Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• chromatography. The extension of π-conjugation by a palladium-catalyzed cross-coupling reaction after a tetramerization reaction proceeds with high yield. Furthermore, since TFEO-Pcs are not only easy to purify but also do not aggregate, their identification by NMR, MS, UV–vis and IR is easy. Consequently

• [75][76]. However, phthalocyanine dimers with high rigidity and flatness exhibit a stronger aggregation effect as π-conjugation expands. For example, a tert-butyl-substituted phthalocyanine dimer connected via diacetylene linker (9) strongly aggregates in solution although tert-butyl-substituted

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• the inter-ring C–C bond, resulting in a loss of effective π-conjugation as well as the Raman peaks associated with highly ordered polymer phases (in particular the lower energy contribution to the main C=C peak) [42]. The temperature dependent Raman spectra of the diblock and blend films presented in

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• match of experimentally and computationally determined absorption bands cannot be expected for conformationally flexible complex molecules with extended π-conjugation, the trend of the longest wavelength absorption bands from the UV–vis spectra is correctly reproduced. Furthermore, for all three methods

Effect of the π-conjugation length on the properties and photovoltaic performance of A–π–D–π–A type oligothiophenes with a 4,8-bis(thienyl)benzo[1,2-b:4,5-b′]dithiophene core

• Ni Yin,
• Lilei Wang,
• Yi Lin,
• Jinduo Yi,
• Lingpeng Yan,
• Junyan Dou,
• Hai-Bo Yang,
• Xin Zhao and
• Chang-Qi Ma

Beilstein J. Org. Chem. 2016, 12, 1788–1797, doi:10.3762/bjoc.12.169

• ], thienyl group [16][17][18], and thienothiophene [17][19]. Structure modifications of the BDT core with aromatic units extend the π-conjugation of BDT unit to a two-dimensional structure, which increases intermolecular interactions, and consequently improves the device performance. The other one is to

• characterization of BDT derivatives based on oligothiophene π-bridges with more than three thiophene units [27], where symmetric quater- and quinquethiophenes were used as the π-conjugation bridge. Surprisingly, the quaterthiophene-bridged compound showed the worst photovoltaic performance when blending with a

• fullerene derivative as the photoactive layer. This was ascribed to the influence of the orientation of the alkyl side chains. Although regioregular oligo(3-alkylthiophene)s are better building blocks for studying the effect of the π-conjugation length, only regioregular terthiophene (rr-3T) was reported to

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• -difluoro-2H-benzo[d][1,2,3]triazole (Tz) have attracted much attention and effectively employed in BHJ PSCs due to their intrinsic advantages, potentials and versatility [14][15]. Thanks to the desirable properties such as structural rigidity, planarity, extended π-conjugation length and favorable

• interchain π–π stacking, BDT is a widely used electron-rich monomer. Moreover, alkyl or aryl groups can easily be introduced to BDT basic units as side groups to finely tune the properties of the resulting polymers, not only in terms of solubility but also contributing, for example, to extend the π

• -conjugation from the backbone to the lateral substituent (2D π-conjugated systems), thus leading to a bandgap reduction and higher charge carrier mobilities [15][16][17][18]. On the other hand, the Tz moiety, usually sandwiched between adjacent thiophene spacers to limit the inter-monomers steric hindrance

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

• semiconducting properties [36][37]. For example, dialkyl-substituted anti-DBBDF 3 showed a hole mobility of 0.042 cm2·V−1·s−1 [38]. Recently, we have also found that dinaphtho[2,3-d:2',3'-d']benzo[1,2-b:4,5-b']difuran (anti-DNBDF 4) with a more extended π-conjugation afforded higher hole mobility of 0.33 cm2·V−1

• the π-conjugated skeleton than syn-DBBDF 5, it should possess an extended π-conjugation length, resulting in a red-shifted absorption spectrum. The HOMO–LUMO energy gaps estimated from the absorption edges were 3.72 eV and 3.32 eV for syn-DBBDF 5 and syn-DNBDF 6, respectively. Their photoluminescence

• showed one oxidation wave with an onset potential of 0.56 eV (vs Fc/Fc+, HOMO = −5.36 eV). The lower oxidation potential and higher HOMO energy level of syn-DNBDF 6 should reflect its longer π-conjugation length than syn-DBBDF 5. Based on their HOMO energy levels and HOMO−LUMO energy gaps, syn-DBBDF 5

