Dependence of Mesomorphic Behaviour of Methylene-Linked Dimers and the Stability of the N_TB/N_X Phase upon Choice of Mesogenic Units and Terminal Chain Length

TY - JOUR

T1 - Dependence of Mesomorphic Behaviour of Methylene-Linked Dimers and the Stability of the NTB/NX Phase upon Choice of Mesogenic Units and Terminal Chain Length

AU - Mandle, Richard J.

AU - Goodby, John W.

N1 - © 2016 Wiley-VCH Verlag GmbH & Co. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2016/6/23

Y1 - 2016/6/23

N2 - Twelve symmetrical dimeric materials consisting of a nonamethylene (C9) spacer and either phenyl 4-(4'-alkylphenyl)benzoate, phenyl 4-(4'-alkylcyclohexyl)benzoate or phenyl 4-(4'-alkylbicyclohexyl)carboxylate mesogenic units were prepared and their mesogenic behaviour characterised by POM, DSC and XRD. All of the materials exhibited nematic phases with clearing points in excess of 200°C. Four compounds were found to exhibit the twist-bend nematic phase, with one material exhibiting a transition from the NTB phase into an anticlinic smectic 'X' phase. Across all three series of compounds the length of terminal chain is seen to dictate, to some degree, the type of mesophase formed: shorter terminal chains favour nematic and NTB mesophases, whereas longer terminal aliphatic chains were found to promote smectic phases.

AB - Twelve symmetrical dimeric materials consisting of a nonamethylene (C9) spacer and either phenyl 4-(4'-alkylphenyl)benzoate, phenyl 4-(4'-alkylcyclohexyl)benzoate or phenyl 4-(4'-alkylbicyclohexyl)carboxylate mesogenic units were prepared and their mesogenic behaviour characterised by POM, DSC and XRD. All of the materials exhibited nematic phases with clearing points in excess of 200°C. Four compounds were found to exhibit the twist-bend nematic phase, with one material exhibiting a transition from the NTB phase into an anticlinic smectic 'X' phase. Across all three series of compounds the length of terminal chain is seen to dictate, to some degree, the type of mesophase formed: shorter terminal chains favour nematic and NTB mesophases, whereas longer terminal aliphatic chains were found to promote smectic phases.

KW - Bimesogens

KW - Liquid-crystalline dimers

KW - Mesomorphism

KW - Nematic phase

KW - X-ray diffraction

UR - http://www.scopus.com/inward/record.url?scp=84971659695&partnerID=8YFLogxK

U2 - 10.1002/chem.201601146

DO - 10.1002/chem.201601146

M3 - Article

AN - SCOPUS:84971659695

SN - 0947-6539

VL - 22

SP - 9366

EP - 9374

JO - Chemistry : A European Journal

JF - Chemistry : A European Journal

IS - 27

ER -