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

• by an additional contribution to charge transport from the doped PT backbone [49]. The oxidation of the latter did not contribute significantly to the CV of the polymer films due to the much stronger electrochemical response of the TTF. However, from a separate experiment in which the authors

• of the neutral TTF into a mixed valence state and further to an aggregated cation radical; 2) contrary to formation of the cation radical, the oxidation to the dication is not limited by charge transport through the film as the conductivity of the latter is ensured by both charged TTF species and the

• far in the literature have been discussed. The most interesting properties were exhibited by polymers where TTF units were incorporated alongside the conjugated backbone, allowing for the different charge transport mechanisms on the basis of TTF mixed valence states and polarons to be observed. Upon

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene: the effect of planarisation on charge transport properties

• Rupert G. D. Taylor,
• Joseph Cameron,
• Iain A. Wright,
• Neil Thomson,
• Olena Avramchenko,
• Alexander L. Kanibolotsky,
• Anto R. Inigo,
• Tell Tuttle and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1148–1154, doi:10.3762/bjoc.11.129

• demonstrated that the substitution of thiophene units for thiazoles was found to increase the observed charge transport, which is attributed to induced planarity through S–N interactions of adjacent thiazole nitrogen atoms and TTF sulfur atoms and better packing in the bulk. Keywords: non-covalent

• interactions; organic field effect transistor (OFET); organic semiconductors; tetrathiafulvalene; thiazole; Introduction The TTF moiety has received much attention in the field of organic electronics owing to its reliable redox behaviour [1], good charge transport properties [2] and scope for

• ]. We reasoned that by replacing the terminal thiophene unit with a thiazole moiety, we could induce rigorous planarity throughout the structure and thus improve conjugation, packing and therefore charge transport properties. A typical synthesis of a dithienoTTF is performed convergently: by

Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes

• Luke J. O’Driscoll,
• Sissel S. Andersen,
• Marta V. Solano,
• Dan Bendixen,
• Morten Jensen,
• Troels Duedal,
• Jess Lycoops,
• Cornelia van der Pol,
• Rebecca E. Sørensen,
• Karina R. Larsen,
• Kenneth Myntman,
• Christian Henriksen,
• Stinne W. Hansen and
• Jan O. Jeppesen

Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125

• amidation of aryl halides [51][52]. Examples of TTF derivatives synthesised using this protocol by other groups include: MPTTF and BPTTF-triarylamine conjugates (as possible charge-transport materials) [53], MPTTF-triarylborane conjugates (with possible applications as fluoride sensors) [54], and MPTTF

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

• randomly present because of shuttling of CDs along the π-conjugated chain and remnant water molecules; these affect the charge-transport ability and are disadvantageous for the use of these IMWs as electronic materials. Therefore, we decided to use permethylated cyclodextrin (PMCD) provided by

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

• anions [12]. The result of the IFs high electron affinity is nearly balanced ambipolar charge transport in OFETs [11][13]. The synthetic precursors to 1, the indeno[1,2-b]fluorene-6,12-diones (IF-diones, 2, Figure 1) have also been explored as an active layer in OFETs. The first reported IF-dione OFET

• . Yet again, there is no clear visual trend in the overlap between the symmetric and asymmetric series. Considering that derivatives of 8 are most likely an n-channel material in OFETs, the density and phase of the LUMO should be the most important since in a molecular orbital picture of charge

• transport these are the orbitals that the extra electron would occupy. The Kohn–Sham LUMO density in Figure 3 is predominately located on the indacene moiety and the oxygen. From this perspective the best candidates for n-channel OFET materials would have large overlap between the indacene moiety and oxygen

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

• , drastically alters the solid-state arrangements of the acenes [30]. In certain cases, this leads to a 2D face-to-face “bricklayer” arrangement, which can potentially facilitate charge transport in an electric device by several orders of magnitude [49]. With the understanding that the solid-state packing of

