Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells

• Hideaki Komiyama,
• Chihaya Adachi and
• Takuma Yasuda

Beilstein J. Org. Chem. 2016, 12, 1459–1466, doi:10.3762/bjoc.12.142

• (OPERA), Kyushu University 10.3762/bjoc.12.142 Abstract Solution-processable star-shaped and linear π-conjugated oligomers consisting of an electron-donating tetrathienoanthracene (TTA) core and electron-accepting diketopyrrolopyrrole (DPP) arms, namely, TTA-DPP4 and TTA-DPP2, were designed and

• TTA-DPP2 with a fullerene derivative were evaluated by varying the thickness of the bulk heterojunction active layer. As a result of the enhanced visible absorption properties of the star-shaped π-conjugated structure, better photovoltaic performances were obtained with relatively thin active layers

• ability, and good miscibility with a fullerene derivative as an acceptor. Moreover, strong visible light photoabsorption ability for visible light is vital for the donor materials. Star-shaped molecules tethering multiple π-conjugated arms are capable of harvesting incident light effectively owing to

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

• ]. As a consequence, it was envisaged that the fullerene derivatives with smaller π-conjugated area would interact less strongly with the stationary phase of the column and therefore elute faster than derivatives with larger π-surface. In addition, the substitution on fullerenes may block the

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

• Minh Anh Truong Koji Nakano Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan 10.3762/bjoc.12.79 Abstract Ladder-type π-conjugated compounds containing a benzo[2,1-b:3,4-b']difuran skeleton, such

• far reported, thiophene-fused π-conjugated compounds have been widely studied as organic semiconducting materials and found to exhibit high semiconducting performances [5][13][14][15][16]. Furan-containing π-conjugated compounds have attracted less attention until recently [17][18][19][20][21][22][23

• ][24][25][26][27]. The oxygen atom possesses a smaller van der Waals radius than a sulfur atom. Accordingly, furan-containing π-conjugated compounds should be expected to form a denser packing structure in the solid state, which is one of the main requirements for high semiconducting properties [28][29

Synthesis and photophysical characteristics of polyfluorene polyrotaxanes

• Aurica Farcas,
• Giulia Tregnago,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert and
• Franco Cacialli

Beilstein J. Org. Chem. 2015, 11, 2677–2688, doi:10.3762/bjoc.11.288

• wide variety of host molecules have the ability to encapsulate the π-conjugated backbones into their cavities based on intermolecular interactions, and thus leading to ICs. Cyclodextrins (CDs) are by far the most intensively investigated macrocyclic molecules in the synthesis of such supramolecular

Efficient synthesis of π-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp²)–H bond arylations

• Fatiha Abdelmalek,
• Fazia Derridj,
• Safia Djebbar,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2015, 11, 2012–2020, doi:10.3762/bjoc.11.218

• , 15000 Tizi-Ouzou, Algeria Laboratoire d’hydrométallurgie et chimie inorganique moléculaire, Faculté de Chimie, U.S.T.H.B. Bab-Ezzouar, Algeria 10.3762/bjoc.11.218 Abstract We report herein a two or three step synthesis of fluorinated π-conjugated oligomers through iterative C–H bond arylations

• regioselective activation of C(sp2)–H bonds. Keywords: catalysis; C–H bond arylations; desulfitative; fluorine; palladium; Introduction Fluorinated π-conjugated oligomers increasingly receive recent interest owing to their particular applications as electronic devices (e.g., in organic solar cells) [1][2][3][4

• dramatically influence both chemical properties and reactivities owing to its electronegativity, size, lipophilicity, and electrostatic interactions. For example, introduction of fluorine into natural products can result in beneficial biological properties [6]. On the other hand, fluorinated π-conjugated

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

• systems [35] including incorporation within the conjugated backbone [36][37], as a pendant unit [38][39][40] and direct fusion to the π-conjugated system of the polymer [41][42]. Incorporation of a TTF unit into a PT architecture allows the creation of interesting hybrid redox systems with a wide range of

