gram amounts of material. With this new methodology, we explored the effects on crystal packing morphology for the indeno[1,2-b]fluorene-6,12-diones by varying the substituents on the silylethynyl groups. Keywords: crystal packing; electron accepting; indenofluorenes; organic electronics; polycyclic

• emitting devices (OLED) [7]. For such devices to operate properly, these must include materials that conduct holes (electron donating) and conduct electrons (electron accepting) [8]. While there are many systems that display high hole mobilities, there are far fewer that exhibit high electron mobilities

• . This modest alteration imparts an inherent propensity of the IF scaffold to be electron accepting [10][11]. A simple explanation for the high electron affinity of the IF is that to make all five rings formally aromatic two electrons must be added to the system, effectively creating two cyclopentadiene

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• semiconductors. One of the possible ways of the preparation of low molecular mass semiconductors, showing higher than oligothiophene IP values, is to synthesize molecules in which a central electron accepting group separates two bi-, ter- or quaterthiophene units. Such compounds containing thiadiazole [10][11

• their extended conjugation and frequently have to be rendered soluble by introducing long alkyl- or alkoxy-type side substituents. This functionalisation opens up an additional route to modifying their redox, electronic and optical properties by using side substituents with different electron accepting

• the impaired conjugation of the triazole moiety with the bithiophene arms. Comparing the obtained results with those reported for similar donor–acceptor–donor compounds, we can see that both the number of donor groups and the chemical nature of the central electron accepting ring exert strong

Use of activated enol ethers in the synthesis of pyrazoles: reactions with hydrazine and a study of pyrazole tautomerism

• Denisa Tarabová,
• Stanislava Šoralová,
• Martin Breza,
• Marek Fronc,
• Wolfgang Holzer and
• Viktor Milata

Beilstein J. Org. Chem. 2014, 10, 752–760, doi:10.3762/bjoc.10.70

• ]. Electron-accepting groups can include ester, cyano, acetyl, nitro and trifluoroacetyl moieties. Thus, the simplest way to obtain activated enol ethers 3 is the condensation of active methylene components 2 such as malonic acid derivatives (esters, nitrile), (trifluoro)acetoacetic acid derivatives (esters

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

• control over the inter-fullerene separation. The fullerene triads exhibit good solubility in common organic solvents, have linear geometries and are diastereomerically pure. Cyclic voltammetric measurements demonstrate the excellent electron accepting capacity of all triads, with up to 6 electrons taken

• 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 and spectroscopic properties of 4-amino-1,8-naphthalimide derivatives involving the carboxylic group: a new molecular probe for ZnO nanoparticles with unusual fluorescence features

• Laura Bekere,
• David Gachet,
• Vladimir Lokshin,
• Wladimir Marine and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2013, 9, 1311–1318, doi:10.3762/bjoc.9.147

• electron-donating properties and weaker electron-accepting properties than ZnO [18]. Grafting to the surface of ZnO nanoparticles In order to investigate the behavior of acid 4 as a fluorescent molecular probe, preliminary experiments on grafting to the surface of ZnO nanoparticles (NPs) were carried out

Bioactive selaginellins from Selaginella tamariscina (Beauv.) Spring

• Chao Yang,
• Yutian Shao,
• Kang Li and
• Wujiong Xia

Beilstein J. Org. Chem. 2012, 8, 1884–1889, doi:10.3762/bjoc.8.217

• with its reduced form selaginellin (3). This may be correlated with the electron-accepting and delocalization effects of the formyl group, which favor the ionization of ArOH to the phenoxide anion ArO−, benefitting from both H-transfer and stabilization of the important mediator ArO−. The above two

Formation of carbohydrate-functionalised polystyrene and glass slides and their analysis by MALDI-TOF MS

• Martin J. Weissenborn,
• Johannes W. Wehner,
• Christopher J. Gray,
• Robert Šardzík,
• Claire E. Eyers,
• Thisbe K. Lindhorst and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2012, 8, 753–762, doi:10.3762/bjoc.8.86

