scholarly journals Improving the mesomorphic behaviour of supramolecular liquid crystals by resonance-assisted hydrogen bonding

2019 ◽  
Vol 7 (28) ◽  
pp. 8643-8648 ◽  
Author(s):  
Marco Saccone ◽  
Michael Pfletscher ◽  
Sven Kather ◽  
Christoph Wölper ◽  
Constantin Daniliuc ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Hydrogen Bonded

A significant impact of resonance-assisted hydrogen-bonding (RAHB) on the liquid crystalline behavior of hydrogen-bonded mesogens is reported and systematically investigated.

Experimental and computational (DFT) studies on induced orthogonal smectic A∗ phase in hydrogen-bonded ferroelectric liquid crystals

2018 ◽  
Vol 32 (21) ◽  
pp. 1850223 ◽  
Author(s):  
P. Subhasri ◽  
R. Jayaprakasam ◽  
V. N. Vijayakumar
Keyword(s):  
Liquid Crystals ◽  
Molecular Orbital ◽  
Density Functional ◽  
Liquid Crystalline ◽  
Proton Acceptor ◽  
Dft Studies ◽  
Ferroelectric Liquid Crystals ◽  
Smectic A ◽  
Present Complex ◽  
Hydrogen Bonded

Hydrogen-bonded ferroelectric liquid crystals (HBFLC) are designed and synthesized from nonmesogenic chiral proton donor compound of (R)-([Formula: see text])-Methylsuccinic acid (MSA) and mesogenic proton acceptor compound of 4-undecyloxybenzoic acid (11OBA) in a different mole ratio. Intermolecular hydrogen bonds (H-bond) between the nonmesogenic and mesogenic compounds have been confirmed through experimental Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) computational studies. The steric hindrance and inductive effects of the present complex and its influence on the structure are discussed. A rich phase polymorphism in the liquid crystalline complex has been studied using polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The chiral phases observed in the present complex are due to the presence of lone pair (n) to anti-bonding ([Formula: see text]) transition symmetry which is validated by DFT studies. A noteworthy observation of induced smectic A[Formula: see text](Sm A[Formula: see text]) by quenching of traditional phase (nematic) has been identified and the reason for the same has been discussed by DFT studies. The unusual phase order of Sm A[Formula: see text], smectic C[Formula: see text](Sm C[Formula: see text]) and smectic G[Formula: see text][Formula: see text](Sm G[Formula: see text]) mesogenic phases are observed. The other liquid crystalline parameters are evaluated by experimental and theoretical calculations and the same has been compared. Increased tilt angle in liquid crystal (LC) molecules has been theoretically analyzed by natural bond orbital (NBO) studies. Stability of the HBFLC phases and its origination mechanism have been discussed with the help of highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO–LUMO) energies.

scholarly journals Tuning the photonic properties of chiral nematic mesoporous organosilica with hydrogen-bonded liquid-crystalline assemblies

2015 ◽  
Vol 3 (7) ◽  
pp. 1537-1545 ◽  
Author(s):  
Michael Giese ◽  
Tim Krappitz ◽  
Ronald Y. Dong ◽  
Carl A. Michal ◽  
Wadood Y. Hamad ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Optical Microscopy ◽  
Liquid Crystalline ◽  
Cd Spectroscopy ◽  
Polarized Optical Microscopy ◽  
Mesoporous Organosilica ◽  
Chiral Nematic ◽  
Hydrogen Bonded

The thermochromic behaviour of chiral nematic mesoporous organosilica hybrids infiltrated with hydrogen-bonded liquid crystals was investigated by polarized optical microscopy, UV-vis and CD-spectroscopy.

Sub-5 nm structured films by hydrogen bonded siloxane liquid crystals and block copolymers

2018 ◽  
Vol 6 (12) ◽  
pp. 3042-3046 ◽  
Author(s):  
Koen Nickmans ◽  
Rob C. P. Verpaalen ◽  
Jeffrey N. Murphy ◽  
Albert P. H. J. Schenning
Keyword(s):  
Thin Films ◽  
Hydrogen Bonding ◽  
Liquid Crystals ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Inorganic Thin Films ◽  
Hydrogen Bonded

Polymeric supramolecules were prepared using hydrogen-bonding oligo(dimethylsiloxane)-based liquid crystals and poly(4-vinylpyridine) homopolymer or poly(styrene)-b-poly(4-vinylpyridine) block copolymer. These materials form glassy, hybrid organic/inorganic thin films with sub-5 nm features.

scholarly journals ortho-Fluorination of azophenols increases the mesophase stability of photoresponsive hydrogen-bonded liquid crystals

2018 ◽  
Vol 6 (37) ◽  
pp. 9958-9963 ◽  
Author(s):  
Marco Saccone ◽  
Kim Kuntze ◽  
Zafar Ahmed ◽  
Antti Siiskonen ◽  
Michael Giese ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Enhanced Stability ◽  
Hydrogen Bonded

We present a photoresponsive supramolecular liquid-crystalline (LC) system with enhanced stability of the LC phase due to ortho-fluorination of the bond-donating hydroxyazobenzene derivative, an important characteristic for their future use in photonics.

Hierarchically ordered nanostructures of a supramolecular rod-coil block copolymer with a hydrogen-bonded discotic mesogen

2019 ◽  
Vol 10 (8) ◽  
pp. 991-999 ◽  
Author(s):  
Hongbing Pan ◽  
Wei Zhang ◽  
Anqi Xiao ◽  
Xiaolin Lyu ◽  
Pingping Hou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Liquid Crystalline ◽  
Hierarchical Structures ◽  
Molar Ratio ◽  
Ordered Nanostructures ◽  
Hydrogen Bonded

Supramolecular liquid crystalline block copolymers prepared via hydrogen bonding exhibit hierarchical structures that can be tuned by varying the molar ratio of the discotic hydrogen-bonding acceptor to the block copolymer donor.

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