Separation and identification of indene–C₇₀ bisadduct isomers

• Bolong Zhang,
• Jegadesan Subbiah,
• David J. Jones and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

• separation; electron acceptor; fullerene bisadduct; organic solar cell; regioisomers; Introduction Organic solar cells (OSCs) are an emerging renewable energy technology that has achieved remarkable progress over the past two decades. Compared to traditional inorganic semiconductor solar cells, OSCs promise

• . Fullerenes and their derivatives are widely used in BHJ OSC devices as the electron acceptor material. They have several characteristics that make them favorable for this application including good electron transport [2], reversible reduction behavior [3], and easily functionalized structures [4]. Indene

• thin film nanostructure are key factors in determining the performance of these fullerene derivatives in BHJ solar cell devices. With the observations in this study, it can be argued that the success of IC70BA (and in extension, IC60BA) as the electron acceptor component in BHJ solar cells is

Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties

• Xiang Sun,
• Guoqiao Lai,
• Zhifang Li,
• Yuwen Ma,
• Xiao Yuan,
• Yongjia Shen and
• Chengyun Wang

Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255

• to explore the formation of the charge-transfer complexes. TTF derivates are representative electron donors, while TCNQ is a typical electron acceptor. When one equivalent of TCNQ was added to the solution of T1 in ethyl acetate, TCNQ radical anion species (TCNQ•−) and TTF radical cation species (TTF

Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case

• Karina Mroczyńska,
• Małgorzata Kaczorowska,
• Erkki Kolehmainen,
• Ireneusz Grubecki,
• Marek Pietrzak and
• Borys Ośmiałowski

Beilstein J. Org. Chem. 2015, 11, 2105–2116, doi:10.3762/bjoc.11.227

• ) carrying electron acceptor 8 (R = CF3) and 10. The salt 9 was not taken into account because, most probably, it forms two types of complexes as discussed earlier. For salts 2, 5 and 8 the following [1]:[benzoate] ratios were used: 1:0.5, 1:1 and 1:2, while for [1]:[10] 1:0.1, 1:0.5 and 1:1. The temperature

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

• ). Compound 22 is normally synthesised by transchalcogenation from the corresponding 1,3-dithiole-2-thione derivative. One method for the synthesis of 1,3-dithiole-2-thione with electron-acceptor substituents [61] is the reaction of readily accessible ethylene trithiocarbonate (23) [62] with electron

• PC71BM as the electron acceptor using ortho-diclorobenzene (o-DCB) and chloroform as solvents (Table 3). The devices prepared with o-DCB showed up to a two-fold increase in power conversion efficiency (PCE) compared to those obtained by spincoating the blend from chloroform, which is due to a more

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• where the electron can reduce an electron acceptor with a suitable redox potential to a radical anion (A–•) and/or the hole can oxidize an electron donor to the radical cation (D+•, Figure 1). Recombination, whereby the electron drops back down to the VB, occurs in competition with this in the bulk of

• radicals. A sacrificial electron acceptor is required to scavenge the electrons from the e−/h+ pair. This may be a solvent, excess of an electron-deficient substrate or an additive. The neutral radicals can then be exploited in addition, cyclization, coupling or reductive processes. The alternative process

Synthesis of racemic and chiral BEDT-TTF derivatives possessing hydroxy groups and their achiral and chiral charge transfer complexes

• Sara J. Krivickas,
• Chiho Hashimoto,
• Junya Yoshida,
• Akira Ueda,
• Kazuyuki Takahashi,
• John D. Wallis and
• Hatsumi Mori

Beilstein J. Org. Chem. 2015, 11, 1561–1569, doi:10.3762/bjoc.11.172

• ][17], ethylenedioxy [18], and pyrazino [19]), due to the difficulty of chiral-crystal growth. In order to improve the crystallinity, the inclusion of hydroxy groups in the BEDT-TTF molecule has been postulated to produce hydrogen bonding interactions between electron-donor molecules, electron-acceptor

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF₅-substituted phenylboronic esters and iodobenzenes

• George Iakobson,
• Junyi Du,
• Alexandra M. Z. Slawin and
• Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

• from SF5-aliphatics have also been studied [28][29][30]. The unique combination of properties the SF5 group imparts includes high chemical, thermal, and metabolic stability, strong electron-acceptor property, and high lipophilicity. Furthermore, applications of SF5 compounds in catalysis [31][32], life

• tetrafluoroborates showing that both electron-donor and electron-acceptor substituted phenyldiazonium tetrafluoroborates undergo efficient borylation with an equimolar amount of B2pin2 (Scheme 1); however, ortho-substituted phenyldiazonium salts were found to be either not efficient substrates (3f) or completely

• , iodination with I2 shows a higher sensitivity to electronic properties of substituents on the aromatic ring. Electron-acceptor substituted aryldiazonium compounds are excellent substrates while those with electron-donor groups react much less efficiently. The substitution of pyridine with collidine (2,4,6

