Design of New Mesogenic Block Molecules: Formation of Columnar Mesophases by Calamitic Bolaamphiphiles with Lateral Lipophilic Substituents

Abstract

Rigid bolaamphiphiles with lateral alkyl chains such as 1 form columnar mesophases of a novel type based on microsegregation of the three incompatible parts of the molecules (shown schematically).

Dissipative particle dynamics simulation of quaternary bolaamphiphiles: multi-colour tiling in hexagonal columnar phases

“…This means that, as the chain length is increased, various different columnar structures can be observed, depending on the required volume to rod length ratio. Thus on increasing the chain length, columnar phases with square, (skewed) pentagonal and hexagonal cross sections have been observed, [1][2][3][4][5][6] followed by either columnar phases with more complex tiling patterns or lamellar phases. 7 Note that the columnar phases observed for bolaamphiphiles are significantly different in structure to those formed by the more usual disk-shaped liquid crystal molecules.…”

“…Of particular interest are facial amphiphiles and bolaamphiphiles with laterally appended chains. 2,3 Bolaamphiphiles are rod-like molecules with a polar group at each end, thus a two-block molecule. The laterally attached alkyl chain(s) increase the number of immiscible groups to three.…”

Self‐assembly of compounds based on a glycerin skeleton as C‐3 building block. Part II

“…These molecules are called calamitic bolaamphiphiles. They evidenced no sign of formation of a smectic [smectic: a mesophase in which molecules arranged in layers with a well-defined spacing or periodicity (12)] layer structure but a rectangular columnar mesophase whose formation was explained by the microsegregation of the lateral polar chains from the rigid terphenyl cores into cylindrical domains with a locally enhanced concentration of the flexible polar polyether chains containing terminal glyceryl ether groups (3,13). In a general investigation of the self-organization of calamitic bolaamphiphiles, novel low molecular weight triblock molecules have been synthesized containing a rigid biphenyl core, polar 2,3-dihydroxypropoxy groups at each terminal end, and an additional long alkyl chain in a lateral position.…”

Fluorinated metallomesogens – lamellar versus columnar phase formation

“…It has been established that for some compounds even a minor changes within the mesogenic core can lead to major differences in molecular organization and therefore in liquid-crystalline behaviour. 4 There have been reported homologous series of compounds in which both types of phases, lamellar and columnar, occur upon changing the number and the position of substituents [5][6][7][8] or upon changing the length of peripheral alkyl chains. 9 Also, temperature can influence the type of molecular packing.…”