• , the polymer 34 exhibited an absorption band with a maximum at ca. 490 nm and extending to ca. 736 nm, with an optical band gap of 1.69 eV (Table 2). For a simple π-conjugated polymer the difference between the oxidation and reduction onsets constitute the electrochemical band gap [74][75]. For polymer

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

• -diethynylxanthen-9-one. In addition, a new series of various β-triazole-linked porphyrin–xanthone conjugates and xanthone-bridged triazoloporphyrin dyads were synthesized through click chemistry in moderate to good yields. The preliminary photophysical evaluation of these π-conjugated molecules revealed a

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

• proton resonances of L1 or L2 exhibit an upfield shift. These results tend to be consistent with the deprotonation of the N–H group and the delocalization of the negative charge over the π-conjugated system as previously observed TTF dinitrophenylhydrazone [36]. Note that there is no change in the 1H NMR

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• ) [104][105][106]. Among the π-conjugated systems stilbene derivatives found a unique place in materials science due to their optical and charge conducting properties. Tsuge and co-workers [107] reported the synthesis of stilbene 88 by using the McMurry coupling and studies on the transmission of the

• syntheses of 100 molecules by using the McMurry reaction followed by hydrogenation. Pei and co-workers [120] have synthesized anthracene-based π-conjugated strained cyclophane 101 by using an intramolecular McMurry reaction. The combination of unsaturated linkages in these molecules might create a twisted

• derivative 159 (Scheme 24). To prepare π-conjugated three-dimensional molecules with potential isoelectronic properties and facile processibility, Kurata and co-workers [146] reported sexithiophene 163, a bridged cage shaped compound (Scheme 25). Its synthesis involves a Suzuki–Miyaura coupling reaction

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F₄TCNQ

• Raúl García,
• M. Ángeles Herranz,
• Edmund Leary,
• M. Teresa González,
• Gabino Rubio Bollinger,
• Marius Bürkle,
• Linda A. Zotti,
• Yoshihiro Asai,
• Fabian Pauly,
• Juan Carlos Cuevas,
• Nicolás Agraït and
• Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

• end [15][16]. Furthermore, extended TTF cruciform molecules, formed by two orthogonally placed, π-conjugated moieties bearing the 1,3-dithiole rings at the ends, have also been used for single-molecule measurements [17]. A singular TTF analogue is the so-called π-extended TTF (exTTF, (9,10-bis(1,3

A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles

• Roman A. Irgashev,
• Arseny A. Karmatsky,
• Gennady L. Rusinov and
• Valery N. Charushin

Beilstein J. Org. Chem. 2015, 11, 1000–1007, doi:10.3762/bjoc.11.112

• into account that the overwhelming majority of compounds for organic electronics are constructed from π-conjugated linear or angular fused aromatic and heteroaromatic units [16][17][18][19], the development of convenient synthetic ways to structures bearing several linked (het)aromatic units appears to

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• carried out by direct C–H activation of the TTF unit, and the chiroptical properties of the resulting polymer were also investigated. Keywords: allene; axial chirality; chiroptical properties; redox; tetrathiafulvalene; Introduction Recently, there has been a growing interest in chiral π-conjugated

• -diphenyl allene unit [15]. In addition, Fallis and co-workers synthesized a cyclic oligoallene based on a chiral 1,3-diphenylallene [16]. More recently, Kijima and co-workers reported the use of a racemic 1,3-diphenylallene framework as a new building block for a π-conjugated polymer [17]. However, there

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

• Yunfei Wang and
• Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

• surging research activities on integrating TTFVs into a variety of π-conjugated molecular and macromolecular systems [12][17][18][19][20][21][22][23][24][25][26]. In many of the studies, the remarkable redox activity and intriguing conformational switching properties of TTFVs were taken advantage of to

• oxidative dimerization reaction of corresponding dithiafulvene (DTF) precursors [27]. This straightforward C–C bond forming reaction has not only allowed TTFV derivatives with different substituents to be readily assembled, but served as an effective methodology to construct the π-conjugated frameworks of

