- A mitochondria-targeted mass spectrometry probe to detect glyoxals: Implications for diabetes
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The glycation of protein and nucleic acids that occurs as a consequence of hyperglycemia disrupts cell function and contributes to many pathologies, including those associated with diabetes and aging. Intracellular glycation occurs after the generation of the reactive 1,2-dicarbonyls methylglyoxal and glyoxal, and disruption of mitochondrial function is associated with hyperglycemia. However, the contribution of these reactive dicarbonyls to mitochondrial damage in pathology is unclear owing to uncertainties about their levels within mitochondria in cells and in vivo. To address this we have developed a mitochondria-targeted reagent (MitoG) designed to assess the levels of mitochondrial dicarbonyls within cells. MitoG comprises a lipophilic triphenylphosphonium cationic function, which directs the molecules to mitochondria within cells, and an o-phenylenediamine moiety that reacts with dicarbonyls to give distinctive and stable products. The extent of accumulation of these diagnostic heterocyclic products can be readily and sensitively quantified by liquid chromatography-tandem mass spectrometry, enabling changes to be determined. Using the MitoG-based analysis we assessed the formation of methylglyoxal and glyoxal in response to hyperglycemia in cells in culture and in the Akita mouse model of diabetes in vivo. These findings indicated that the levels of methylglyoxal and glyoxal within mitochondria increase during hyperglycemia both in cells and in vivo, suggesting that they can contribute to the pathological mitochondrial dysfunction that occurs in diabetes and aging.
- Pun, Pamela Boon Li,Logan, Angela,Darley-Usmar, Victor,Chacko, Balu,Johnson, Michelle S.,Huang, Guang W.,Rogatti, Sebastian,Prime, Tracy A.,Methner, Carmen,Krieg, Thomas,Fearnley, Ian M.,Larsen, Lesley,Larsen, David S.,Menger, Katja E.,Collins, Yvonne,James, Andrew M.,Kumar, G.D. Kishore,Hartley, Richard C.,Smith, Robin A.J.,Murphy, Michael P.
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Read Online
- Synthesis, liquid crystalline properties and photo switching properties of coumarin-azo bearing aliphatic chains: Application in optical storage devices
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A series of novel azo-coumarin derivatives with different aliphatic chain length (3a-e) have been synthesized and characterized for liquid crystal properties and their photoswitching behavior. The incorporation of coumarin along with azobenzene was prepared via esterification reaction and differ in the length of alkyl group, CnH2n+1, where n = 6, 8, 10, 12 and 14. Azo-coumarin bearing C14 alkyl chain shows Smectic–A phase while azo-coumarin bearing rest of long alkyl chain exhibited Nematic phase. The incorporation of natural product moieties into azobenzene network has increased electron delocalisation and liquid crystal properties. The photoswitching properties of said molecules were tested and the coumarin-azo compounds 3a-e took ~46 s to reach photostationary state during UV illumination and exhibited long thermal back relaxation time (~16 h) in solutions. Device is also fabricated to see the performance of the device with respect to the alkyl chain length. Presented studies show the importance of azo-coumarin derivatives with different chain length for the application of optical storage devices.
- Madiahlagan, Eswaran,B N, Sunil,Ngaini, Zainab,Hegde, Gurumurthy
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- Columnar self-assembly of bowl shaped fluorescent liquid crystals based on calix[4]arene with Schiff base units
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A new family of bowl-shaped molecules with a calix[4]arene rigid core and appended on four-sides, that display a wide range of hexagonal columnar phases, has been synthesised and well characterized. The thermal behaviours of the present compounds were established using a combination of polarising optical microscopy (POM), differential scanning calorimetry (DSC) and a high-temperature powder X-ray diffraction method (XRD). It is found that all of the synthesised materials show an enantiotropic hexagonal columnar liquid crystal phase. The structural and conformation characterization of these newly synthesised compounds was achieved by FT-IR, 1H NMR, and 13C NMR spectroscopy. All of the synthesised compounds exhibited good blue luminescence in solution under long wavelength UV light. To explore the structure property correlations, the alkoxy side chain group was varied from a lower alkyl spacer to a higher alkyl spacer on the lower rim of the calix[4]arene. The present research specified that the introduction of linking groups on the lower rim with an n-alkoxy side group is an influential approach to obtaining a supramolecular bowl shape liquid crystal which has good thermal and photophysical behaviour.
