New complexes of liquid crystal discotic triphenylenes: induction of the double gyroid phase

Abstract

Electron donor-acceptor liquid crystals have been attracting considerable attention due to possible applications in optoelectronics and photonics. The creation of such charge transfer complexes is a powerful and flexible instrument...

Molecular mechanism of smectisation and regulation of polymorphism in nematic liquid crystal systems

“…Electron donor-acceptor LC have been attracting considerable attention due to possible applications in optoelectronics and photonics. The creation of such charge transfer complexes is a powerful and flexible instrument for modifying the structures and properties compared to those of the initial components [1][2][3]. In [4][5][6][7][8] the study of the molecular structure of nematic liquid crystal (NLC) systems that are based on polar liquid crystals, whose molecules have a large dipole moment directed along the long axis of the molecule (such as 4-n-buthyl-4 ′ -n ′ -heptanoiloxyazoxybenzene; n-cyanophenyl ester of n ′ -heptylbenzoic acid) as well as the investigation of a specific intermolecular interaction -the formation of charge transfer complexing (CTC) in LC systems were carried out by EPR, UV and IR spectroscopy.…”

Tunable Intermolecular Charge Transfer in Ionic Liquid Crystalline Derivatives of the [closo-B10H10]2– Anion

“…For these reasons, binary donor–acceptor (D–A) discotic LCs, − forming alternating columns, have been investigated as organic semiconductors, relatively efficient anisotropic charge conductors, , and laser addressable dichroics . These materials typically involve electron-rich π systems, such as derivatives of triphenylene, ,, hexabenzocoronene, , and truxene, and electron acceptors, for example, trinitrofluorenone, ,,,, naphthalenediimide, perylenediimide, , mellitictriimide, , and tetracyanoquinodimethane (TCNQ) . It has been demonstrated that the energy of the CT interactions in alternating D–A discotic LCs can be adjusted using a series of electron donors and acceptors. , While most effort in self-organizing materials exhibiting low-energy CT behavior has been dedicated to discotic LCs, other types of such LCs, e.g .…”

On a Specific Intermolecular Interactions in Nematic Liquid Crystal Systems

“…The intensity of this band increases with an increase in the {I} concentration in LC system. Using the expression [7] for the energy of charge−transfer band: (1) where − is the ionization potential of the donor, − is the acceptor electron affinity energy, − are other interactions, the short−wavelength band can be assumed to be absorption band for one of the complex types: . According to our semi empirical calculations [5] by atom−atom potential method two molecules in LC are arranged in such a way that the planes of the corresponding benzene rings become mutually parallel; for two molecules in pair the relative shift of the centers of the gravity of molecules along the long axis is 2−3 Å; with the exception of the oxygen atom of the carboxyl group of {I}, all the heteroatoms are in the planes of corresponding benzene rings and the dihedral angle between the planes of two benzene rings in each molecule is .…”