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An extensive study on the effect of terminal halogens on the structure–property relationship of polar L-shaped mesogens has been elucidated.

A new approach accompanied by superstructural frustration is reported. By attaching a cholesterol moiety directly to the central bent-core system it displayed exotic BPIII, BPII/I, Ncyb*, TGBA, SmAPA, SmA and SmX phases as shown by X-ray scattering results. While higher homologues of the series exhibited spontaneous formation of polar order (Ps ∼ 61 nC cm-2) upon applied voltage, the lower homologues showed thermochromic behaviour which can also be trapped via temperature quenching.

Three-ring based BLCs exhibiting orthogonal smectic and nematic phases with antiparallel arrangement as derived from SCXRD and X-ray scattering results.

Table of contents: 1. Synthesis and Characterization 2. UV-Vis and fluorescence spectra 3. X-ray diffraction and molecular arrangement 4. DFT study 5. Materials and reagents

We report the synthesis and characterization of a new class of achiral three-ring bent-core compounds with an amide and ester linkage at the molecular bend, which are shown to exhibit nematic/phases in wide temperature ranges around room temperature (RT) and undulated SmC phases below RT. In contrast to previous studies, the compounds reported in this Communication show a true RT nematic phase with fluid physical appearance. They show strong photoluminescence in the mesophase and are found to display a one-dimensional array of intermolecular hydrogen bonding. Furthermore, the nematic phases exhibited by these compounds show a good homeotropic alignment that can be exploited in applications such as optics and sensing. Considering the scarcity of bent-core materials exhibiting an RT nematic mesophase, this new class of materials is promising.

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Recently,a nu nprecedented observation of polar order,t hermochromic behavior,a nd exotic mesophases in new chiral, bent-shapeds ystemsw ith a ÀCH 3 moiety placed at the transverse position of the central core was reported. Herein,ah omologous series of compounds with even-numbered carbonc hains from n = 4t o1 8w ere synthesized, in which ÀCl was substituted for ÀCH 3 at the kink position and ad rastic modification in the phase structure of the bentshaped moleculew as observed. An unusuals tabilization of the cubic blue phase (BP) over aw ide range of 16.4 8Ch as been witnessed. Twoh omologues in this series (1-12 and 1-14) exhibit an interesting phase sequence consisting of BPI/ II, chiraln ematic, twist grain boundary,s mectic A, and smectic X( SmX) phases.T he higher homologues( 1-16 and 1-18) stabilizet he SmX phase enantiotropically over the entire temperature range. Crystal structure analysis confirmed the bent molecular architecture, with ab ent angle of 1488,a nd revealed the presenceo ft wo different molecular conformations in an asymmetric unit of compound 1-4. AD FT study corroborated that the ÀCl moiety at the central core of the molecule led to an increasei nt he dipole momenta long the transverse direction, which, in turn, facilitated the unusual stabilization of frustrated structures.C rystal polymorphism has been evidenced in three homologues( 1-10, 1-12, and 1-14) of the series. On the application of mechanical pressure through grinding, compound 1-10 transformedf rom a brighty ellow crystalline solid to ad ark orange-green amorphouss olid, which reversed upon dropwise additiono fd ichloromethane, indicating reversible mechanochromism in this class of compounds. In addition,e xcellent thermochromic behavior has been observed for compound 1-10w ith a controlled temperature-colorcombination.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.[a] Cr = crystal;I so = isotropic;N cyb * = chiral nematic phase composed of Sm clusters;T GBA = twist grain boundary phase;S mectic A = SmA; Smectic X = SmX. [b] Phaset ransitionso bserved by meanso fP OM in an ITO-coated planar cell (antiparallelrubbing). [c] Phase transitionso bserved by means of SAXS/WAXS.( 1-14: Cr 1a = amorphous,C r 2b = transition crystalline state, Cr 3c = crystal polymorph.)Chem.E ur.