- Sharma, Anuj S.,Sharma, Vinay S.,Vekariya, Rajesh H.
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supporting information
p. 15044 - 15051
(2018/09/29)
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- Synthesis and mesomorphic properties of 2,4-bis(4′-n-pentyloxybenzoyloxy)- benzylidine-4″- n-alkoxyaniline
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The synthesis and mesomorphic properties of a new series of 2,4-bis(4′-npentyloxybenzoyloxy)- benzylidine-4″ -n-alkoxyaniline (DC5An) are reported. The molecular structure of compounds was confirmed by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analysis. The mesomorphic properties were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) measurements. All compounds of the series exhibit nematic (N) and smectic C (SmC) phases. The first four homologues (DC5A1-DC5A4) display a N mesophase, whereas the highest homologues (DC5A5-DC5A10) exhibit an enantiotropic dimorphism N and SmC phases. The mesomorphic properties of the present series are compared and discussed with other structurally related series.
- Hamad, Wali M.,Azeez, Hashim J.,Al-Dujaili, Ammar H.
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- AZOBENZENE COMPOUND AND HEAT PUMP SYSTEM USING THE SAME
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PROBLEM TO BE SOLVED: To provide an azobenzene compound capable of repeated structural changes without heating, and a heat pump system using the same. SOLUTION: An azobenzene compound represented by the general formula (1) and undergoing cis-trans isomerization reaction upon light irradiation is used as a heat medium of a heat pump system. In the formula, at least one of R1 to R3 is (CH2CH2O)n-R10; R4 is R11, O-R11, NH-R11, or COO-R11; X- is Cl-, Br-, I-, BF4-, PF6-, CH3(CH2)nSO3-, TsO-, (YSO2)2 N-, or (NC)2 N-; n is an integer between 0 and 2; and Y is F, CF3, or C2F5. COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0044; 0046
(2016/10/10)
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- Photoliquefiable ionic crystals: A phase crossover approach for photon energy storage materials with functional multiplicity
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Ionic crystals (ICs) of the azobenzene derivatives show photoinduced IC-ionic liquid (IL) phase transition (photoliquefaction) upon UV-irradiation, and the resulting cis-azobenzene ILs are reversibly photocrystallized by illumination with visible light. The photoliquefaction of ICs is accompanied by a significant increase in ionic conductivity at ambient temperature. The photoliquefaction also brings the azobenzene ICs further significance as photon energy storage materials. The cis-IL shows thermally induced crystallization to the trans-IC phase. This transition is accompanied by exothermic peaks with a total ΔH of 97.1 kJmol-1, which is almost double the conformational energy stored in cisazobenzene chromophores. Thus, the integration of photoresponsive ILs and self-assembly pushes the limit of solar thermal batteries.
- Ishiba, Keita,Morikawa, Masa-Aki,Chikara, Chie,Yamada, Teppei,Iwase, Katsunori,Kawakita, Mika,Kimizuka, Nobuo
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supporting information
p. 1532 - 1536
(2015/02/05)
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- AZOBENZENE COMPOUND AND HEAT PUMP SYSTEM USING IT
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PROBLEM TO BE SOLVED: To provide an azobenzene compound capable of changing a structure repeatedly without heating and a heat pump system using it. SOLUTION: An azobenzene compound expressed by the formula (1) and reacts by cis-trans isomerization by light radiation, is used as a heat medium of a heat pump system. The azobenzene compound expressed by the formula (1) is subjected to endotherm by melting latent heat when phase change from a solid phase trans body to a liquid phase cis body occurs, and is subjected to heat evolution when phase change from the liquid phase cis body to the solid phase trans body occurs. COPYRIGHT: (C)2015,JPO&INPIT
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Paragraph 0049; 0050
(2017/02/24)
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- A molecular insight on the supramolecular assembly of thiophene polymers
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Herein, the relationship between supramolecularly self-assembled microstructures and the chemical structures of photoluminescent molecules is discussed. A series of non-amphiphilic molecules with different length alkyl chains (4-14), central mesogenic groups, and chemical linkers were designed and synthesized. Intricate analysis shows that the supramolecular assembly varies with change in torsion angle of the thiophene linking group on elongation of the alkyl chain. Small angle X-ray scattering measurement shows long range molecular interaction for lower alkyl chain length, AFM reveals circular domains for octyl and decyl alkyl group polymers. UV-Visible and photoluminescence studies in solution and thin-film show that the J-aggregate patterns for the circular domain of the polymer backbone has a major effect on the polymer absorbance, and produces a larger shift for the photoluminescence signals at higher wavelengths. Excitation polarisation studies show a change in molecular ordering in various colour regions with change in aggregation by means of maximum dichroic ratio for the circular domain assembly. Charge carrier mobility and cyclic voltammetry studies show higher mobility and reduced band gap for these circular domain polymers. Dynamic light scattering studies of octyl alkyl chain polymers show a bimodal distribution, which shows the apparent nature of anisotropy in solution. The Royal Society of Chemistry.
