Columnar liquid crystalline phases through hydrogen bonding and nanoscale segregation

Abstract

Two columnar phases forming 2,4,6-triarylamino-1,3,5-triazines have been investigated in binary mixtures with calamitic and non-liquid crystalline benzoic acids carrying one or two alkoxy chains at the aromatic core. The triazines form hydrogen bonded aggregates with the complementary acids. Each investigated equimolar mixture exhibits a columnar mesophase due to segregation of the H-bonded polar core region from the lipophilic aliphatic molecular segments. The cross sectional shape of cylindrical aggregates and, therefore, the two-dimensional lattice symmetries, hexagonal or rectangular, are defined by the number of alkoxy chains of the benzoic acid component

Crowded Star Mesogens: Guest‐Controlled Stability of Mesophases from Unconventional Liquid‐Crystal Molecules

“…The higher intensity of the latter at the meridian is relatedt o the intracolumnar separation of the mesogens along the fibre direction. For ac lear comparative discussion, we start the structurala nalysis in the subsequent sections with compound 4b with an intermediate number of aliphatic chains (15), fol-lowed by mesogen 4c with the largest portion of aliphatic chains (18) and conclude with 4a with only 12 chains.…”

“…In the last decade few examples were known in the series of liquid-crystallinem elamine deriva-tives. [15] These molecules, however,w ere only able to accept one guest molecule per mesogen.…”

Induction of Columnar Mesomorphism in Tetracoordinated Ionic Silver(I) Complexes Based on Chelate 4,4'‐Disubstituted 2,2'‐Bipyridines

“…A distortion from Col h to a Col r is obtained when the molecules project an elliptical shape along the column's axis (Figure 4). [14] In this case the presence of the DOS counterion, which because of its shape can be organised with the flexible aliphatic chain aligned in the direction of the aliphatic periphery of the cation, hinders the molecular rotation of the nondisclike molecules, generating an elliptical cross-section. Within the rectangular arrangements, two different symmetries characterised by two different plane groups can be distinguished.…”

Oligomeric liquid crystals: From monomers to trimers

“…A number of differing molecular architectures is possible for liquid crystal trimers; for example, linear [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], terminally/laterally connected [19][20][21], cyclic [22,23], tribranched/star-shaped [24][25][26][27][28][29][30] and mixed calamitic/discotic trimers [19,31,32].…”