1-(4-Alkyloxybenzyl)-3-methyl-1H-imidazol-3-ium organic backbone: A versatile smectogenic moiety

• William Dobbs,
• Laurent Douce and
• Benoît Heinrich

Beilstein J. Org. Chem. 2009, 5, No. 62, doi:10.3762/bjoc.5.62

• molecules to form spontaneously a single homeotropic monodomain (Figure 5a) the nature of the mesophases could be quite easily assigned on the basis of their optical textures if separated microscope slides (100 μm spacer) were used. The utilization of a spacer allows the formation of large oriented

• identification of all mesophases was supported by small-angle X-ray diffraction. SAXS patterns were collected for the mesomorphic salts as a function of temperature (Figure 6). Typically, in all cases, in the large angle region, i.e. at ca. 4.5–4.6 Å, a very intense and diffuse scattering halo was observed

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

• not show any mesomorphic properties, whereas compounds 2e–i with C9–C13 chains displayed rectangular columnar mesophases and compounds 2j–l with C14–C16 chains displayed hexagonal columnar mesophases. Furthermore an anomalous odd-even effect of the clearing points of compounds 2e–l versus chain length

• 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

• chemistry, asymmetric catalysis and formation of inclusion complexes [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. We have shown that tetraphenylenes with eight peripheral alkoxy or alkanoate chains display thermotropic columnar and smectic mesophases [29

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

• the shape and the symmetry of the mesogenic molecules is giving way to alternative concepts for achieving new molecular and supramolecular motifs able to give rise to dynamic functional properties and unusual topologies and families of mesophases. This goal has been reached through different

• while the half-disc-shaped curcuminoids (B in Figure 2) self-assemble with the formation of columnar mesophases. Moreover, the presence of biologicaly active fragments (the O,O chelating ligands) induces promising anticancer activity in vitro against two human prostatic cancer cell lines in all these

Novel banana-discotic hybrid architectures

• Hari Krishna Bisoyi,
• H. T. Srinivasa and
• Sandeep Kumar

Beilstein J. Org. Chem. 2009, 5, No. 52, doi:10.3762/bjoc.5.52

• models for polymers and networks due to the striking similarity in their transitional behavior and like polymers, some oligomers form glassy mesophases [22][23][24][25][26]. Their purification and characterization are easy unlike polydisperse polymers. Owing to the restricted motion of the components

• interesting physical properties important for device applications. If such architectures could provide columnar mesophases then the charge carrier mobilities are expected to increase owing to the presence of conducting aromatic bent-cores in the otherwise insulating alkyl chain mantle around the discotic

• the other hand, most of the discotic liquid crystalline compounds form columnar phases because of the strong π-π interaction of poly aromatic cores. In the columnar mesophases, the discotic molecules stack one on top of the other to form columns and the columns so formed arrange themselves in various

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• spectrophotometer IR Digital FTS 3000. UV/Vis spectra were recorded with a spectrophotometer U-3000. Elemental analyses were performed by the analytical service at the Institut Charles Sadron and by the analytical service at the Université de Strasbourg (Strasbourg, France). The optical structures of mesophases

Chiral amplification in a cyanobiphenyl nematic liquid crystal doped with helicene-like derivatives

• Alberta Ferrarini,
• Silvia Pieraccini,
• Stefano Masiero and
• Gian Piero Spada

Beilstein J. Org. Chem. 2009, 5, No. 50, doi:10.3762/bjoc.5.50

• efficient chiral inducers in biaryl nematic mesophases. In this paper, we focus on a new series of helicene-like molecules of known absolute configuration. We have integrated cholesteric pitch measurements with geometry optimization by DFT calculations and analysis of the twisting ability by the Surface

• standard Quantum Mechanical (QM) tools. It is known that axially chiral or helical-shaped molecules with reduced conformational disorder are good candidates for high HTP derivatives [2][4][6]. In particular, biaryl derivatives have been described as efficient chiral inducers in biaryl nematic mesophases

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

• group. Structural characterization of the molecules in solution was performed by NMR spectroscopy, UV–vis spectroscopy and cyclic voltammetry. Preliminary studies suggest formation of liquid crystalline (LC) mesophases for some of the prepared dyads. To the best of our knowledge, this is the first

• 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

• Torres and co-workers, who obtained LC mesophases of several phthalocyanine-C60 dyads by blending them with a mesogenic phthalocyanine derivative [45]. In this paper we report the synthesis of the first example, to the best of our knowledge, of mesogenic phthalocyanine-fullerene dyads. Results and

Shape- persistent macrocycle with intraannular alkyl groups: some structural limits of discotic liquid crystals with an inverted structure

• Sigurd Höger,
• Jill Weber,
• Andreas Leppert and
• Volker Enkelmann

Beilstein J. Org. Chem. 2008, 4, No. 1, doi:10.1186/1860-5397-4-1

• to cross the rings and to fill their interior completely. The investigation of the thermal behavior has shown that the smaller cycles do not exhibit thermotropic mesophases. Single crystal x-ray analysis indicates that the anisotropy in these compounds is too small to describe them as plates rather

• mesophases. However, reports about shape-persistent macrocycles with extraannular PAH substituents are absent. If these compounds exhibit liquid crystallinity, the question about the mesogenic element (ring or PAH or both) arises. Additionally, biaxial nematic phases might be observable [31][32]. The

• narrow the temperature range of the mesophase so that for 26 only monotropic mesophases could be observed. It is worth noting that also the attachment of PAH substituents does not in this particular case lead to an observation of an enantiotropic mesophase. This behavior is opposite to a previously