163628-91-9Relevant articles and documents
Triphenylene discotic liquid crystal trimers synthesized by Co 2(CO)8-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition
Han, Bin,Hu, Ping,Wang, Bi-Qin,Redshaw, Carl,Zhao, Ke-Qing
, p. 2852 - 2861 (2013)
The synthesis of star-shaped discotic liquid crystal trimers using Co 2(CO)8-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition reaction is reported. The trimers consist of three triphenylene discotic units linked to a central 1,2,4-trisubstituted benzene ring via flexible spacers. The trimers were synthesized in the yields up to 70% by mixing the monomers with 10 mol % of Co2(CO)8 as the catalyst in refluxing 1,4-dioxane. The liquid crystalline properties were investigated by using polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Trimer 4 with an ester connecting group and a longer spacer 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.
New complexes of liquid crystal discotic triphenylenes: Induction of the double gyroid phase
Bondarenko, G. N.,Ivanov, D. A.,Maryasevskaya, A. V.,Merekalov, A. S.,Otmakhova, O. A.,Piryazev, A. A.,Shandryuk, G. A.,Talroze, R. V.
, p. 16827 - 16836 (2021/08/20)
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 for modifying the structures and properties compared to those of the initial components. In the present work, such an approach is exemplified on new complexes formed via non-covalent interactions of triphenylene discotics, namely, 2,3,6,7,10,11-hexakis(pentyloxy) triphenylene (H5T) and 2-(acryloyloxypropyloxy)-3,6,7,10,11-pentapentylox-triphenylene (TPh-3A), with an electron acceptor, β-(2,4,7-trinitro-9-fluorenylideneaminooxy) propionic acid (TNF-carb). The structure of thin supported films of H5T, TPh-3A and their blends with TNF-carb was investigated by grazing-incidence wide-angle X-ray scattering using a synchrotron source. At room temperature, the pristine discotics crystallize in orthorhombic unit cells whereas the self-assembly of H5T and TPh-3A with TNF-carb results in a double gyroid and hexagonal phases, respectively. Formation of the double gyroid phase with the lattice parameter of 36.5 ? is driven by phase separation between the aromatic and alkyl regions of the system. It is supposed that the TNF-carb molecules of the complex are positioned in the nodes of the structure while the H5T molecules are located in the struts adjoining the nodes via triple junctions. For the hexagonal crystal of the TPh-3A/TNF-carb complex, the acceptor molecules are likely located in the interstices between the neighboring supramolecular columns of TPh-3A. The molecular structures of the blends were also explored by means of FTIR spectroscopy. A detailed FTIR spectra analysis illustrates fine changes in inter-molecular bonds. For example, the initially dimerized acceptor molecules totally disappear in the complex structures whereas in TPh-3A/TNF-carb additional H-bonds between the carboxylate group in TNF-carb and the ester group of TPh-3A form. The experimental data allows putting forward possible molecular models of the complex structures. This journal is
A convenient and economic method for the synthesis of monohydroxy- pentaalkoxy- and hexaalkoxytriphenylene discotics
Kumar, Sandeep,Lakshmi
, p. 2603 - 2605 (2007/10/03)
A one-step process for the preparation of mono-functionalized triphenylene discotics is presented. Oxidative trimerization of ortho-dialkoxybenzenes using FeCl3 in nitromethane and a catalytic amount of various acids, furnished monohydroxy-pentaalkoxytriphenylene in addition to hexaalkoxytriphenylene. These products can be easily separated by column chromatography over aluminium oxide.
