Roles of sigmatropic migration of a benzoyl group and intermolecular hydrogen bonding between a tropone carbonyl and an NH group on the mesomorphic properties of 2-(4-alkoxybenzoyloxy)-5-alkylaminotropones and 5-alkoxy-2-(4-alkylaminobenzoyloxy)tropo

Mori, Akira; Kato, Nobuo; Takeshita, Hitoshi; Nimura, Ryuko; Isobe, Masao; Jin, Can; Ujiie, Seiji

doi:10.1080/02678290110067245

Cited by 12 publications

(3 citation statements)

References 13 publications

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“…Furthermore, we measured the 1 H NMR spectra of This suggests that intramolecular hydrogen bonding of the NH group is the major driving force for gelation, rather than intermolecular hydrogen bonding. Additionally, as observed previously, X-ray crystallographic analysis of the amide troponoid 10 [11] revealed that the core part is almost flat as a result of intramolecular hydrogen bonding between NH and the tropone carbonyl group, whereas the core part of ester 11 [12] is twisted. Flat troponoid amides, therefore, should have a tighter packing structure than twisted troponoid esters.…”

Section: Methodsmentioning

confidence: 58%

Low Molecular Weight Gelators with Hexagonal Order in Their Liquid‐Crystal Phases and Gel States: 5‐Cyano‐2‐(3,4,5‐trialkoxybenzoylamino)tropones

Hashimoto

Ujiie

Mori³

2003

Advanced Materials

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In summary, we have prepared soluble, highly crystalline, monodisperse, and size-controlled In 2 O 3 nanoparticles by thermal decomposition of In(acac) 3 in oleylamine under inert atmosphere. The oxygen in the nanoparticles apparently originates from the acetylacetonate ligand in the In(acac) 3 precursor. The particle size of In 2 O 3 can be easily manipulated by changing the experimental conditions, and a weak size dependence of photoluminescence is demonstrated. The high solubility of the prepared oleylamine-capped In 2 O 3 nanoparticles in various organic solvents and the ready formation of a superlattice on a flat surface promise potential utilization of their size-dependent properties and the facile fabrication of nanodevices. ExperimentalPreparation of 6 nm In 2 O 3 Nanoparticles (Sample B): A slurry of 0.3 g In(acac) 3 in 2.34 g oleylamine (1:12 molar ratio) was heated at 250 C for 7 h under an atmosphere of argon, and the resulting reaction mixture was cooled to room temperature to form a brown, viscous oil. Dichloromethane (10 mL) was added to enhance the fluidity of the reaction mixture, and insoluble precipitates were removed by centrifugation. To the resulting brown solution was added excess ethanol (40 mL) to form a pale yellow precipitate. Centrifugation and repeated washing with ethanol gave a pale yellow powder, which can be easily re-dispersed in various organic solvents such as hexane, toluene, and dichloromethane.Preparation of 4 nm In 2 O 3 Nanoparticles (Sample A): A slurry of In(acac) 3 (0.075 g, 0.18 mmol) and oleylamine (2.34 g, 8.73 mmol, 48 equiv.) was used.Preparation of 8 nm In 2 O 3 Nanoparticles (Sample C): A slurry of In(acac) 3 (0.30 g, 0.73 mmol) and oleylamine (2.34 g, 8.73 mmol, 12 equiv.) in a 100 mL Schlenk flask connected to a bubbler was purged with argon for 20 min and then heated at 250 C for 7 h under an argon atmosphere. Solid In(acac) 3 (0.15 g, 0.36 mmol) was added to the reaction mixture against an argon stream and the resulting solution was heated at 250 C for 1 h; this step was repeated once more. Additional In(acac) 3 (0.15 g, 0.36 mmol) was added, and the reaction mixture was aged at 250 C for 7 h under an argon atmosphere.Characterization of In 2 O 3 Nanoparticles: The prepared nanoparticles were characterized by XRD (Rigaku D/MAX-RC (12 kW) diffractometer using graphite-monochromatized Cu Ka radiation at 40 kV and 45 mA), TEM (low resolution: Omega EM912 operated at 120 kV; high resolution: Philips F20Tec-nai operated at 200 kV), selected area electron diffraction (SAED) patterns attached to EM912, and energy dispersive X-ray analysis (EDX) attached to EM912. UV-vis absorption spectra were recorded on a Jasco V530 spectrophotometer. Photoluminescence measurements (Spex Fluorolog-3) were performed using an excitation wavelength of 275 nm with a 450 W Xe arc lamp at room temperature. Samples for TEM investigations were prepared by putting an aliquot of dichloromethane solution of In 2 O 3 nanoparticles onto an amorphous carbon substrate supported on a copper grid....

