200959-51-9Relevant academic research and scientific papers
Butterfly-like Shape Liquid Crystals Based Fused-Thiophene as Unidimensional Ambipolar Organic Semiconductors with High Mobility
Ma, Tao,Zhong, Yu-Jie,Wang, Hai-Feng,Zhao, Ke-Qing,Wang, Bi-Qin,Hu, Ping,Monobe, Hirosato,Donnio, Bertrand
supporting information, p. 1106 - 1117 (2021/03/26)
Mesomorphous butterfly-like shape molecules based on benzodithiophene, benzodithiophene-4,8-dione and cyclopentadithiophen-4-one core moieties were efficiently synthesized by the Suzuki-Miyaura coupling and Scholl oxidative cyclo-dehydrogenation reactions’ tandem. Most of the butterfly molecules spontaneously self-organize into columnar hexagonal mesophase. The electron-deficient systems possess strong solvent-gelling ability but are not luminescent, whereas the electron-rich terms do not form gels but strongly emit light between 400 and 600 nm. The charge carrier mobility was also measured by time-of-flight transient photocurrent technique in the mesophases for some of the compounds. They display hole-transport performances with positive charge mobility in the 10?3 cm?2 V?1 s?1 range, consistent with the high degree of ordering and stability of the columnar superstructures. In particular, the mesogen with a benzodithiophen-4,8-dione core shows ambipolar charge carrier transport with both high electron (μe=6.6×10?3 cm?2 V?1 s?1) and hole (μh=4.5×10?3 cm?2 V?1 s?1) mobility values.
Molecular design of benzothienobenzothiophene-cored columnar mesogens: Facile synthesis, mesomorphism, and charge carrier mobility
Liu, Chun-Xia,Wang, Hu,Du, Jun-Qi,Zhao, Ke-Qing,Hu, Ping,Wang, Bi-Qin,Monobe, Hirosato,Heinrich, Beno?t,Donnio, Bertrand
supporting information, p. 4471 - 4478 (2018/05/04)
Benzothienobenzothiophene (BTBT) liquid-crystalline semiconductors are arousing a lot of interest due to their long-range ordered, self-organizational abilities and high-charge carrier transport properties. In this work, we report the design and the straightforward synthesis of a homologous series of compounds containing the BTBT substructure by the successive Suzuki cross-coupling and FeCl3 oxidative Scholl cyclodehydrogenation reaction. Target π-conjugated aromatic, H-shaped sanidic mesogens self-organize into a classical hexagonal columnar mesophase over wide temperature ranges as deduced from polarized optical microscopy (POM), differential scanning calorimetry (DSC), and small-angle X-ray scattering (SAXS) investigations. UV/Vis absorption and photoluminescence spectra, measured in both solution and films, revealed strong photoluminescence with high quantum yields. The charge carrier mobility measured by the time-of-flight (TOF) technique showed a balanced ambipolar hole and electron mobility in the range of 10-3 cm2 V-1 s-1 between 100 and 230 °C in the mesophase. These BTBT-based columnar liquid crystals may represent attractive candidates to be incorporated within one-dimensional organic optoelectronic devices.