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

• of organization is required to reach good charge transport properties [4][5][6]. However, supramolecular assemblies often suffer from poor stability, meaning that variation of the storage and device operation conditions can perturb the molecular organization, leading to a decline of the materials

Homogeneous and heterogeneous photoredox-catalyzed hydroxymethylation of ketones and keto esters: catalyst screening, chemoselectivity and dilution effects

• Axel G. Griesbeck and
• Melissa Reckenthäler

Beilstein J. Org. Chem. 2014, 10, 1143–1150, doi:10.3762/bjoc.10.114

• advanced synthesis [1][2][3][4][5][6][7][8][9][10]. There are numerous features that characterize an effective photoredox catalytic cycle: light absorption, charge separation, charge transport and annihilation as well as the use of appropriate sacrificial compounds such as electron and hole donors

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

• heterojunction morphology, in which the typical size of the phase-separated domains is about tens of nanometers. The optimal morphology supports efficient charge separation and charge transport in bulk heterojunction solar cells. Our studies showed that the increasing of the alkyl chain length from C1 to C9 had

• content of AIM 7,9 in the blend (1:0.2), the solar cells showed the PCEs below 1% mainly because of low Jsc (3.8 and 3.3 mA/cm, correspondingly). The low content of fullerene acceptor is insufficient for efficient charge transport in the bulk heterojunction as was observed in many other polymer–fullerene

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

• systems represent the fundamental basis for application in molecular electronics and optoelectronics [9][10][11][12][13][14] and they are employed in organic light-emitting diodes (OLEDs) for a balanced charge transport [15][16][17][18][19][20] and photovoltaic devices [21][22][23][24][25]. The concept of

Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

• Peer Kirsch,
• Qiong Tong and
• Harald Untenecker

Beilstein J. Org. Chem. 2013, 9, 2367–2373, doi:10.3762/bjoc.9.272

• isotropic charge transport compared to the “herring bone” stacking observed for other acenes. Keywords: aromatic stacking; charge carrier transport; crystal design; electrostatic control; organic semiconductor; organo-fluorine; Introduction Within a very few years the first organic semiconductors have

• between the neutral species and the charged radical. However, the stacked crystal structure found in acenes in general results in an extremely one-dimensional directionality of charge transport within the single stacks with its inherent vulnerability towards even minor structural defects. Thus, the

• ]. However, the price to pay for this optimized morphology is the presence of bulky silyl groups which do not electronically contribute to the charge transport. For this reason we set out to execute an alternative concept to achieve a brick-like, slipped stacking in planar, acene-based organic semiconductors

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• devices was primarily limited owing to a low fill factor, which was attributed to poorly interconnected domains for charge transport in the cyanopyridone. The N-2-ethylhexyl substituent was employed to enhance the solubility of compound 1 in organic solvents (Figure 1). However, alkylation on the nitrogen

• maintained by introduction of alkyl substituents at the β-position of the thiophenes, and the NH-cyanopyridone unit could be unmasked for hydrogen-bonding. In turn, this may allow access to higher order supramolecular structures, promoting charge transport and increasing the fill factor and efficiency of

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

Liquid-crystalline nanoparticles: Hybrid design and mesophase structures

• Gareth L. Nealon,
• Romain Greget,
• Cristina Dominguez,
• Zsuzsanna T. Nagy,
• Daniel Guillon,
• Jean-Louis Gallani and
• Bertrand Donnio

Beilstein J. Org. Chem. 2012, 8, 349–370, doi:10.3762/bjoc.8.39

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• were focused on improving optical, photovoltaic, and charge-transport properties as well as efficiencies of V-BT derived solar cells. Thus, he studied new processing techniques for solar cells, the use of various semiconducting donor polymers, nanoimprint lithography, etc. [117][118][119][120]. This

Pseudo five-component synthesis of 2,5-di(hetero)arylthiophenes via a one-pot Sonogashira–Glaser cyclization sequence

• Dominik Urselmann,
• Dragutin Antovic and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1499–1503, doi:10.3762/bjoc.7.174