Direct estimate of the internal π-donation to the carbene centre within N-heterocyclic carbenes and related molecules

• Diego M. Andrada,
• Nicole Holzmann,
• Thomas Hamadi and
• Gernot Frenking

Beilstein J. Org. Chem. 2015, 11, 2727–2736, doi:10.3762/bjoc.11.294

• which previously ascribed to stronger π-conjugation [105][106][107]. The introduction of the heteroatoms O and S in compounds 11 and 12 changes the C–N bond only slightly. The Ccarb–C bond lengths in the conjugated carbenes are between 1.404 Å (9)–1.433 Å (14) while the cAAC system 6 has a much longer

[2.2]Paracyclophane derivatives containing tetrathiafulvalene moieties

• Laura G. Sarbu,
• Lucian G. Bahrin,
• Peter G. Jones,
• Lucian M. Birsa and
• Henning Hopf

Beilstein J. Org. Chem. 2015, 11, 1917–1921, doi:10.3762/bjoc.11.207

• (Figure 1). The molecular dimensions confirm the extensive p–π conjugation within the dithiocarbamate group; the N(1)–C(19) bond length is 1.341(3) Å, some 0.12 Å shorter than N(1)–C(20) and N(1)–C(21), which are essentially σ-bonds. The cyclophane group displays the usual indicators of strain (e.g

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• derivatives, radially expanded or star-shaped multi-TTFs with C3 and C6 symmetries have attracted considerable attention in the field of materials science because of their divergent and extended π-conjugation. Various C3-symmetric compounds incorporating three conjugated TTF units were designed and

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

• phenyl spacer. Without a phenyl ring, the D unit appears more difficult to oxidize due to a strong electron-withdrawing effect of the A moiety. In sharp contrast, the insertion of the phenyl ring between the D and A units leads to a broken π-conjugation and therefore, the oxidation potentials remain

• HOMO–LUMO gap. In turn, the direct linkage of D and A units leads to an effective π-conjugation, thus substantially lowering the HOMO–LUMO gap. Moreover, the application in dye-sensitized solar cells was investigated, showing that the power conversion efficiency increases by the insertion of the phenyl

• effect of the cyanoacrylic acid. Obviously, the electronic interaction between D and A units is fairly weak because the π-conjugation is partially broken upon the insertion of the phenyl ring which can adopt a non-coplanar conformation. In contrast to 2, 1 is much more difficult to oxidize as its

Self-assembly of heteroleptic dinuclear metallosupramolecular kites from multivalent ligands via social self-sorting

• Christian Benkhäuser and
• Arne Lützen

Beilstein J. Org. Chem. 2015, 11, 693–700, doi:10.3762/bjoc.11.79

• that is very unfavorable for the formation of discrete metallomacrocyclic assemblies upon coordination to a metal ion that prefers a tetrahedral coordination by two chelating ligands. The same is true for ligand 2 which adopts a flat conformation to maximize π-conjugation. To form a macrocyclic

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

• Erdal Ertas,
• İlknur Demirtas and
• Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

• studied and has had the largest number of radical cation salts of its CT materials investigated at very low temperature [12][21][22][23][24]. In order to improve the properties of TTF type materials, various methods have been applied, including extension of π-conjugation through double bonds [25][26][27

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

• 1500 cm−1 in P(EDOT-co-3T)-1:1) and the Cβ–Cβ Raman bands (from 1368 in PEDOT/P3T-blend to 1364 cm−1 in P(EDOT-co-3T)-1:1). This frequency downshift strongly suggests that the copolymer has an improved π-conjugation because of the better π-electron delocalization through the covalently connected 3T and

• improves the conjugation length. This can be ascribed to the significant participation of the oxygen atoms in the π-conjugation and a gain in rigidity of the polymer backbone due to intramolecular sulfur–oxygen interactions [55][56]. The asymmetric Cα=Cβ stretching modes upshift and increase in intensity

2-(1-Hydroxypropyn-2-yl)-1-vinylpyrroles: the first successful Favorsky ethynylation of pyrrolecarbaldehydes

• A. V. Ivanov,
• V. S. Shcherbakova,
• I. A. Ushakov,
• L. N. Sobenina,
• O. V. Petrova,
• A. I. Mikhaleva and
• B. A. Trofimov

Beilstein J. Org. Chem. 2015, 11, 228–232, doi:10.3762/bjoc.11.25

• -vinyl group; (iii) the vinyl group is an electron-withdrawing substituent relative to the pyrrole ring acting both via inductive and π–π conjugation mechanisms that should increase the electrophilicity of the carbonyl group; (iv) the N-vinyl group essentially extends the reactivity and hence potential