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• –tetrathiafulvalenes [14], porphyrin–cyanines [15], porphyrin–carotenes [16], porphyrin–arene diimide [17] and porphyrin–fluorocene or rhodamine [18] have also been synthesized in which the porphyrin unit acts as an electron acceptor. Recently, the 1,2,3-triazole scaffold has been successfully employed to connect

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

• ) presents the same features as the free ligand L2 with a red shift of the different absorption bands (Figure S10 in Supporting Information File 1). The ICT trasnsition suffers a bathochromic shift by about 100 nm as compared with the free ligand which indicates an increase of the electron acceptor effet of

• ). 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

A hybrid electron donor comprising cyclopentadithiophene and dithiafulvenyl for dye-sensitized solar cells

• Gleb Sorohhov,
• Chenyi Yi,
• Michael Grätzel,
• Silvio Decurtins and
• Shi-Xia Liu

Beilstein J. Org. Chem. 2015, 11, 1052–1059, doi:10.3762/bjoc.11.118

• (EPFL), Station 6, CH-1050 Lausanne, Switzerland 10.3762/bjoc.11.118 Abstract Two new photosensitizers featured with a cyanoacrylic acid electron acceptor (A) and a hybrid electron donor (D) of cyclopentadithiophene and dithiafulvenyl, either directly linked or separated by a phenyl ring, were

• -donor (D) and an electron-acceptor (A) unit linked through a π-bridge, leading to a broad and intense optical absorption band in the visible spectral region due to an effective intramolecular charge transfer (ICT) from D to A units. To develop high-efficient DSSCs, a variety of organic donors [2][6][7

• ) configured with DTF-substituted 4,4-dihexyl-4H-cyclopenta[2,1-b:3,4-b’]dithiophene (CPDT) as an electron-donor and cyanoacrylic acid as an electron-acceptor moiety. The incorporation of the rigid and coplanar electron-donating moiety CPDT to the DTF core could increase the electron-donating ability of the

Glycoluril–tetrathiafulvalene molecular clips: on the influence of electronic and spatial properties for binding neutral accepting guests

• Yoann Cotelle,
• Marie Hardouin-Lerouge,
• Stéphanie Legoupy,
• Olivier Alévêque,
• Eric Levillain and
• Piétrick Hudhomme

Beilstein J. Org. Chem. 2015, 11, 1023–1036, doi:10.3762/bjoc.11.115

• control binding interaction towards a strong electron acceptor such as tetrafluorotetracyanoquinodimethane (F4-TCNQ) or a weaker electron acceptor such as 1,3-dinitrobenzene (m-DNB). Keywords: donor–acceptor interactions; glycoluril; molecular clips; supramolecular chemistry; tetrathiafulvalene

• as a π-donating element in molecular clips or tweezers for recognition of neutral electron acceptor guests is still relatively unexplored [13]. Molecular clips and tweezers can be defined as receptors presenting an open cavity composed of two interaction sites which are separated by a spacer [13][14

• and small aromatic electron acceptor molecule. It should be noted that Nolte et al. have successfully observed the complexation of m-DNB using a glycoluril-based receptor bearing 2,7-dimethoxynaphthalene walls (Ka = (115 ± 10) M−1 ) [64]. In the latter case, it was proposed that binding was occurring

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• bromide [90], while usage of noncovalently bound electron-acceptor showed applicability of the phenanthridinium–DNA system for studies of electron transfer in DNA [90]. Thus the EB-nucleobase fluorescence was not sensitive to the type of naturally-occurring adjacent basepairs [90] but showed to be

• -nucleobase was incorporated close to the centre of the DNA oligomer in combination with two different charge acceptors (7-deazaguanine as an electron hole acceptor and a 5-nitroindole as a suitable electron acceptor) [94], showed similar rates and distance dependencies for both, electron and hole transfer

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

• commonly phenyl-C61-butyric acid methyl ester (PCBM), as the electron acceptor [4][5][6][7][8][9]. However, there is growing interest in the use of small molecules as donor materials in OPVs [10][11][12][13][14][15][16][17]. This interest derives from advantages and properties that small molecules show

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

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• that fluorocarbon surfactants exhibit high solubility in scCO2 [26][79]. This is also supported by Reilly et al., who indicated that CO2 is more likely to behave as an electron acceptor over an electron-pair donor, through a study investigating CO2 interactions with d-methanol. Research confirmed that

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• binding behavior between the host and the C60 guest is predominant in solution. The insertion of the π-electron deficient tetrafluoroterephthalic moieties lowers the affinity with the electron acceptor C60 guest, when compared with the reference host 4a (Table 3, entry 1 vs entry 4). This is reasonable as

Organic synthesis using photoredox catalysis

• Axel G. Griesbeck

Beilstein J. Org. Chem. 2014, 10, 1097–1098, doi:10.3762/bjoc.10.107

• -coated semiconductor nanoparticles. On the substrate side, the focus is on redox-active donor/acceptor molecules, which range from all kind of aromatic, olefinic and carbonyl-type electron acceptor compounds to heteroatom-linked electron donors. The relevance of carbon–carbon bond formation for organic