• ; thiophenes; Introduction Over the past decades 2,5-di(hetero)aryl substituted thiophenes [1][2] have constantly attracted a lot of interest, especially as charge-transport materials in electronic [3] and optoelectronic [4][5][6] devices, but also in drug design as antitumor [7] or anti-inflammatory agents

• -iodo-nitrobenzene (1g) a concomitant reduction of the nitro groups to the amines was observed, giving rise to the dianilino thiophene 2g. Most interestingly, even the linear five-ring-containing derivatives “PPTPP” (2n) and “T5” (2o), which are important charge-transport molecules in materials science

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• . The charge transport ability of such elongated fibres of quaterthiophene π-system was explored by the pulse radiolysis time resolved microwave conductivity (PR-TRMC) technique and moderate mobility values were obtained. Furthermore, initial AFM and UV-vis spectroscopic studies of a mixture of our

• electron-rich quaterthiophene derivative with the electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) revealed a nanoscale segregated assembly of the individual building blocks in the blend. Keywords: charge transport; hydrogen bonding; oligothiophene; organogel; self-assembly

• indicates that PCBM does not interfere in the self-assembly of T1. Determination of charge carrier mobility It was anticipated that the well-organized π-stacked assembly of oligothiophene chromophores would provide percolation pathways for charge transport, similar to the previously reported results for

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• for the preparation of highly efficient polymer solar cells [60], some also exhibited ambipolar charge transport [62] with hole and electron transport mobilities up to 0.04 cm2 V−1 s−1 and 0.01 cm2 V−1 s−1, respectively [56]. Characteristic properties of photovoltaic devices are compiled in Table 6

• exhibit ambipolar charge transport with large hole and electron mobilities. Variation of comonomer units or aryl groups in DPP monomers might further improve the device properties. Structure of 3,6-diphenyl-substituted 2,5-diketopyrrolo[3,4-c]pyrrole (DPP). Plot of current density and light intensity

Self-assembled ordered structures in thin films of HAT5 discotic liquid crystal

• Piero Morales,
• Jan Lagerwall,
• Paolo Vacca,
• Sabine Laschat and
• Giusy Scalia

Beilstein J. Org. Chem. 2010, 6, No. 51, doi:10.3762/bjoc.6.51

• long-range charge transport thanks to the spontaneous formation of channels as a result of molecular self-organization into columns and the orbital overlap of neighboring molecules [1][2]. In particular, columnar phases are very appealing for applications since the transport of charges occurs along the

• macroscopic common molecular orientation which can be potentially controlled, thus making it possible to choose the direction of charge flow. Moreover, the degree of molecular order affects the charge transport efficiency, which improves with increasing order. Efforts to improve the electronic performance of

Saddle-shaped tetraphenylenes with peripheral gallic esters displaying columnar mesophases

• Eugen Wuckert,
• Constanze Hägele,
• Frank Giesselmann,
• Angelika Baro and
• Sabine Laschat

Beilstein J. Org. Chem. 2009, 5, No. 57, doi:10.3762/bjoc.5.57

• was detected. Keywords: columnar mesophases; discotic liquid crystals; tetraphenylene; Introduction Columnar liquid crystals have received increasing interest during the last decade due to their 1D charge transport and self-healing properties, which make them particularly promising candidates for

Functional properties of metallomesogens modulated by molecular and supramolecular exotic arrangements

• Alessandra Crispini,
• Mauro Ghedini and
• Daniela Pucci

Beilstein J. Org. Chem. 2009, 5, No. 54, doi:10.3762/bjoc.5.54

• materials with more and more challenging requirements such as improved charge transport, luminescence, chirality and biological functions for high-tech applications has been directed towards the use of new mesomorphic systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Design principles based only on

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

• thermal and photochemical stability [30]. Phthalocyanines bearing flexible peripheral substituents form columnar mesophases [8][31], which demonstrate very efficient charge transport along the columns [32][33]. A unique combination of properties makes phthalocyanines excellent candidates as active