Thermotropic MIDA Boronates as a Case Study for the Role of Dipolar Interactions in Liquid Crystalline Self-Assembly
W?hrle, Tobias,Gündemir, Rafet,Frey, Wolfgang,Knecht, Friederike,K?hn, Andreas,Laschat, Sabine
supporting information, p. 4149 - 4159 (2017/03/31)
A series of MIDA (N-methylimino diacetic acid) boronates carrying 4-alkoxy, 3,4-bisalkoxy, or 3,4,5-trisalkoxyphenyl substituents were synthesized and their mesomorphic properties characterized by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction (XRD) techniques such as small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). Most derivatives were liquid crystalline. In the case of mono- and bisalkoxy-substituted derivatives, C6 chains already induced smectic A (SmA) mesophases despite the bulky MIDA head group. With increasing chain length, columnar hexagonal (Colh) phases replaced SmA phases in the disubstituted series. Quantum chemical calculations on a series of MIDA boronates show that the B?N bond is a dative bond with a positive charge on the boron atom and negative charges on the nitrogen and oxygen atoms. In addition, no π-interaction between the aryl moiety and B?N bond was found, thus the mesogenic unit is electronically decoupled from the MIDA head group. These theoretical findings were supported by IR and Raman spectra as well as by asingle crystal structure analysis of 4-ethoxyphenyl MIDA boronate. Calculations of the electrostatic potential of the MIDA boronate reveal a special polarity pattern that can support the formation of a two-dimensional network and is likely to explain the liquid crystalline self-assembly. The absence of any electronic cross-talk between the MIDA head group and B-aryl or B-alkyl substituents allows the efficient tailoring of the mesophase type through variation of the substituents.
Discogens Possessing Aryl Side Groups Synthesized by Suzuki Coupling of Triphenylene Triflates and Their Self-Organization Behavior
Zhao, Ke-Qing,Gao, Yue,Yu, Wen-Hao,Hu, Ping,Wang, Bi-Qin,Heinrich, Beno?t,Donnio, Bertrand
, p. 2802 - 2814 (2016/07/07)
Pd-catalyzed Suzuki cross-coupling reactions between arylboronic acids and bromoarenes have been applied widely in the synthesis of liquid-crystalline materials. However, aryl triflate derivatives have been less used despite their high chemical tolerance, reactivity, and chemical accessibility. In this report, three series of discogens have been synthesized in good yields from appropriate triphenylene triflate precursors by Suzuki coupling reactions with various commercial arylboronic acids (e.g., aryl = phenylene, thiophene, naphthalene, triarylamine, carbazole, and fluorene). The synthesized discogens display broad mesophase ranges and high thermal stabilities. Moreover, those bearing triarylamine, carbazole, and fluorene side groups are also blue-light emitters. The availability of the triflate precursors coupled with their highly efficient cross-coupling with commercial arylboronic acids make this strategy extremely versatile and attractive for the design of new functional materials.
Facile bottom-up synthesis of coronene-based 3-fold symmetrical and highly substituted nanographenes from simple aromatics
Zhang, Qiang,Peng, Hanqing,Zhang, Guishan,Lu, Qiongqiong,Chang, Jian,Dong, Yeye,Shi, Xianying,Wei, Junfa
, p. 5057 - 5064 (2014/04/17)
A facile and efficient self-sorting assemble (CSA) strategy has been paved for bottom-up construction of the 3-fold symmetrical and highly substituted hexa-cata-hexabenzocoronenes (c-HBCs), the trithieno analogues, and larger disc-shaped PAHs from simple
New discotic mesogens based on triphenylene-fused triazatruxenes: Synthesis, physical properties, and self-assembly
Zhao, Baomin,Liu, Bo,Png, Rui Qi,Zhang, Kai,Lim, Kheng Aik,Luo, Jing,Shao, Jinjun,Ho, Peter K.H.,Chi, Chunyan,Wu, Jishan
, p. 435 - 449 (2011/10/09)
A new type of discotic mesogen based on triphenylene-fused triazatruxenes was prepared by microwave-assisted 6-fold Suzuki coupling reactions from hexabromotriazatruxene, followed by FeCl3-mediated oxidative cyclodehydrogenation. These disklike molecules showed extended π-conjugation, compared with the triphenylene and triazatruxene themselves. More importantly, they possess desirable HOMO energy levels, which allow efficient charge injection from electrodes such as gold electrodes. Their thermal behavior and self-assembly were studied by different techniques such as thermogravimetric analysis, differential scanning calorimetry, polarizing optical microscopy, and variable-temperature X-ray diffraction. These new discotic mesogens have very good thermal stability and show thermotropic liquid crystalline behavior. Ordered columnar liquid crystalline phase and crystalline phase were observed in both compounds with tunable phase transition temperatures and mesophase widths. The charge carrier mobilities of these extended triazatruxene samples were determined using the space-charge limited-current (SCLC) technique and high hole mobilities of 0.03 and 0.8 cm2 V-1 s-1) were obtained for TP-TATC6 and TP-TATC12, respectively. Interestingly, the long-aliphatic-chain-substituted TP-TATC12 can gelate several nonpolar hydrocarbon solvents or polar aliphatic alcohol and ester solvents, because of strong intermolecular interactions. All these properties qualify this new type of discotic liquid crystals as potential hole transporting materials for electronic devices such as field-effect transistors, light-emitting diodes, and solar cells.