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Section: Methodsmentioning

confidence: 58%

Low Molecular Weight Gelators with Hexagonal Order in Their Liquid‐Crystal Phases and Gel States: 5‐Cyano‐2‐(3,4,5‐trialkoxybenzoylamino)tropones

Hashimoto

Ujiie

Mori³

2003

Advanced Materials

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“…The corresponding benzenoids were similarly synthesised (Scheme 2). The nuclear magnetic resonance (NMR) spectra of troponoids 1-6 with a benzoyloxy group at the C-2 position are characteristic as observed in 2-acyloxytropones [8][9][10][11][12]. The patterns of the NMR spectra are largely dependent on the measuring temperature.…”

Section: Synthesismentioning

confidence: 96%

“…In this paper, we synthesise 2,5-dibenzoyloxytropones (1)(2)(3), 5-benzoylamino-2-benzoyloxytropones (4)(5)(6), and 2,5-dibenzoylaminotropones (7)(8)(9) with mono-, di-, and tri-alkoxy groups on the benzoyl group and the corresponding benzenoids (10)(11)(12)(13)(14)(15)(16)(17)(18) to discuss the difference in mesomorphic properties depending on the core structures as well as the connecting groups.…”

Section: Introductionmentioning

confidence: 99%

Mesomorphic property of 2,5-dibenzoyloxy-, 5-benzoylamino-2-benzoyloxy-, and 2,5-dibenzoylamino-tropones with mono-, di-, and tri-alkoxyl groups on the benzoyl groups and their benzenoid derivatives

Mori¹,

Itoh²,

Taya³

et al. 2010

Liquid Crystals

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Mesomorphic properties of three-ring systems such as 2,5-dibenzoyloxytropones, 5-benzoylamino-2-benzoyloxytropones and 2,5-dibenzoylaminotropones with 4-alkoxy, 3,4-dialkoxy, and 3,4,5-trialkoxy groups on the benzoyl groups were investigated together with those of the corresponding benzenoids. Derivatives with two monoalkoxybenzoyl groups showed nematic and smectic A and C phases. Troponoid tetracatenars with two dialkoxybenzoyl groups had hexagonal columnar phases except for troponoids with two ester-connecting groups, whereas the corresponding benzenoids with two dialkoxybenzoyl groups were non-mesomorphic. All troponoid hexacatenars with two trialkoxybenzoyl groups formed hexagonal columnar phases. With the exception of benzenoid hexacatenars with two ester-connecting groups, the benzenoid hexacatenars showed hexagonal and tetragonal columnar phases. These mesomorphic properties were discussed from the standpoint of the difference of the core structure and the connecting group, where the amide-connecting group played a role to induce and enhance mesomorphic properties through hydrogen bonding.

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Troponoid metallomesogens with 5-alkoxy, 5-alkoxycarbonyl, 5-alkanoyloxy, 5-alkyl, 5-alkoxy-2-amino, and 5-alkoxy-2-alkylamino substituents

Mori

Takemoto

et al. 2005

J. Mater. Chem.

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Metal complexes (Cu, VO, Zn, Mn, and Ni) with 5-alkoxy-, 5-alkoxycarbonyl-, 5-alkanoyloxy-, and 5-alkyl-tropolonato structures as well as bis(5-alkoxy-2-aminotroponato)copper were synthesized. All bistropolonato Cu complexes showed ordered smectic phases such as hexatic smectic B, smectic G(J), and smectic H phases. The Zn, Mn, and Ni complexes were nonmesomorphic whereas the VO complexes with 5-alkoxy-and 5-alkanoyloxy-tropolonato groups had mesophases. Among the Cu complexes, bis(5-alkanoyloxytropolonato)copper complex had the highest clearing point. The mesomorphic properties depend on the kinds of substituents, metal ions, and heteroatoms of the core. The Cu complexes have a square planar coordination structure and the VLO complexes a square pyramidal one. The thermal stability of the Cu complexes was explained by the size and symmetry of the core structure. To decrease the transition temperatures of bis(5-alkoxytropolonato)copper complexes, secondary alkoxyl groups were introduced at the C-5 positions and the two oxygen atoms of the bistropolonato core were replaced by two nitrogen atoms, which reduced the symmetry of the structure.

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Roles of sigmatropic migration of a benzoyl group and intermolecular hydrogen bonding between a tropone carbonyl and an NH group on the mesomorphic properties of 2-(4-alkoxybenzoyloxy)-5-alkylaminotropones and 5-alkoxy-2-(4-alkylaminobenzoyloxy)tropo

Cited by 12 publications

References 13 publications

Low Molecular Weight Gelators with Hexagonal Order in Their Liquid‐Crystal Phases and Gel States: 5‐Cyano‐2‐(3,4,5‐trialkoxybenzoylamino)tropones

Low Molecular Weight Gelators with Hexagonal Order in Their Liquid‐Crystal Phases and Gel States: 5‐Cyano‐2‐(3,4,5‐trialkoxybenzoylamino)tropones

Mesomorphic property of 2,5-dibenzoyloxy-, 5-benzoylamino-2-benzoyloxy-, and 2,5-dibenzoylamino-tropones with mono-, di-, and tri-alkoxyl groups on the benzoyl groups and their benzenoid derivatives

Troponoid metallomesogens with 5-alkoxy, 5-alkoxycarbonyl, 5-alkanoyloxy, 5-alkyl, 5-alkoxy-2-amino, and 5-alkoxy-2-alkylamino substituents

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