• some TTFV-based macrocycles and polymers [12][28]. Previously, we have investigated a series of diphenyl-TTFVs with alkynyl groups attached to the phenyl units as synthetic building blocks, through which extension of π-conjugated structures could be conveniently executed via the Pd-catalysed coupling

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• ; tetraethynylethene; tetrathiafulvalene; Introduction Linking together two redox-active tetrathiafulvalene (TTF) units by a π-conjugated bridge has found immense interest in materials science, in particular in the quest for organic conductors [1][2][3]. Thus, the materials properties rely on the degree of intra- and

• -energy bands to charge-transfer absorptions, which are usually observed in π-conjugated systems containing TTF donors and large acetylenic scaffolds that behave as electron acceptors [8][9][10]. The significant redshifts of the charge-transfer absorptions experienced for 8 and 2a relative to the

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

• stretching mode (at 1459 cm−1) is observed with a shoulder appearing at 1441 cm−1 while the two less intense bands appear at 1496 and 1373 cm−1. The broadening of the spectra in P3T is related to its branched architecture with different conjugation paths along their π-conjugated backbones which also results

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

• develop oxidative transformations of aromatic amines for the construction of diverse aza-containing π-conjugated functional molecules [27][28][29][30], we have recently discovered an iodine-containing oxidant-induced unusual oxidative rearrangement of BINAMs leading exclusively to U-shaped azaacenes

• . Herein we present a facile, straightforward, and moderately functional-group-tolerant synthesis of 7,8-diaza[5]helicenes (benzo[f]naphtho[2,1-c]cinnolines) bearing functional substituents on the helical π-conjugated backbone through an oxidative ring-closure of BINAM derivatives (Scheme 2, the lower

Synthesis of an organic-soluble π-conjugated [3]rotaxane via rotation of glucopyranose units in permethylated β-cyclodextrin

• Jun Terao,
• Yohei Konoshima,
• Akitoshi Matono,
• Hiroshi Masai,
• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2014, 10, 2800–2808, doi:10.3762/bjoc.10.297

• -phenylene) and oligothiophene with a pseudo-linked [3]rotaxane structure by full rotation of glucopyranose units via a flipping (tumbling) mechanism in the π-conjugated guest having two permethylated β-cyclodextrin units at both ends. We also succeeded in the synthesis of an organic-soluble fixed [3

• ]rotaxane by a cross-coupling or complexation reaction of thus formed pseudo linked [3]rotaxane. Oligo(para-phenylene), oligothiophene, and porphyrin derivatives were used as π-conjugated guests with stopper groups. Keywords: cross-coupling reaction; insulated π-conjugated molecule; oligothiophene

• ; permethylated cyclodextrin; [3]rotaxane; Introduction Insulated molecular wires (IMWs) [1][2], which feature π-conjugated polymer chains covered by protective sheaths, have attracted considerable attention as next-generation mono-molecular electronic devices because of their potential conductivity and

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

• unit derivatives substituted with oligothiophenes at the meso-position [47]. Thus, the incorporation of two extra thiophene rings, and connection to the DPP core, does not affect the absorption peak associated with the BODIPY units. On the other hand, the extension of the π-conjugated system

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

• granular morphology with a lower dispersity supported by a smaller roughness exponent compared with the non-rotaxane counterpart. Keywords: cyclodextrins; energy band gaps; fluorescence lifetimes; persilylated cyclodextrins; supramolecular encapsulation; surface morphology; Introduction Semiconducting π

• -conjugated polymers have attracted attention in the last years as promising active hole-transporting materials, which have a wide range of applications in electro-optical devices [1][2][3][4]. Polyfluorenes (PFs) are the most often investigated semiconducting polymers and are considered promising candidate

Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

• Simon Rondeau-Gagné,
• Jules Roméo Néabo,
• Maxime Daigle,
• Katy Cantin and
• Jean-François Morin

Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167

• π-conjugated monomers capable of hydrogen bonding to create nanowires [21][22][23], nanoparticles [24][25][26][27], nanotubes [28][29][30][31] and two-dimensional layered materials [32] from organogels. The key to success was to obtain a good balance between solubility and gelation properties

