Highly Resolved Morphology of Room‐Temperature Columnar Liquid Crystals Derived from Triphenylene and Multialkynylbenzene Using Reconstructed Electron Density Maps

Abstract

This paper demonstrates highly resolved structure of the self‐assembly of dyad and triads constituted from triphenylene (T) and multialkynylbenzene (M) units linked via flexible alkyl spacers (n). Resolved structures of these systems are based on reconstructed electron density maps derived from X‐ray diffraction patterns. T‐M compound (dyad) exhibits columnar hexagonal (Colh) phase which is explained by its columnar layered structure. In contrast, T‐M‐T compounds (triads) with spacer lengths of n = 8 and 10 exhibited columnar oblique (Colob) mesophase whereas, the one with shortest spacer length, i. e., n = 6, showed a columnar oblique plastic (Colobp) phase. We also found that molecules are interdigitated within themselves for compounds having longer spacer lengths (n = 8 and 10). However, a side by side packing is observed for the compound with shortest alkyl spacer (n = 6).

Observation of helical self-assembly in cyclic triphosphazene-based columnar liquid crystals bearing chiral mesogenic units

“…To figure out the arrangement of these mesogens on the various 2D lattices, the electron density maps 46 were constructed using the information derived from the peak, index, and intensity data of the XRD pattern, and the 2D projection model (Fig. 5d–f) of all the columnar arrangements was also displayed.…”

Electroluminescent Aggregation-Induced Emission-Active Discotic Liquid Crystals Based on Alkoxy Cyanostilbene-Functionalized Benzenetricarboxamide with Ambipolar Charge Transport

“…In addition, to gain a better knowledge of the molecular arrangement in the hexagonal phase, EDMs were reconstructed using the information of the peak indexes and intensities (Figures a and S24). ,− The EDM for compound 1a is shown in Figure a. EDM indicates that higher electron density regions exhibit a honeycomb structure (Figure a), and the low electron density region forms a regular hexagonal lattice.…”

“…The XRD patterns of compounds 1a−c (Figure 2b,d,f) in the mesophase temperature range exhibit three peaks in a small-angle region with a d-spacing ratio of 1/1:1/√4:1/√7 corresponding to reflection from the planes ( 10), (20), and (21) of the hexagonal lattice. Moreover, the appearance of one broad peak, h a , in the wide-angle region of spacing 4.96−4.99 Å, is due to a flexible alkyl chain−chain correlation and a broad hump h c for 1a and 1b, with a spacing of 3.65 Å, suggesting π−π interactions.…”

“…The electron density maps (EDMs) were reconstructed using a previously reported procedure, ,− where generally the EDMs of all potential phase combinations are created. The “right” map is then picked based on the merits of the rebuilt maps as well as other physical and chemical information about the system, such as chemical constituents and their sizes.…”

Striking Increase in Hole Mobility upon Metal Coordination to Triphenylene Schiff Base Semiconducting Multicolumnar Mesophases

“…There have also been reports where the triphenylene is functionalized at the end of one of the alkoxy substituents, so that the triphenylene core and the functional group are far apart and are electronically disconnected. This case can favor the formation of mesophases with segregated columns of different natures − and interesting mesophases with ambipolar charge transport properties − or with efficient photocurrent generation. , …”