Comparing X-ray studies of smectic A phases formed by laterally branched molecules

Diele, Siegmar; Mädicke, A.; Knauft, K.; Neutzler, J.; Weißflog, W.; Demus, D.

doi:10.1080/02678299108028228

Cited by 36 publications

(9 citation statements)

References 10 publications

(4 reference statements)

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“…Baumeister, et al (1990) synthesized a compound 4-ethoxy-2′-(4-ethoxyphenyliminomethyl)-4'-(4-methoxybenzoyloxy) azobenzene with the observation of the nematic (N) phase. Same feature was observed in the study done by Diele, et al, 1991, where the N and S m A phases were been observed. Berdague, et al (1993) reported new laterally aromatic branched liquid crystal (LC) materials with the N and S m C phases.…”

Section: Introductionsupporting

confidence: 67%

Synthesis and Liquid Crystalline Studies of 2,4-bis(4'-n-nonyloxybenzoyloxy)benzylidene-4''-n-alkoxyaniline

Hamad

Salih

2017

ARO

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Abstract-In this paper, a series of new Schiff-bases: 2,4-bis (4'-n-nonyloxy -benzoyloxy)benzylidene-4''-n-alkyloxyaniline (DC 9 A n ) were synthesized. The characterization of compounds was achieved through using (ultra violet, infrared, 1 H-nuclear magnetic resonance) measurements. This series comprises 10 members differ by the length of n-alkoxy chain (i.e., OC n H 2n+1 , n=1-10). Their liquid crystalline properties were studied using differential scanning calorimetry and polarizing optical microscopy. The lower series such as n=1-3 are purely nematogenic liquid crystals, but the other means (n=4-7) have nematic and smectic phases (S m C and S m A). The higher members (n=8-10) are purely smectogenic liquid crystals.

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Section: Introductionsupporting

confidence: 67%

Synthesis and Liquid Crystalline Studies of 2,4-bis(4'-n-nonyloxybenzoyloxy)benzylidene-4''-n-alkoxyaniline

Hamad

Salih

2017

ARO

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“…Gray [21] has proposed that this rarity is associated with intermolecular hydrogen bonding raising the melting point above the mesophase-isotropic liquid transition temperature, and perhaps also encouraging a nonlinear molecular arrangement that is incompatible with mesophase formation. After an initial investigation by Weissflog and Demus [22], a number of homologues series with a trisubstituted benzene nucleus have been reported [23][24][25][26][27][28][29][30]. Schroeder and Schroeder [31] reported a few terminally hydroxy substituted mesogens.…”

Section: Introductionmentioning

confidence: 99%

Substitution Effects on the Liquid Crystalline Properties of Thermotropic Liquid Crystals Containing Schiff Base Chalcone Linkages

Thaker

Patel

Vansadiya

et al. 2009

Molecular Crystals and Liquid Crystals

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“…This parallel arrangement seems to be connected with the sterically induced destabilization of the mesophase found by Jacobi et al 13) For our samples, the more stable phases are connected with a perpendicular arrangement; a parallel structure means a destabilization! Additionally, the wedge-like shape of these mesogens 22) must be taken into account for further discussions.…”

Section: Discussionmentioning

confidence: 99%

Mutual orientation of main chains and side chains in nematic liquid-crystalline side-chain polysiloxanes

Hempel¹,

Jacobi

Weißflog

et al. 1999

Macromol. Chem. Phys.

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SUMMARY: The orientation of main-chain segments of some polysiloxanes containing mesogenic side groups was estimated by 29 Si NMR under high-power proton decoupling. The second-order orientation degree pP 2 P related to the orientation distribution of chemical shift tensors was calculated from the spectra. From this conclusions were drawn about the degree of segment orientation for which a discussion of the transverse orientation distribution was necessary. It turns out that most of the samples investigated here have a structure in which the main-chain segments are perpendicular to the director field; however, if this conformation involves sterical hindrance, a parallel arrangement can arise. The apparent contradiction to SANS data concerning backbone conformation of such polymers is discussed; thereby it is noted that in some cases the two methods take a somewhat different point of view. Thus, without further structural information, there is no unambiguous connection between mutual orientation of main and side chains on the one hand and the average shape of the whole molecule on the other.

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Comparing X-ray studies of smectic A phases formed by laterally branched molecules

Cited by 36 publications

References 10 publications

Synthesis and Liquid Crystalline Studies of 2,4-bis(4'-n-nonyloxybenzoyloxy)benzylidene-4''-n-alkoxyaniline

Synthesis and Liquid Crystalline Studies of 2,4-bis(4'-n-nonyloxybenzoyloxy)benzylidene-4''-n-alkoxyaniline

Substitution Effects on the Liquid Crystalline Properties of Thermotropic Liquid Crystals Containing Schiff Base Chalcone Linkages

Mutual orientation of main chains and side chains in nematic liquid-crystalline side-chain polysiloxanes

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