Synthesis and properties of mono-substituted liquid crystalline polyacetylene derivatives—doping, magnetic orientation, and photo-isomerization

Goto, Hiromasa; Nimori, Shigeki; Akagi, Kazuo

doi:10.1016/j.synthmet.2005.09.044

Cited by 17 publications

(12 citation statements)

References 34 publications

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“…Aqueous work-up achieved the aldehydes in excellent yields of up to 98%. NMR spectroscopic results were found to be in good accordance with the data published elsewhere [27–30]. …”

Section: Resultssupporting

confidence: 89%

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

Weiss¹,

Reichel²,

Görls³

et al. 2017

Beilstein J. Org. Chem.

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Eight difluoroboron complexes of curcumin derivatives carrying alkyne groups containing substituents have been synthesized following an optimised reaction pathway. The complexes were received in yields up to 98% and high purities. Their properties as fluorescent dyes have been investigated. Furthermore, a strategy for the hydrolysis of the BF2 group has been established using aqueous methanol and sodium hydroxide or triethylamine.

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“…Aqueous work-up achieved the aldehydes in excellent yields of up to 98%. NMR spectroscopic results were found to be in good accordance with the data published elsewhere [27–30]. …”

Section: Resultssupporting

confidence: 89%

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

Weiss¹,

Reichel²,

Görls³

et al. 2017

Beilstein J. Org. Chem.

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“…In research on LC materials, conjugated polymers with an LC phase under appropriate conditions are of particular interest, offering both electrical conductivity and self-organized properties [ 17 , 18 , 19 ]. In the present study, a phenylene monomer bearing a pyrimidine-type LC group was synthesized, and the compound was demonstrated to exhibit both nematic and smectic phases.…”

Section: Introductionmentioning

confidence: 99%

Liquid Crystalline π-Conjugated Copolymers Bearing a Pyrimidine Type Mesogenic Group

Kawabata

Goto

2009

Materials

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Phenylene-thiophene-based liquid crystalline π-conjugated copolymers bearing mesogenic groups as side chains were synthesized via a Stille polycondensation reaction and confirmed to exhibit a nematic liquid crystal phase at appropriate temperatures. The formation of a nematic phase, but not a smectic phase indicates cooperation of the main chain and side chain in the formation of a nematic main-chain/side-chain liquid crystal phase. The generation of polarons in the main chain as charge carriers during in-situ vapor doping of iodine is confirmed to increase with a doping progresses, exhibiting Dysonian paramagnetic behavior typical of conductive polymers.

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“…It is notable that the isomerization temperature for the cis to trans transformation in polyacetylenes is in the range of 150-200 1C. 12,13 The mesomorphic phase behavior during the first cooling scan is summarized in Table 3. LC textures are shown in Figure 2, and differential scanning calorimetry curves of poly(PSBPCN) are shown in Figure 3.…”

Section: Lc Propertiesmentioning

confidence: 99%

Synthesis of side-chain liquid crystalline polyacetylenes bearing succinic acid spacer

Mizuta

Hiraga

Koga

et al. 2010

Polym J

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Seven novel types of acetylene monomers, 4-oxo-4-(prop-2-ynyloxy)butanoic acid ester derivatives (PSRs), having ester groups of 4¢-substituted phenyl (PSPRs: -H¼PSP; -CN¼PSPCN; -OCH 3 ¼PSPOC 1 ) or 4¢-substituted biphenyl (PSBPRs: -H¼PSBP; -CN¼PSBPCN; -OCH 3 ¼PSBPOC 1 ; -O(CH 2 ) 5 CH 3 ¼PSBPOC 6 ) as a pendant group were synthesized from 4-oxo-4-(prop-2-ynyloxy)butanoic acid (PS) with phenol derivatives and polymerized with a rhodium-catalyzed system. The structures and properties of the polymers were characterized and evaluated by nuclear magnetic resonance, infrared spectroscopy and gel permeation chromatography analyses. The polymerizations of the PSRs were carried out under nitrogen with Rh catalysts in tetrahydrofuran or toluene at 30 1C, producing a good yield of polymers. The resulting polymer showed a thermotropic mesophase as observed through polarized optical microscopy and differential scanning calorimetry. Polymer Journal ( In side-chain LC polymers in which the mesogenic groups are linked through flexible alkyl or poly(alkylene oxide) chains to the polymer backbone, the flexible spacer enables a partial decoupling of the motions of the polymer backbone and the mesogens; thus, mesogens have the potential to adopt flexible behavior similar to that of low-molecular-weight LC compounds.Polyacetylene is a p-conjugated polymer with at least four possible conformations (cis-transoid, cis-cisoid, trans-transoid and transcisoid). Yashima and co-workers reported the synthesis of cis-transoidal poly((4-carboxyphenyl)acetylene) by the polymerization of (4-carboxyphenyl)acetylene using a rhodium catalyst. The synthesized polymer folded into a preferred-handed helical conformation on complexation with non-racemic primary amines and amino alcohols. 3,4 Unfortunately, 1-alkynes, which have flexible methylene spacers, show a low polymerization ability and give low sterically controlled polyacetylenes. However, Noyori and co-workers reported that (nbd)Rh + [Z 6 -(C 6 H 5 )-B À (C 6 H 5 ) 3 ], a zwitterionic Rh(I) complex, functions as an excellent initiator of the polymerization of alkylated and aromatic monosubstituted acetylenes without trialkylsilanes. 5 The propargyl group is one of the least expensive compounds and facilitates the synthesis of acetylene derivatives. Despite this, most polyacetylenes are prepared from 1-alkyne derivatives in studies on LC

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Synthesis and properties of mono-substituted liquid crystalline polyacetylene derivatives—doping, magnetic orientation, and photo-isomerization

Cited by 17 publications

References 34 publications

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

Liquid Crystalline π-Conjugated Copolymers Bearing a Pyrimidine Type Mesogenic Group

Synthesis of side-chain liquid crystalline polyacetylenes bearing succinic acid spacer

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Synthesis and properties of mono-substituted liquid crystalline polyacetylene derivatives—doping, magnetic orientation, and photo-isomerization

Cited by 17 publications

References 34 publications

Curcuminoid–BF2 complexes: Synthesis, fluorescence and optimization of BF2 group cleavage

Curcuminoid–BF2 complexes: Synthesis, fluorescence and optimization of BF2 group cleavage

Liquid Crystalline π-Conjugated Copolymers Bearing a Pyrimidine Type Mesogenic Group

Synthesis of side-chain liquid crystalline polyacetylenes bearing succinic acid spacer

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Product

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Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage

Curcuminoid–BF₂ complexes: Synthesis, fluorescence and optimization of BF₂ group cleavage