Extended triphenylenes: Synthesis, mesomorphic properties and molecularly resolved scanning tunneling microscopy images of hexakis(dialkoxyphenyl)triphenylenes and dodeca(alkoxy) tris(triphenylenylene)s
Yatabe, Tetsuo,Harbison, Martha A.,Brand, Johann Diedrich,Wagner, Manfred,Muellen, Klaus,Samori, Paolo,Rabe, Juergen P.
, p. 1519 - 1525 (2007/10/03)
Palladium-catalyzed cross-coupling between 3,4-dialkoxyphenylboronic acids (1a-d) and 2,3,6,7,10,11-hexabromotriphenylene (2) provided 2,3,6,7,10,11-hexakis[3,4-bis(alkoxy)phenyl]triphenylenes, C18H6[C6H3(OC(n)H(2n + 1)2]6 where n = 6, 8, 10, and 12 (3a-d). Cyclodehydrogenation of the aryl-substituted triphenylenes 3a-d using ferric chloride oxidation followed by methanol reduction produced 6,6',6'',7,7',7'',10,10',10'',11,11',11''-dodecaalkoxy-2,3':3,2':2',3''- tris(triphenylenylene)s, C54H18(OC(n)H(2n + 1))12 where n = 6, 8, 10, and 12 (4a-d). The mesomorphic properties of the compounds 3a-d and 4a-d were investigated by differential scanning calorimetry (DSC) measurements, polarizing microscopy, and wide angle X-ray diffraction (WAXD). The triphenylenes 3a-d exhibited a columnar mesophase in the range of 111-126, 85-104, 74-103, and 47-101 °C, respectively. Upon oxidation of the moiety, the columnar mesophases shift to higher temperatures and exist in a much broader range of temperatures: for the tris(triphenylenylene)s 4a-d, they have been observed in the range of 180-430, 150-370, 120-322, and 104-306 °C, respectively. Finally, the self-assembly at the interface between a solution of 4c and a graphite substrate has been studied by scanning tunneling microscopy. Molecularly resolved imaging revealed a highly ordered monolayer exhibiting a two-dimensional hexagonal lattice.
Convenient synthesis of a discotic side group liquid crystal polymer
Stewart, David,McHattie, Gillian S.,Imrie, Corrie T.
, p. 47 - 51 (2007/10/03)
The synthesis of a discotic side group liquid crystal polymer based on poly (methyl methacrylate) is reported. This involves the oxidative coupling of 3,3′,4,4′-tetrakis(hexyloxy)biphenyl with 1-hexyloxy-2-methoxybenzene to yield the unsymmetrical triphenylene nucleus, 2-methoxy-3,6,7,10,11-pentakis(hexyloxy)triphenylene. Subsequent demethylation followed by reactions first with 1,11-dibromoundecane and then with the potassium salt of methacrylic acid yielded the polymerisable monomer, 11-[3,6,7,10,11-pentakis(hexyloxy)-2-oxytriphenylene]undecyl methacrylate. This was polymerised in benzene using azoisobutyronitrile as the initiator. The thermal properties of the resulting polymer are described.