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

• moieties C60 fullerene [43][44][45], and quinones, such as 9,10-anthraquinone as a potential two electron acceptor, have been commonly used in Do–Acc arrangements [46][47][48][49][50][51]. In previous studies phenothiazine–anthraquinone couples have been introduced into peptide scaffolds [52][53][54] and

• multicomponent reactions should as well be applicable to functional Do–Acc dyads. Therefore, we set out to place electron-rich phenothiazinyl and carbazolyl derivatives 4 as amino component in the Ugi 4CR, whereas the electron acceptor was introduced as anthraquinone-2-carbaldehyde (5). Acetic acid (6) and tert

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

• , an electron acceptor and an electron donor leading to energy conversion through electron transfer, was the basis of the so called three-component systems. In this paper, an experimental work combining Rose bengal dye with a triazine derivative as electron acceptor and ethyl 4-(dimethylamino)benzoate

• a dye (PS) with an electron acceptor (A) is depicted. After absorption of actinic light (hν), the PS reaches its singlet excited state (1PS*) and after intersystem crossing (kISC), its triplet excited state (3PS*). From both these excited states, an electron transfer can occur from the PS to A (with

• photolysis quantum yield of 0.19 for RB/TA is obtained. Photocyclic initiating system A typical photocyclic initiating system (PCIS) consists of a light absorbing dye (PS), an electron acceptor (A) and an electron donor (D) (Scheme 3). In such systems, upon irradiation photoinduced electron transfer reaction

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

• photoinitiator catalysts, three possibilities can be briefly considered. The simplest first situation is depicted in Scheme 2. Through light excitation in the presence of an electron acceptor (eA), the oxidized form of the photoinitiator catalyst (PIC•+) is produced. A E-Z compound should be added to recover the

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• 10.3762/bjoc.9.324 Abstract We describe herein the two-component charge-transfer (CT) interaction induced organogel formation with 18β-glycyrrhetinic acid appended pyrene (GA-pyrene, 3) as the donor, and 2,4,7-trinitrofluorenone (TNF, 4) as the acceptor. The use of TNF (4) as a versatile electron acceptor

• electron acceptor, were synthesized and employed to direct the formation of organogels through the CT interaction. Results and Discussion Synthesis As shown in Scheme 1, 18β-glycyrrhetinic acid reacted with 1-pyrenemethylamine in dichloromethane to give the GA-pyrene conjugate 3 with 72% yield. On the

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

• organic molecules such as amines. The photoexcited state is both more oxidizing and more reducing than the ground state. It can be quenched reductively by accepting an electron from an electron donor or oxidatively by donating an electron to an electron acceptor. Amines are often used as an electron donor

• of m-dinitrobenzene (m-DNB) is critical to achieve the desirable conversion and yield of the expected product 32. m-DNB is proposed to act as an electron acceptor to promote an oxidative quenching cycle of Ru(bpy)32+* to Ru(bpy)33+. N-aryltetrahydroisoquinoline 13 is then oxidized by Ru(bpy)33+. This

Electron self-exchange activation parameters of diethyl sulfide and tetrahydrothiophene

• Martin Goez and
• Martin Vogtherr

Beilstein J. Org. Chem. 2013, 9, 1448–1454, doi:10.3762/bjoc.9.164

• S, not N, cast some doubt on whether these reported potentials are the true equilibrium potentials for these irreversible redox systems. In any case, a sensitizer that is a potent electron acceptor but has no hydrogen-abstracting power is mandatory to shift the energetics so as to stop the

Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

• Josué M. Silla,
• Rodrigo A. Cormanich,
• Roberto Rittner and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2013, 9, 1127–1134, doi:10.3762/bjoc.9.125

• boronic acid moiety in organic molecules [5]. Boron has been shown to bind with nitrogen in order to form a ring in 2-(N,N-dimethylaminomethyl)phenylboronic acid [6], thus reflecting its electron acceptor ability through intramolecular interactions. In addition, computational studies have been performed

• orbital in trivalent boron derivatives. This can be useful to mimic vacant orbitals, which are capable of accepting electrons from symmetry-allowed electron donors, such as the σ*OH orbital as an electron acceptor in hydrogen bonding. For example, 4-bromo-2-fluorophenol is supposed to form intramolecular

• 2-fluorophenol a hydrogen bond does not exist according to this approach, because the replacement of σ*OH by a better electron acceptor (empty p orbital) to give the title compounds continues not to show any nF→pB interaction, which is similar to the quantum version for the hydrogen bond nF→σ*OH

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• . Electron-donor and electron-acceptor substituents are tolerated, and polysubstitution can also be successfully accomplished. Experimental Representative experimental procedures for the Cu-catalyzed base-free C–S coupling Method A: The reactions were carried out in a 10 mL two-necked Schlenk tube, equipped