Photorelease of phosphates: Mild methods for protecting phosphate derivatives

• Sanjeewa N. Senadheera,
• Abraham L. Yousef and
• Richard S. Givens

Beilstein J. Org. Chem. 2014, 10, 2038–2054, doi:10.3762/bjoc.10.212

• rearrangement processes for pHP. Wan’s alternative suggestion that a disruption of both aromatic rings' π-conjugation would be less favorable than only one ring’s disruption has merit. For this to be a determining factor, the disruption would have to occur prior to or during the product determining formation of

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

• unidirectional columnar structures based on π–π stacking while the pyrene moieties generate herringbone structures due to CH–π interactions. The absorption and emission maxima of pyrenylsumanene were both red-shifted relative to those of sumanene and pyrene, owing to the extension of π-conjugation. Monomer

• ). The dihedral angle between the sumanene and pyrene moieties resulting from calculations was 48.2°. This angle causes some extension of the π-conjugation to the sumanene moiety, resulting in a narrower HOMO–LUMO gap and the observed red shift in absorption. The emission of 1 in solution is also red

First synthesis of meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2014, 10, 808–813, doi:10.3762/bjoc.10.76

• ]quinoxalinoporphyrins; Pictet–Spengler reaction; synthesis; Introduction Many natural porphyrins are known to play essential roles in a number of biological processes including oxygen transport [1], solar energy conservation [2][3][4] and photosynthesis [5]. Owing to the expanded π-conjugation system as well as good

High-spin intermediates of the photolysis of 2,4,6-triazido-3-chloro-5-fluoropyridine

• Sergei V. Chapyshev,
• Denis V. Korchagin,
• Patrik Neuhaus and
• Wolfram Sander

Beilstein J. Org. Chem. 2013, 9, 733–742, doi:10.3762/bjoc.9.83

• associated with strong π-conjugation of these groups with the pyridine ring. On photoexcitation, such azido groups are more efficiently involved in reorganization of the molecular electronic system and more easily adopt geometries of the locally excited predissociation states. Keywords: azides; EPR

• fluorine atom of pyridines. On comparison with the chlorine, the fluorine is a much more electron-negative and less bulky atom. Both of these factors favor strong π– conjugation of the ortho-azido groups with the pyridine ring. On photoexcitation, such azido groups should be more efficiently involved in

• -positions to the fluorine atom of pyridines is associated with strong π-conjugation of these groups with the pyridine ring. On photoexcitation, such azido groups are more efficiently involved in reorganization of the molecular electronic system and more easily adopt geometries of the locally excited

A new intermediate in the Prins reaction

• Shinichi Yamabe,
• Takeshi Fukuda and
• Shoko Yamazaki

Beilstein J. Org. Chem. 2013, 9, 476–485, doi:10.3762/bjoc.9.51

• TS1(Ph). A noticeable difference is found in the contrast of the stability order, ene-ol(Ph) > ether(Ph) versus ene-ol(Me) < ether(Me). The 3-phenyl-2-propenol (cinnamyl alcohol) is an allylic alcohol with the π conjugation of the phenyl ring and is thought to be the source of the stability of ene-ol

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• materials with extended π-conjugation have attracted considerable attention in recent years as a new class of active organic materials for optoelectronic applications [1][2][3][4]. Among the conjugated polymers, a number of poly(9-alkylfluorene)s (PFs) and poly(9,9-dioctylfluorene) (PDOF) polymers in

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

• process for the open-ring isomers 1o–3o occurs at higher potentials than in the corresponding closed-ring isomers 1c–3c. This was because the longer conjugation length of the closed-ring isomers generally leads to a less positive potential [62][65]. The cyclization reaction allows the π-conjugation to

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• -component approach to heterocyclic derivatives of azulene is well suited for the development of functional chromophores with extended π-conjugation. Selected resonance structures of azulene (1a) and structure of the sesquiterpene guaiazulene (1b). Synthesis of ynones by glyoxylation–decarbonylative

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

• monomer (Figure 4). The same coupling reaction of M-4 resulted in polymer P-22, its π-conjugation being interrupted at the N-lactam units. Consequently, the absorption and emission behaviour were not much different from the corresponding monomer, the band gaps of the two isomers being 2 and 2.3 eV