Different disk structures in the hexagonal columnar mesophases of 2,3‐dicyano‐6,7,10,11‐tetraalkoxy‐1,4‐diazatriphenylenes and 2,3‐dicyano‐6,7,10,11‐tetraalkoxytriphenylenes

Synergistic π–π and Pt–Pt interactions in luminescent hybrid inorganic/organic dual columnar liquid crystals

“…There is no reason to think that the stacked distance between triphenylene groups in our complexes should be very different from that found in many structures of organic systems with stacked triphenylene groups, which are found in the range 3.43-3.66 Å (average 3.54 Å). 49 Assuming this value, this corresponds to a h value about 7 Å for the repeat unit containing two triphenylenes).…”

Synthesis of Substituted Dibenz[a,c]anthracenes and an Investigation of Their Liquid‐Crystalline Properties

“…The columnar mesophase temperature range of series 14 reported by Ichihara et al [26] exhibits crystalline to columnar melting transition-phase transitions that are strikingly similar to those of compounds 6a-c. In contrast, the clearing points for compounds 14 are approximately 187-190°C, whereas the corresponding dibenzanthracene series 6a-c shows clearing points ranging from approximately 219°C to 225°C.…”

“…A comparison of compounds 6a-c with the corresponding tetraalkoxydicyanotriphenylenes (14) reported by Ichihara et al [26] allows us to assess the effect of extending the aromatic core by one fused benzene ring upon mesophase stability. Several studies have suggested that increasing the size of the PAH core promotes stable mesophases.…”

“…[20,26] For the series of dicyanotriphenylenes 14, Ohta and co-workers have attributed the lack of clearing point changes to the formation of a dimeric disk assembly (vide supra), suggesting that the clearing point is determined by dimer dissociation. This behavior is atypical for columnar liquid-crystalline materials, which usually show a decrease in the clearing point with longer alkyl chains.…”

Generation of liquid crystallinity from a Td-symmetry central unit

“…15 Most of the core structures that form DLCs are Cn-symmetry planar molecules, such as benzene, pyridine, triazine, triphenylene, diazatriphenylene, hexaazatriphenylene, dibenzonapthacene, pyrene, tristriazolotriazine, rufigallol, etc. 2,[16][17][18][19][20] Adamantane molecule has a rigid tetrahedral Td-symmetry which is made up of four cyclohexane rings fused in chair conformation. It has two equivalent sites, the bridge and bridgehead positions, its polycyclic cage is similar to that of the unit cell of diamond crystal lattice with an almost identical carbon-carbon bond length corresponding to 1.54Å.…”