C₃ Symmetric Hexaphenyltriphenylenehexamide: Molecular Design of Fluorescent Ferroelectrics

Abstract

Organic materials with diverse molecular designs and assemblies may exhibit new multifunctional properties such as coupled ferroelectric, optical, and transport properties. Herein, we propose design guidelines for multifunctional organic ferroelectric materials based on areneoligoxamide. The key points are the careful selection of a disk‐shaped central π scaffold and the symmetric introduction of terminal alkyl amide groups with high motility. The effectiveness of these guidelines are demonstrated through the synthesis of C3 symmetric hexaphenyltriphenylenehexamide (6TP), which showed a significant polarization‐electric field hysteresis in the liquid crystalline (LC) state with fluorescent properties. Spacing between the ortho‐diamide with a phenylene spacer not only expanded the molecular design for ferroelectric LC but also increased the thermal stability of areneoligoxamide.

Nanoscale Effects in One‐Dimensional Columnar Supramolecular Ferroelectrics

“…On the contrary, practically all applicable inorganic ferroelectrics have several problems to overcome, such as toxicity, heavy weight, rare metal utilization, device fabrication cost, and others. The development of organic ferroelectrics is one of the potential approaches that might solve the above problems simultaneously, and a variety of organic materials have been developed in the areas of charge transfer, hydrogen bonding, simple cation‐anion exchange, and organic–inorganic hybrid crystals . A higher degree of design freedom for organic materials than that for the inorganic ones can allow facile expansion of the variety of materials and also mechanisms with which the order–disorder polarization inversion, such as proton transfer and supramolecular rotator, stores bits …”

“…The development of organic ferroelectrics is one of the potential approaches that might solve the above problems simultaneously,a nd av ariety of organic materials have been developed in the areas of charget ransfer,h ydrogen bonding, simple cation-anion exchange, and organic-inorganic hybrid crystals. [4][5][6][7][8][9][10] Ah igher degree of design freedom for organic materials than that for the inorganic ones can allow facile expansion of the varietyo fm aterials and also mechanisms with which the order-disorder polarizationi nversion,s uch as proton transfer and supramolecular rotator, stores bits. [11,12] Both the remanentp olarization (P r )a nd the coercive electric field (E c )a re important as the typicalf erroelectric parameters, which are associated with the ON/OFF ratio of as witching event,a nd an applied voltage in the memory device, respectively.F or instance, both the P r = 21 mCcm À2 and the E c = 29 kV cm À1 values of single-crystal croconic acid is superior to that of the P r = 15 mCcm À2 and E c = 85 kV cm À1 values for PZT.…”

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

“…[1][2][3][4] Many studies show that these liquid crystals (LC) display interesting physical and chemical properties making them suitable candidates for several applications such as electrophotography, 5 electronics and optoelectronics, 6 LEDs, 7 or chemical sensing. 8 They have been also studied as materials for surface modification, 9 as stabilizers of nanoparticles, 10,11 as fluorescent ferroelectric materials, 12 and even for birefringent films that improve the viewing angle of liquid crystal displays. 13 There are many reports where electron-withdrawing or donating side groups are covalently bonded directly to the triphenylene core: nitro and amino groups, [14][15][16][17] cyano group, 18 halides, 19,20 alkyl/alkoxy fragments, 21,22 or organometallic moieties.…”

Ferroelectricity of a Tetraphenylporphyrin Derivative Bearing −CONHC14H29 Chains at 500 K

“…46 Recently, we also designed an extended π-system of hexaphenyltriphenylene and non-π-planar helicene derivatives bearing multiple −CONHC 14 H 29 chains to design new organic ferroelectrics. 47,48 The latter racemic helicene derivative bearing two −CONHC 14 H 29 chains showed an excellent ferroelectric parameter of P r = 11.1 μC cm −2 and E c = 20 V μm −1 because of the formation of a 2D lamellar (L a ) liquid crystalline phase with a considerably high density of hydrogenbonding sites. 48 The chemical design of the central π core is among the essential factors to show the liquid crystalline property, ferroelectricity, and multifunctionality of the supra-molecular assemblies.…”

“…Therefore, we designed a highly emissive pyrene derivative ( 4PC ) bearing four −CONHC 14 H 29 chains that showed a blue-green fluorescence conversion because of monomer–excimer formation, fluorescent organogels, nanofibers, and a Col h liquid crystal phase as well as ferroelectricity and current-switching behavior according to the ferroelectric local electric field . Recently, we also designed an extended π-system of hexaphenyltriphenylene and non-π-planar helicene derivatives bearing multiple −CONHC 14 H 29 chains to design new organic ferroelectrics. , The latter racemic helicene derivative bearing two −CONHC 14 H 29 chains showed an excellent ferroelectric parameter of P r = 11.1 μC cm –2 and E c = 20 V μm –1 because of the formation of a 2D lamellar (L a ) liquid crystalline phase with a considerably high density of hydrogen-bonding sites . The chemical design of the central π core is among the essential factors to show the liquid crystalline property, ferroelectricity, and multifunctionality of the supramolecular assemblies.…”