Y-shaped tricatenar azobenzenes – functional liquid crystals with synclinic–anticlinic transitions and spontaneous helix formation

Lyotropic liquid crystals are fluids with macroscopic anisotropic structures formed by the self-assembly of nonspherically-symmetric mesogenic molecules or nanoparticles. Here, lyotropic liquid crystalline phases with discotic-nematic orderings were observed in colloidal dispersions of hexagonal-shaped nanoplatelets of two-dimensional layered hybrid organic-inorganic metal halide perovskites (with formula A2BX4 where A1+ is an organic ammonium cation, B2+ is a divalent metal cation, and X1- is a halide anion) synthesized via microcrystallization by mixing precursor solutions with antisolvents containing surfactants, which showed semiconducting properties such as blue to green photoluminescence. As nanocrystalline perovskites are compositionally (transition metals like manganese, copper or europium as octahedral unit centers, mixed halides, organic spacers with chirality, etc.), microscopic structurally (three-, two-, or one-dimensional), and geometrically (nanosheets or nanorods) adjustable, liquid crystals with different phase behaviors and physical features (e.g., paramagnetism) may be systematically developed using this method.

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Helical Networks of π‐Conjugated Rods – A Robust Design Concept for Bicontinuous Cubic Liquid Crystalline Phases with Achiral Ia 3¯ d and Chiral I 23 Lattice

Advanced Functional Materials ◽

10.1002/adfm.202004353 ◽

2020 ◽

Vol 30 (45) ◽

pp. 2004353 ◽

Cited By ~ 2

Author(s):

Christian Dressel ◽

Tino Reppe ◽

Silvio Poppe ◽

Marko Prehm ◽

Huanjun Lu ◽

...

Keyword(s):

Robust Design ◽

Liquid Crystalline ◽

Design Concept ◽

Crystalline Phases ◽

Liquid Crystalline Phases ◽

Bicontinuous Cubic

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Order and dynamics of rod-like and banana-shaped liquid crystals by 2H NMR

Pure and Applied Chemistry ◽

10.1351/pac200779010021 ◽

2007 ◽

Vol 79 (1) ◽

pp. 21-37 ◽

Cited By ~ 27

Author(s):

Valentina Domenici

Keyword(s):

Molecular Dynamics ◽

Liquid Crystals ◽

Liquid Crystalline ◽

Dynamic Properties ◽

Orientational Order ◽

Chemical Properties ◽

Soft Materials ◽

Point Of View ◽

Crystalline Phases ◽

Liquid Crystalline Phases

Deuterium NMR spectroscopy is a very powerful technique for studying partially or totally ordered systems, such as liquid crystals (LCs) and polymers. LCs represent a branch of the most general class of soft materials, with peculiar physical and chemical properties which attracted scientific attention for their potentiality for technological applications. From a chemical point of view, there are three aspects in which 2H NMR could provide significant insights: (i) the conformational and structural properties; (ii) the molecular dynamics and mobility; and (iii) the orientational order and aggregation/distribution of molecules in the different liquid-crystalline phases. In this work, some of the recent developments in this field are discussed, focusing on two main topics: (1) the molecular dynamics of the smectic liquid-crystalline phases formed by rod-like molecules and (2) the unusual orientational and dynamic properties of the new liquid-crystalline mesophases formed by banana-shaped molecules (BLCs).

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Colloidal Lyotropic Liquid Crystalline Phases of Two-Dimensional Nanoparticles of Layered Hybrid Organic-Inorganic Metal Halide Perovskites

10.26434/chemrxiv.13692448 ◽

2021 ◽

Author(s):

PEI-XI WANG

Keyword(s):

Liquid Crystals ◽

Self Assembly ◽

Liquid Crystalline ◽

Metal Halide ◽

Lyotropic Liquid Crystals ◽

Two Dimensional ◽

Halide Anion ◽

Crystalline Phases ◽

Liquid Crystalline Phases ◽

Halide Perovskites

Lyotropic liquid crystals are fluids with macroscopic anisotropic structures formed by the self-assembly of nonspherically-symmetric mesogenic molecules or nanoparticles. Here, lyotropic liquid crystalline phases with discotic-nematic orderings were observed in colloidal dispersions of hexagonal-shaped nanoplatelets of two-dimensional layered hybrid organic-inorganic metal halide perovskites (with formula A2BX4 where A1+ is an organic ammonium cation, B2+ is a divalent metal cation, and X1- is a halide anion) synthesized via microcrystallization by mixing precursor solutions with antisolvents containing surfactants, which showed semiconducting properties such as blue to green photoluminescence. As nanocrystalline perovskites are compositionally (transition metals like manganese, copper or europium as octahedral unit centers, mixed halides, organic spacers with chirality, etc.), microscopic structurally (three-, two-, or one-dimensional), and geometrically (nanosheets or nanorods) adjustable, liquid crystals with different phase behaviors and physical features (e.g., paramagnetism) may be systematically developed using this method.

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