- Suryanarayanan, Chandrasekaran,Ravindran, Ezhakudiyan,Ananthakrishnan, Soundaram Jeevarathinam,Somanathan, Narayanasastri,Mandal, Asit Baran
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p. 18975 - 18982
(2012/10/29)
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- Synthesis of novel triarylamine-based dendrimers with N4,N 6-dibutyl-1,3,5-triazine-4,6-diamine probe for electron/energy transfers in H-bonded donor-acceptor-donor triads and as efficient Cu 2+ sensors
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Two novel highly soluble triarylamine dendrimers TPAD1 and TPAD2 with N4,N6-dibutyl-1,3,5-triazine-4,6-diamine probe were synthesized via normal synthetic routes. Both dendrimers (TPAD1 and TPAD2) form H-bonded donor-acceptor-donor (D-A-D) supramolecular triads TPAD1-PBI-TPAD1 and TPAD2-PBI-TPAD2 with 3,4,9,10-perylene tetra carboxylic diimide derivative (PBI). The presence of multiple H-bonds in the solution state was elucidated by 1H NMR titrations and IR spectral studies. J-aggregations and electron/energy transfers provided by both dendrimers were verified by UV-Vis and photoluminescence (PL) titrations with PBI and the particle sizes of supramolecular triads were calculated by X-ray diffraction (XRD) analysis. Similarly, both dendrimers also showed sensitivities towards Cu2+ in comparison with 19 interfering metal ions, which were evidenced via UV-Vis and PL titraions in both single and dual metal systems. The maximum detection limit of Cu2+ ions was determined to be 20 ppm from PL titrations for both dendrimers, and the 1:2 stoichiometry of the complexes formed by both dendrimers (TPAD1-Cu2+ and TPAD2-Cu2+) were calculated by Job plots based on UV-Vis absorption titrations. More importantly, the binding mechanism of the 1,3,5-triazine-4,6-diamine probe of both dendrimers was well characterized by 1H and 13C NMR titrations ([D 8]THF:D2O = 2:1 in vol.) and supported by the fluorescence reversibility by adding metal ions and PMDTA sequentially.
- Shellaiah, Muthaiah,Rajan, Yesudoss Christu,Lin, Hong-Cheu
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supporting information
p. 8976 - 8987
(2013/01/13)
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- Studies of calamitic liquid crystalline compounds involving ester-azo central linkages with a biphenyl moiety
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Two mesogenic homologous series involving ester-azo central linkages with a biphenyl moiety have been synthesized, such as 4'-[(4-n-alkoxyphenyl)diazenyl] biphenyl-4-ol (series I) and 4'-[(4-n-alkoxyphenyl) diazenyl]-4-butoxy phenyl biphenyl-4-carboxylate (series II). Azobiphenyl of series I having a free hydroxyl group with strong hydrogen bonding exhibits a high-temperature enantiotropic smectic phase. Whereas in series II, compounds containing C 1-C8 carbon atoms exhibit only a monotropic smectic phase and compounds with C10, C12, C14, and C 16 atoms show an enantiotropic smectic phase. These compounds were characterized by elemental analysis, FT-IR, 1H-NMR, and mass spectral studies. The phase transition and mesogenicity of these substances were studied by polarizing optical microscopic and differential scanning calorimetric techniques. Their thermal stabilities and other characteristics are discussed. Copyright Taylor &Francis Group, LLC.