Palladium-catalysed cross-coupling reaction of ultra-stabilised 2-aryl-1,3-dihydro-1H-benzo[d]1,3,2-diazaborole compounds with aryl bromides: A direct protocol for the preparation of unsymmetrical biaryls

• Siphamandla Sithebe and
• Ross S. Robinson

Beilstein J. Org. Chem. 2014, 10, 1107–1113, doi:10.3762/bjoc.10.109

• π-conjugated organic molecules containing a three-coordinate boron moiety such as trimesitylborane (4), arylalkynyldimesitylborane 5 and 2-aryl-1,3-diethyl-1H-benzo[d]1,3,2-diazaborole 6 (Figure 2) are well known and have received considerable attention due to their interesting luminescence

• as NO2, OMe, COMe and diazaborolyl whilst furnishing the coupled product with isolated yields of up to 96% in only 10 minutes. Structures of organoboron compounds 1–3. Structure of π-conjugated three-coordinate organoboron compounds 4 and 5. Synthesis of 2-aryl-1,3-dihydro-1H-benzo[d]-1,3,2

cis–trans Isomerization of silybins A and B

• Michaela Novotná,
• Radek Gažák,
• David Biedermann,
• Florent Di Meo,
• Petr Marhol,
• Marek Kuzma,
• Lucie Bednárová,
• Kateřina Fuksová,
• Patrick Trouillas and
• Vladimír Křen

Beilstein J. Org. Chem. 2014, 10, 1047–1063, doi:10.3762/bjoc.10.105

• analogues are considered to be composed of two separate π-conjugated subsystems, the 3-hydroxyflavonone moiety (with the stereogenic centers C-2 and C-3), and the 1,4-benzodioxane moiety (C-10 and C-11) (see Figure 4). In this simplification we cannot avoid the adverse effects caused by neglecting the

• obtained by the isomerization of 1 using BF3·OEt2 in EtOAc. ECD spectrum of silybin B (1b) and its separation (in a crude approximation) into two π-conjugated moieties (3-hydroxyflavonone with stereogenic centers C-2, C-3 (in blue) and 1,4-benzodioxane with C-10,C-11) (in red) according to [2]. Synthetic

Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• aromatic hydrocarbons – possess unique physical properties due to their curved π-conjugated systems [1][2][3][4][5]. One of these characteristic features is a columnar packing structure in the crystal state. Many buckybowls, including sumanene [2], exhibit columnar packing in which the bowl-shaped

• of the columns: unidirectional (Figure 1a) and opposite (Figure 1b). These columnar structures allow buckybowls to exhibit specific solid-state properties, including high electron conductivity and solid-state emission [14][15][16][17][18]. In contrast, planar π-conjugated aromatic compounds tend to

• ) unidirectional and (b) opposite structures, in addition to (c) the herringbone packing structure typical of planar π-conjugated compounds. The X-ray crystal structure of 1, showing: (a) top view of the ORTEP drawing with 50% probability, b) side view, c) top view of the packing structure with the sumanene bowl

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• the photocatalytic oxidative activation of NHPI by graphitic carbon nitride (g-C3N4) and visible light irradiation [65]. g-C3N4, the most stable allotrope of carbon nitride, is a two-dimensional polymer with a tri-s-triazine ring unit and a π-conjugated layered structure similar to graphene. It is a

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• radical acceptors in this addition. Studer’s stannylphosphine technology is reliable enough to be applied to the construction of interesting π-conjugated frameworks. In collaboration with Yamaguchi, Studer invented a new radical reagent (Me3Sn)2PPh for the synthesis of highly strained bis(phosphoryl

• )-bridged biphenyls (Scheme 20) [46]. Subsequently, Liu reported an efficient synthesis of bis(phosphoryl)-bridged ladder triphenylene by means of the radical clipping with (Me3Sn)2PPh (Scheme 21) [47]. In light of the increasing importance of phosphoryl-bridged π-conjugated skeletons in organic material