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

• -ray patterns for 1d: (a) isotropic liquid at 160 °C, (b) partially aligned liquid crystalline phase at 120 °C on cooling. The magnetic field is parallel to the meridian of the pattern. 2D X-ray patterns for 1a: (a) isotropic liquid at 150 °C, (b) columnar mesophase at 100 °C, surface aligned on

• cooling, (c) small angle region at 100 °C with reciprocal axes and indices for the 2D lattice of the columnar phase, (d) scattering at 150 °C subtracted from that at 100 °C to enhance the effect of the anisotropic distribution of the diffuse scattering. Model of the molecular packing in the columnar

• mesophase of 1a: (a) 2D packing scheme for the columns in the liquid crystalline phase (plane group p2gg, arbitrary cross section of the columns to fit the symmetry); MMFF calculation (Spartan ’08) of a tetramer of the macrocycles; (b) suggested stacking of the macrocycles within one column (side chains

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• exhibited a rectangular columnar mesophase, while 5b and 5c possessing an ether linkage and a shorter spacer display a hexagonal columnar mesophase. The connecting functional group and the length of the flexible spacer between the central benzene ring and the triphenylene units have pivotal influence on the

• mesomorphism. Keywords: Co2(CO)8 catalyzed cycloaddition; columnar mesophase; discotic liquid crystal; triphenylene; oligomer; Introduction Discotic liquid crystals (DLCs) with nematic phase have been commercially utilized in the liquid crystal display industry as optical compensating films for widening the

• did not crystallize even when cooled to −50 °C. Monomer 3a exhibited a narrow columnar mesophase range between 41 °C to 60 °C for heating, and between 59 °C to 11 °C for cooling. Comparing the phase-transition temperatures of 2 and 3a, it was found that the ester connecting group has the effect 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

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

• ]. Tris(salicylideneanilines) having a discotic shape exhibit a room-temperature columnar mesophase [18][19]. Dendromesogens containing up to 64 peripheral mesogenic salicylideneimine fragments have also been reported [20]. Antiferroelectric behaviour has been claimed by Yablonski et al. to be exhibited

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

• chain derivatives 2j–l (n = 14–16) (shown for 2j in Figure S2 in the Supporting Information). Indeed, as expected the columnar mesophase seems to accommodate the eight bulky gallic esters much better than the smectic layer structure. The crossover from rectangular columnar to hexagonal columnar

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

• derivative [45] allowing the onset, even at room temperature, of a rectangular columnar mesophase which is stable over a very large temperature range (140 °C). The emission properties observed in the solution are preserved in the liquid crystalline state, therefore the flat disk-like molecular structure

• the ancillary ligand. Indeed a transition from a calamitic to a columnar mesophase is observed, through a calamitic/discotic cross-over point, due to the peculiar combination of two different molecular architectures. The mononuclear tropolonate derivative (A in Figure 2) shows a chiral nematic phase

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

• , smectic and columnar phases. On the other hand, the unique geometry of the columnar mesophase formed by discotic liquid crystals is of great importance not only as models for the study of one-dimensional charge and energy migration in organized systems but also as functional materials for device

• differential scanning calorimetry measurements. The absence of either B-phase or discotic columnar mesophase in compound 6 may be explained as follows: since the five-ring banana unit, which otherwise exhibits mesophase with two terminal alkyl chains, is now attached with two bulky triphenylene units at the