- Thaker,Dhimmar,Patel,Solanki,Patel,Chothani,Kanojiya
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experimental part
p. 172 - 191
(2012/07/27)
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- Role of terminal heterocyclic ring on mesomorphic properties of homologous series
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Two new homologous series of compounds with a heterocyclic ring having sulfur and oxygen as a hetero atom derived from p-hydroxy acetophenone and alkoxy aniline containing cinnamate-azomethine as central linkages have been synthesized. viz. 4(furalacryloxy) α-methyl benzylidine-4′-alkoxy aniline and 4(thianylacryloxy) α-methyl benzylidine-4′-alkoxy aniline. The compound of both the series have been characterized by elemental analysis, FT-IR, 1H-NMR, and mass spectrometry method. Their liquid crystalline properties have been investigated by optical polarizing microscopy and differential scanning calorimetry (DSC) studies. All the derivatives are mesomorphic in nature showing the nemetic phase. The mesomorphic properties of the present two series are compared with other structurally related series to evaluate the effect of thiophene and furan on mesomorphism. Copyright Taylor & Francis Group, LLC.
- Thaker,Patel,Solanki,Dhimmer,Dave
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experimental part
p. 63 - 80
(2010/09/05)
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- Azomesogens having a lateral hydroxy substituent
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Two homologous series of liquid crystalline azoesters consisting of a lateral hydroxyl substituent on the central benzene ring at 2' positions have been synthesized and thermally characterized. All the 24 members, of both series, exhibit high temperature nematic phases. All the compounds of both series are thermally stable and exhibit a wide mesomorphic range. The homologues have been characterized using Infra Red (IR), Nuclear Magnetic Resonance Spectroscopy (NMR), and Differential Scanning Calorimetry (DSC). Their mesomorphic properties and other characteristics are discussed.
- Dixit, Sandhya,Vora
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experimental part
p. 43 - 52
(2010/04/02)
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- Mesogenicity of organophosphazenes: The effect of phosphazene rings and side groups on the phase transition
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Cyclotriphosphazene and cyclotetraphosphazene derivatives with mesogenic 4-N-(4-alkoxyphenyl)iminomethyl)phenoxy and 4-(4′-alkoxy) biphenoxy moieties were synthesized. Schiff base moiety has higher mesomorphic stability than that in biphenyl moiety both in cyclotriphosphazene and cyclotetraphosphazene. Cyclotriphosphazenes possess higher thermal stability in the mesomorphic phase than the cyclotetraphosphazenes, suggesting the difference in the molecular structure.
- Moriya, Keiichi,Yamane, Toshihiro,Suzuki, Toshiya,Masuda, Tsuyoshi,Mizusaki, Hiroshi,Yano, Shinichi,Kajiwara, Meisetsu
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p. 1427 - 1432
(2007/10/03)
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- Synthesis and structure of 1,4-diazabutadiene liquid crystals
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Nine 1,4-diazabutadiene compounds, Ar-N=C(R)-C(R)=N-Ar, R=H, Me; Ar= H2n+1CnO-C6H4, 2,4-(H9C4O)(Me)-C6H3 were synthesized and their liquid crystal properties were studied through thermal polarizing microscopy. The X-ray single crystal structure of compound 9 (Ar-N=C(H)-C(H)=N-Ar, Ar=2,4-(Me)(H9C4O)C6H3) was tested. It is a monoclinic crystal system, space group P21/C with the unit cell parameters: a=7.0703(3)A, b=8.674(4)A, c=18.3115(8)A, β =95.392(1)°. V=1114.57(9)A3, z=2, Dc=1.134 Mg/m3, R=0.0490,Rw=0.1237.
- Zhao, Ke-Qing,Hu, Pin,Xu, Hong-Bo
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p. 801 - 808
(2007/10/03)
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- Effect of Molecular Structure on Mesomorphism. 22. Liquid Crystalline 1-Alkanol Derivatives
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Several 1-alkanols having a mesogenic unit attached to the omega-carbon have been prepared.Many of these are liquid crystalline.The nematic mesophase is predominant for these materials.This is presumably due to intermolecular hydrogen-bonding between polar terminal groups such as cyano or nitro and the primary hydroxyl functionality of a proximal molecule.The resulting end-to-end association favors a nematic mesophase.
- Griffin, A. C.,Vaidya, S. R.
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