Synthesis and smectogenic properties of novel phloroglucinol-based star-shaped liquid crystals containing three peripheral alkyloxylated Schiff base arms

Ooi, Yew Hong; Yeap, Guan‐Yeow; Han, Chun Chieh; Lin, Hong‐Cheu; Kenji, Kubo; Ito, Masato

doi:10.1080/02678292.2012.761734

Cited by 25 publications

(4 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phloroglucinol is a readily available commercial trifunctional core which has been used to develop an array of C 3 -symmetric compounds. − A triped monomer core was designed by coupling phloroglucinol with 1,5-dibromopentane or 1,10-dibromodecane as shown in Scheme . An excess (4.5 equiv) of the α,ω-dibromoalkane was used in the coupling to drive the reaction to completion.…”

Section: Results and Discussionmentioning

confidence: 99%

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Nardele

Asha

2014

J. Phys. Chem. B

View full text Add to dashboard Cite

Liquid crystalline azobenzene containing triped and tetraped monomers were designed and synthesized and further used as B3 and B4 type monomers to form hyperbranched polymers with tetraethylene glycol as the A2 type comonomer. The mesophase characteristics of the multiarm-star mesogens and hyperbranched polymers were analyzed using various instrumentation techniques like differential scanning calorimetry (DSC), polarized light microscopy (PLM) and variable temperature XRD. The multipod monomers as well as hyperbranched polymers exhibited thermotropic smectic liquid crystalline characteristics with a tendency toward higher ordered smectic LC phases with increased branching. The hyperbranched polymers exhibited lamellar organization even in the as-solvent precipitated powder sample indicating higher extent of nanosegregation. Their potential application as fast switching photochromic materials was highlighted by carrying out isothermal photoswitching experiments in the LC state. Reversible isothermal smectic-isotropic phase transition could be achieved by UV irradiation in <1 s in the multipod monomers, while it required >2 s UV irradiation in the case of the hyperbranched polymers.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Nardele

Asha

2014

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…[16][17][18] Consequently, trimesic acid or phloroglucinol found utility as a structural motif for realizing a wide range of star-like molecular architectures that show simple nematic mesophases as well as lamellar and columnar mesophases. [19][20][21][22][23][24][25][26][27][28] Fundamentally, from the perspective of molecular design, by changing the linking pattern of the phenyl ring (extensively used building block), numerous molecular mesogens can be realized. [29,30] The gross molecular shape or the conformation of such non-conventional mesogens in the liquid crystalline phase can lead to the supramolecular organization, paving the way for complex morphologies unheard of conventional mesogenic molecules.…”

Section: Introductionmentioning

confidence: 99%

Molecular Conformations of Shape Anisometrically Variant Mesogens in Liquid Crystalline Phase Studied by ¹³C NMR Spectroscopy

Veeraprakash,

Shanavas,

Reddy

et al. 2023

ChemPhysChem

View full text Add to dashboard Cite

Mesogens that vary in shape anisometry have been investigated by 13C solid‐state NMR in the liquid crystalline phase to inspect the conformations. The molecules examined comprise of (i) rod‐like mesogen with three‐phenyl ring core and terminal hexyloxy chains, (ii) three‐ring core linked to the fourth phenyl ring via a spacer, and (iii) trimesic acid connected to three side arms core units through a spacer. The order parameter (Szz) values for the phenyl rings of the rod‐like mesogen are 0.65‐0.68, while the mesogen with a three‐ring core linked to a phenyl ring via spacer showed dissimilarity. Consequently, for the core unit's phenyl rings, Szz is ~ 0.70, and the terminal phenyl ring showed a low value of 0.12. For the trimesic acid based mesogen, the Szz value for the side arm phenyl rings is ~ 0.53, and for the central phenyl ring, a very low value of 0.11 is witnessed. By considering the ordering of the rod‐like mesogen as a yardstick and employing the ratios of Szz values of the phenyl rings, the average conformations of other mesogens are arrived. Accordingly, for the trimesic acid based mesogen, a tripod‐like conformation instead of l shape is proposed in the liquid crystalline phase.

show abstract

“…Furthermore, the azomethine/ester homologues have recently instructed the identification of twist-bend smectic phases [11,12]. The mesophase behavior of non-symmetrical biphenyl derivatives [13,14] has been recently explored. Moreover, the addition of a new connecting group and a change to the rigid component stabilized the mesomorphic behavior and may have resulted in the development of new phases [15,16].…”

Section: Introductionmentioning

confidence: 99%

Wide Nematogenic Azomethine/Ester Liquid Crystals Based on New Biphenyl Derivatives: Mesomorphic and Computational Studies

et al. 2022

View full text Add to dashboard Cite

The thermal stability and mesomorphic behavior of a new biphenyl azomethine liquid crystal homologues series, (E)-4-(([1,1’-biphenyl]-4-ylmethylene)amino)phenyl 4-(alkoxy)benzoate, In, were investigated. The chemical structures of the synthesized compounds were characterized using FT-IR, NMR, and elemental analyses. Differential scanning calorimetry (DSC) and polarized optical microscopy were employed to evaluate the mesomorphic characteristics of the designed homologues. The examined homologues possessed high thermal stability and broad nematogenic temperature ranges. Furthermore, the homologues were covered by enantiotropic nematic phases. The experimental measurements of the mesomorphic behavior were substantiated by computational studies using the density functional theory (DFT) approach. The reactivity parameters, dipole moments, and polarizability of the studied molecules are discussed. The theoretical calculations demonstrated that as the chain length increased, the polarizability of the studied series increased; while it did not significantly affect the HOMO–LUMO energy gap and other reactivity descriptors, the biphenyl moiety had an essential impact on the stability of the possible geometries and their thermal as well as physical parameters.

show abstract

Synthesis and smectogenic properties of novel phloroglucinol-based star-shaped liquid crystals containing three peripheral alkyloxylated Schiff base arms

Cited by 25 publications

References 47 publications

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Molecular Conformations of Shape Anisometrically Variant Mesogens in Liquid Crystalline Phase Studied by ¹³C NMR Spectroscopy

Wide Nematogenic Azomethine/Ester Liquid Crystals Based on New Biphenyl Derivatives: Mesomorphic and Computational Studies

Contact Info

Product

Resources

About

Synthesis and smectogenic properties of novel phloroglucinol-based star-shaped liquid crystals containing three peripheral alkyloxylated Schiff base arms

Cited by 25 publications

References 47 publications

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Photoresponsive Smectic Liquid Crystalline Multipods and Hyperbranched Azo Polymers

Molecular Conformations of Shape Anisometrically Variant Mesogens in Liquid Crystalline Phase Studied by 13C NMR Spectroscopy

Wide Nematogenic Azomethine/Ester Liquid Crystals Based on New Biphenyl Derivatives: Mesomorphic and Computational Studies

Contact Info

Product

Resources

About

Molecular Conformations of Shape Anisometrically Variant Mesogens in Liquid Crystalline Phase Studied by ¹³C NMR Spectroscopy