The influence of intraannular templates on the liquid crystallinity of shape-persistent macrocycles

• Joscha Vollmeyer,
• Ute Baumeister and
• Sigurd Höger

Beilstein J. Org. Chem. 2014, 10, 910–920, doi:10.3762/bjoc.10.89

• transition of liquid crystalline dimers and bent-core liquid crystals which has recently been identified as a nematic–twist bent nematic (NTB) transition (see, e.g., [59][60]). Therefore the nature of the phase change indicated by the DSC measurements could not be clarified yet. The X-ray pattern for the

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• polarization without molecular tilt has been proved for several materials [35][36][37][38], for which a polar orthogonal smectic A (SmAP) phase has been reported. Additionally to the lamellar phases several two dimensionally (2D) ordered phases of bent-core molecules exist; a columnar structure can be

A new family of four-ring bent-core nematic liquid crystals with highly polar transverse and end groups

• Kalpana Upadhyaya,
• Venkatesh Gude,
• Golam Mohiuddin and
• Rao V. S. Nandiraju

Beilstein J. Org. Chem. 2013, 9, 26–35, doi:10.3762/bjoc.9.4

• Kalpana Upadhyaya Venkatesh Gude Golam Mohiuddin Rao V. S. Nandiraju Chemistry Department, Assam University, Silchar-788011, Assam, India, phone 919435522541, fax 913842270806 10.3762/bjoc.9.4 Abstract Non-symmetrically substituted four-ring achiral bent-core compounds with polar substituents

• , i.e.., chloro in the bent or transverse direction in the central core and cyano in the lateral direction at one terminal end of the molecule, are designed and synthesized. These molecules possess an alkoxy chain attached at only one end of the bent-core molecule. The molecular structure

• -core mesogens; cyanobiphenyl; dipole moment; liquid crystals; nematic phase; polarity; Introduction Following the discovery of chiral and polar properties of mesomorphic bent-core compounds [1][2][3][4][5][6] the area of design, synthesis and properties of banana or bent-shaped liquid crystals (LC

Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

• Govindaswamy Shanker,
• Marko Prehm and
• Carsten Tschierske

Beilstein J. Org. Chem. 2012, 8, 472–485, doi:10.3762/bjoc.8.54

• bent-core mesogens are of special interest for achieving biaxial nematic phases of the orthorhombic type. The orthogonal (NcybA) and skewed (NcybC) cybotactic nematic phases were distinguished by XRD and optical observations. Keywords: bent-core mesogens; cybotactic nematic phases; dimesogen; liquid

• rod-like with discotic [1][9][10], phasmidic or bent-core units, linked together through flexible chains [1]. These flexible chains, which in most cases represent linear alkyl chains, connect the distinct mesogenic units, but depending on their length and degree of flexibility they can also decouple

• ] exhibiting properties that are characteristic for bent-core mesogens, such as polar ferroelectric or antiferroelectric switching LC phases [32][33][34][35] and spontaneous achiral symmetry breaking [34][35][36]. Also dimesogens combining two bent-core units terminally [37][38][39][40][41][42][43] or

Synthesis and mesomorphic properties of calamitic malonates and cyanoacetates tethered to 4-cyanobiphenyls

• Katharina C. Kress,
• Martin Kaller,
• Kirill V. Axenov,
• Stefan Tussetschläger and
• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 371–378, doi:10.3762/bjoc.8.40

• malonates has been devoted to C60 fullerene dendrimers [27][28][29][30][31]. Only a few liquid crystalline cyanoacetates have been described so far. The first example, a dihydrazide, was reported by Schubert [32]. Furthermore some calamitic and bent-core mesogens derived from α-cyanocinnamic acid were

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

• tetragonal), and the so-called banana phases formed by bent-core mesogens [30][34][35]. This review will focus on publications that describe the preparation and characterisation of discrete thermotropic liquid-crystalline nanoparticle hybrids. Thus topics such as micellar [36] or lyotropic NPs [37][38

• bent-core ligands Bent-core mesogens display a bend in their molecular structure (Figure 18), which leads to new packing motifs and provides the possibility of forming mesophases exhibiting polar order and chiral superstructures, even in the absence of any intrinsic chirality. These interesting and

• investigations into the integration of bent-core mesogens into new NP hybrids have been reported. An early report investigated the grafting of bent-core ligands 1410,10 and 1412,11 (Figure 18) to hexanethiol coated Au NPs with diameters of 2.8 ± 0.6 and 2.5 ± 0.5 nm by TEM (3.9 ± 1.5 nm and 2.4 ± 0.8 nm by XRD

Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens

• Sonja Findeisen-Tandel,
• Wolfgang Weissflog,
• Ute Baumeister,
• Gerhard Pelzl,
• H. N. Shreenivasa Murthy and
• Channabasaveshwar V. Yelamaggad

Beilstein J. Org. Chem. 2012, 8, 129–154, doi:10.3762/bjoc.8.15

• , Jalahalli, Bangalore 560 013, India 10.3762/bjoc.8.15 Abstract Bent-core mesogens have gained considerable importance due to their ability to form new mesophases with unusual properties. Relationships between the chemical structure of bent-core molecules and the type and physical properties of the formed

• mesophases are relatively unknown in detail and differ strongly from those known for calamitic liquid crystals. In this paper symmetric and nonsymmetric five-ring salicylideneaniline-based bent-core mesogens are presented, and the effect of lateral substituents attached at the outer phenyl rings (F, Cl, Br

• by differential scanning calorimetry, polarising microscopy, X-ray diffraction and dielectric and electro-optical measurements. The paper reports on new findings with respect to the structure–property relationships of bent-core mesogens. On one hand, the disruptive effect of laterally substituted

Progress in liquid crystal chemistry II

• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 118–119, doi:10.3762/bjoc.8.13

• W. Goodby to find more detailed information [6]. The review articles and original research papers of this second Thematic Series in the Beilstein Journal of Organic Chemistry, written by known experts of their field, cover diverse topics such as novel discotic and calamitic compounds, bent-core

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

• crystalline property probably because of the incompatibility of the bent-core with the discotic core. Keywords: bent-core; dimer; discotic; triphenylene; Introduction Liquid crystals are unique functional self-organized soft materials which possess order and dynamics. Recently, banana liquid crystals or

• properties such as ferroelectric or anti-ferroelectric switching [1][2][3][4][5][6][7]. The occurrence of superstructural chirality in the mesophase of bent-core compounds with no inherent chirality is not only of fundamental scientific interest but also of industrial application as this chirality can be

• ends, the packing of the bent-cores in layers will not be favored. In other words, the bent core-bent core interactions are too weak to produce any B-phase. On the other hand, the two triphenylene units in compound 6 when attached with flexible methylene spacers exhibit columnar mesomorphism. However