• in the mass-to-charge ratio [14]. Previous attempts to get around this issue have involved coating polymer or glass surfaces with a thin membrane of conductive material, such as gold, carbon or indium-tin oxide [15][16][17], or the addition of electron-accepting additives, such as methyl viologen

• dichloride hydrate [14]. The addition of electron-accepting additives, however, did not completely suppress the mass shifts observed during MALDI-TOF MS on low-conductivity supports. Additionally, glass slides coated with conductive material are expensive and limited in their utility [14]. In order to

The Eschenmoser coupling reaction under continuous-flow conditions

• Sukhdeep Singh,
• J. Michael Köhler,
• Andreas Schober and
• G. Alexander Groß

Beilstein J. Org. Chem. 2011, 7, 1164–1172, doi:10.3762/bjoc.7.135

• in the separation of the desired product from phosphine sulfide byproducts. S-Alkylated ternary thioamides of type 7 usually undergo the episulfide formation and subsequent sulfide contraction smoothly (Scheme 2). This is due to the strong electron accepting nature of the thioiminium intermediate 8

• the investigated temperature of 220 °C. The influence of the different aromatic bromoketones on the reaction seems to be negligible. The electron accepting nature of the thio-substrate seems to have the dominating effect on the reaction performance. However, all investigated combinations of the

Palladium-catalyzed formation of oxazolidinones from biscarbamates: a mechanistic study

• Benan Kilbas and
• Metin Balci

Beilstein J. Org. Chem. 2011, 7, 246–253, doi:10.3762/bjoc.7.33

• (CHT–NOR) system 4a4b was an ideal starting point for construction of skeleton of 3. The CHT–NOR 4a4b equilibrium has been substantially delineated by means of both physical and chemical methods (Scheme 2) [9][10][11][12]. Electron accepting substituents, such as –CHO, –COOR, –CN etc. at C-7 tend to

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• the broad component. No reaction of 4-azidobenzonitrile 7 with InCl3, GaCl3 or AlCl3 was observed and no paramagnetic species were detected by EPR spectroscopy. It appears the electron-accepting property of the CN group inhibited the coupling process at some stage. It is also worth mentioning that, as

A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

• Marc Debeaux,
• Kai Brandhorst,
• Peter G. Jones,
• Henning Hopf,
• Jörg Grunenberg,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2009, 5, No. 31, doi:10.3762/bjoc.5.31

• derivatives have been shown to be efficient emitters for OLED applications [2]. In these devices, the benzanthrone moiety acts as an electron accepting group, whereas the diarylamine group functions as an electron donor. The reaction of 1 with various organometallic reagents was studied by Allen in the 1970s

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

• composed of P3HT and a variety of newly synthesized diarylmethanofullerene derivative 1a–k, 2 blends. Results and Discussion We prepared new diarylmethanofullerene derivatives which were studied as electron-accepting materials in the bulk-heterojunction device of organic thin-film photovoltaic cells

• (Figure 1). The new diarylmethanofullerenes have two aromatic rings on the cyclopropane, having electron-withdrawing and electron-donating groups. The electron-withdrawing groups were expected to increase the electron-accepting ability of fullerene, while the electron-donating groups would decrease the

Stereoselective synthesis of (2S,3S,4Z)-4-fluoro- 1,3-dihydroxy- 2-(octadecanoylamino)octadec- 4-ene, [(Z)-4-fluoroceramide], and its phase behavior at the air/water interface

• Gergana S. Nikolova and
• Günter Haufe

Beilstein J. Org. Chem. 2008, 4, No. 12, doi:10.3762/bjoc.4.12

• hydrogen bond donating and hydrogen bond accepting properties of the hydroxyl group. Consequently, placement of electron donating or electron accepting substituents close to this group will modify these properties and hence will change the physical, chemical as well the physiological properties of the