The crystal and molecular structure of three homologue 1,4‐dialkanoyloxy‐biphenyls (SYM‐<i>n</i>)

Thyen, W.; Zugenmaier, P.

doi:10.1002/crat.2170290425

Cited by 8 publications

(1 citation statement)

References 3 publications

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“…Thyen [ 9 ] then increased the number of available compounds synthesizing BP- n from n = 1 to 19 and investigated the physical properties including the liquid crystalline phase behavior comprehensively as well as their classification for compounds with n ≥ 5, which exhibit highly ordered smectic phases, most probably SmG as high temperature phase. Some selected crystal structures have been determined in his doctoral thesis [ 9 ] and in two publications [ 4 , 5 ]. The homologous series investigated may serve as low molecular mass models for liquid crystalline polyester as studied by Krigbaum [ 14 ] and provide insights to molecules with a stiff biphenyl center part and flexible aliphatic tail groups.…”

Section: Discussion Of the Crystallographic Structuresmentioning

confidence: 99%

Review of Crystalline Structures of Some Selected Homologous Series of Rod-Like Molecules Capable of Forming Liquid Crystalline Phases

Zugenmaier

2011

IJMS

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The crystal structures of four homologous series of rod-like molecules are reviewed, two of which form hydrogen bonds and two with a symmetric chemical constitution. Many of the compounds investigated turn into liquid crystalline phases upon temperature increase. It is of valuable interest to know possible conformations and possible packing arrangements as prerequisites to model liquid crystalline structures. The hydrogen bonds of homologous series of pure 4-(ω-hydroxyalkyloxy)-4′-hydroxybiphenyl (HnHBP, n the alkyloxy tail length) are realized through head to tail arrangements of the hydroxyl groups and crystallize except one compound in chiral space groups without the molecules containing any asymmetric carbon. The hydrogen bonds of the homologous series of 4-substituted benzoic acids with various lengths of the tail provide dimers through strong polar bonding of adjacent carboxyl groups and thus provide the stiff part of a mesogenic unit prerequisite for liquid crystalline phases. The homologous series of dialkanoyloxybiphenyls (BP-n, n = 1, 19), of which nine compounds could be crystallized, show liquid crystalline behavior for longer alkane chain lengths, despite the high mobility of the alkane chain ends already detectable in the crystal phase. A single molecule, half a molecule or two half molecules form the asymmetric unit in a centrosymmetric space group. The homologous series of 1,4-terephthalidene-bis-N-(4′-n-alkylaniline) (TBAA-n) exhibit a large variety of packing arrangements in the crystalline state, with or without relying on the symmetry center within the molecules.

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Section: Discussion Of the Crystallographic Structuresmentioning

confidence: 99%

Review of Crystalline Structures of Some Selected Homologous Series of Rod-Like Molecules Capable of Forming Liquid Crystalline Phases

Zugenmaier

2011

IJMS

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13C NMR chemical shift as a probe for estimating the conformation of aromatic groups in the solid state. 1. Biphenyls

et al. 2000

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The relationships between 13C NMR chemical shifts of aromatic carbons and the inter‐ring torsion angles (θ) of two phenyl rings in biphenyl and its substituted derivatives were systematically examined. The chemical shifts of C1, C2 and C6 carbons (δC1, δC2 and δC6) of the biphenyl group in the solid state show systematic correlations with θ when the substituent shielding effects are removed from the solid chemical shifts by subtracting the solution chemical shifts or subtracting the substituent shielding parameters. The substituent parameters deduced from substituted benzenes are utilized for the calculation. An increase in δC1, δC2 or δC6 (high‐frequency displacement of the signals) corresponds to an increase in θ. In particular, δC6 can be a good measure of θ when no substituents are attached to C6. The isotropic nuclear shielding calculated using ab initio molecular orbital theory with the GIAO‐CHF method for the biphenyl agree well with the experimental results. The relationships between the 13C chemical shifts and the inter‐ring torsion angle can be used to estimate the conformation of biphenyl groups incorporated into aromatic and/or liquid crystalline compounds and polymers. Copyright © 2000 John Wiley & Sons, Ltd.

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The Crystal and Molecular Structure of Mesomorphic 1,4‐Dipentadecanoyloxy‐biphenyl (SYM‐14)

Thyen

Kaiser

Zugenmaier

1995

Cryst. Res. Technol.

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The crystal and molecular structure of three homologue 1,4‐dialkanoyloxy‐biphenyls (SYM‐n)

Abstract: The three homologue compounds with the general formula CnHln+ -COO -C6H, -C6H, -OOC-C,H,,+ (SYM-n) crystallize in the following space groups: SYM-1: triclinic, P i , a = 7.400(6),

Cited by 8 publications

References 3 publications

Review of Crystalline Structures of Some Selected Homologous Series of Rod-Like Molecules Capable of Forming Liquid Crystalline Phases

Review of Crystalline Structures of Some Selected Homologous Series of Rod-Like Molecules Capable of Forming Liquid Crystalline Phases

13C NMR chemical shift as a probe for estimating the conformation of aromatic groups in the solid state. 1. Biphenyls

The Crystal and Molecular Structure of Mesomorphic 1,4‐Dipentadecanoyloxy‐biphenyl (SYM‐14)

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