General phase-structure relationship in polar rod-shaped liquid crystals: Importance of shape anisotropy and dipolar strength

A new order of liquids: polar order in nematic liquid crystals

“…Li et al recently reported a significant number of new N F materials, many of which are homologous in structure with DIO with alternate polar functionalities and terminal chain lengths. 33 As a general trend, for a given core structure the shorter terminal chain lengths give the highest N F onset temperature, mirroring the behaviour of the earlier RM230-like materials. The 4-cyano-2′,3,5,6′-tetrafluorobiphenyl end group results in a remarkable increase in the onset temperature of the N F phase; the onset temperature of the propyl derivative is over 100 °C higher than that of DIO, with the methyl derivative being higher still.…”

“…28 Li et al recently reported a significant number of new N F materials, many of which are homologous in structure with DIO with alternate polar functionalities and terminal chain lengths. 33 As a general trend, for a given core structure the shorter terminal chain lengths give the highest N F onset temperature, mirroring the behaviour of the earlier RM230like materials. The 4-cyano-2 0 ,3,5,6 0 -tetrafluorobiphenyl end Fig.…”

“…5 Structural variants of DIO; transition temperatures (1C) are on cooling from the isotropic liquid. 28,[31][32][33] Green and red arrows indicate increased and decreased T NF-N relative to the parent material, respectively, while a black dash indicates the absence of the N F phase. 39 As with all N F materials known to date, these materials feature polar groups (in this case, 1,3-dioxane, 2,5difluorophenyl, nitrile) oriented in such a way to give a large longitudinal molecular electric dipole moment.…”

“…7 Structural variants of RM734-CN(2F); transition temperatures (1C) are on cooling from the isotropic liquid. 5,33 Green and red arrows indicate increased and decreased T NF-N relative to the parent material, respectively, while a black dash indicates the absence of the N F phase; note that the parent material does not display the N F phase.…”

Supermolecular Ferroelectric Nematic Materials

“…12 Progress in understanding and exploiting the unique physics of the NF phase is reliant on the design and synthesis of new materials, with significant progress in the since the report of the first polar nematic materials in 2017. 7,8,[13][14][15][16][17][18][19][20][21] The NF materials reported to date are exclusively rod-like, with polar groups (for example nitro, fluoro, cyano, esters, difluoromethoxy) oriented such that there is a large molecular electric dipole moment which is oriented close to parallel to the molecules long axis. Around 200 compounds have been reported in the literature as exhibiting the NF, 7,[13][14][15][16][18][19][20][21][22][23] and these are presently restricted to covalently bonded materials.…”