- Mesomorphic phase transition of a cyclotetraphosphazene containing schiff base moieties: Comparison with the corresponding cyclotriphosphazene
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Newly prepared octakis{4-[N-(4'- heptyloxyphenyl)iminomethyl]phenoxy}cyclotetraphosphazene, consisting of a cyclotetraphosphazene ring backbone and Schiff base sidechain groups has been found to generate an enantiotropic smectic A phase; this is a first e
- Moriya, Keiichi,Kawanishi, Yasuyuki,Yano, Shinichi,Kajiwara, Meisetsu
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- Selective Functionalization of Graphene at Defect-Activated Sites by Arylazocarboxylic tert-Butyl Esters
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The development of versatile functionalization concepts for graphene is currently in the focus of research. Upon oxo-functionalization of graphite, the full surface of graphene becomes accessible for C?C bond formation to introduce out-of-plane functional
- Halbig, Christian E.,Lasch, Roman,Krüll, Jasmin,Pirzer, Anna S.,Wang, Zhenping,Kirchhof, Jan N.,Bolotin, Kirill I.,Heinrich, Markus R.,Eigler, Siegfried
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p. 3599 - 3603
(2019/02/01)
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- Photoresponsive behavior of hydrophilic/hydrophobic-based novel azobenzene mesogens: Synthesis, characterization and their application in optical storage devices
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Three series of alkoxy chain-bearing azobenzene-derived quaternary ammonium iodides with an alkoxy chain at one end, namely N,N-diethanol-6-(4-((4′-alkyloxyphenyl)diazenyl)phenoxy)hexan-1-ammonium iodides, N-ethyl-N-ethanol-6-(4-((4′-alkyloxyphenyl)diazenyl)phenoxy)hexan-1-ammonium iodides and N,N-diethyl-6-(4-((4′-alkyloxyphenyl)diazenyl)phenoxy)hexan-1-ammonium iodides were synthesized and characterized. Their mesomorphic and photoswitching properties were examined via polarising optical microscopy (POM), differential scanning calorimetry (DSC) and UV-vis spectrophotometry. The liquid crystalline tilted schlieren texture of smectic C, non-tilted natural focal conic texture of smectic A and smectic B phases were observed in the N,N-diethanol- and N-ethyl-N-ethanol-bearing ammonium group substituted at the terminal via the alkoxy chain of the azo moiety. In these azo moieties, the equilibrium time for trans-cis isomerization was about 1 min and cis-trans isomerization occurred at around 590 min, which had the highest alkoxy chain and no hydroxyl group on their head group. The absence of a hydroxyl group on the terminal head group resulted in slow thermal back relaxation, whereas the hydroxyl group-bearing head group showed fast thermal back relaxation. These results suggest that the influence of the substituent on the cationic ammonium head group and alkoxy chain length on the photoisomerization of the azo compounds is vital for optical storage devices. Furthermore, the device fabricated using these materials demonstrated that they are excellent candidates for optical image storage applications.
- Sunil,Yam, Wan Sinn,Hegde, Gurumurthy
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p. 40588 - 40606
(2019/12/25)
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- Synthesis of N-Substituted Iminosugar Derivatives and Evaluation of Their Immunosuppressive Activities
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It is important to find more effective and safer immunosuppressants, because clinically used immunosuppressive agents have significant side effects. A series of N-substituted iminosugar derivatives were designed and synthesized, and their immunosuppressive effects were evaluated by the CCK-8 assay. The results revealed that iminosugars 10 e and 10 i, that is, (3R,4S)-1-(4-heptyloxylphenylethyl)pyrrolidine-3,4-diol and (3R,4S)-1-[2-(2-chloro-4-(p-tolylthio)-phenyl-1-yl)ethyl]pyrrolidine-3,4-diol, respectively, exhibited the strongest inhibitory effects on mouse splenocyte proliferation (IC50=2.16 and 2.48 μm, respectively), whereas the iminosugars containing an amide group near the hydrophilic head (compounds 10 j–n) exhibited no inhibitory effects. Further studies revealed that the inhibitory effects on splenocyte proliferation may have come from the suppression of both IFN-γ and IL-4 cytokines. Our results suggest that synthetic iminosugars, especially compounds 10 e and 10 i, hold potential as immunosuppressive agents.
- Lv, Zhuo,Song, Chengcheng,Niu, Youhong,Li, Qin,Ye, Xin-Shan
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p. 338 - 351
(2018/02/27)
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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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- Molecular flexibility operated mesomorphism by end groups in azoester series
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A novel azoester homologous series, RO?C6H4?COO?C6H4?N = N?C6H4?OC7H15(n) (para) has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on mesomorphic properties with reference to tthe flexible terminal chain. The novel azoester series consists of thirteen (C1–C18) members. Mesomorphism commences from C5 homologue. C1–C4 homologues are nonmesomorphic, C5 homologue is only nematogenic and C6–C18 homologues are smectogenic and nematogenic. All mesogenic homologues are enantiotropically mesomorphic. Transition temperatures and textures were determined by polarizing optical microscopy (POM) and a heating stage. Cr-M/I transition curve follows a zigzag path of rising and falling values and behaves in a normal manner. The Sm-N and N-I transition curves of a phase diagram behave in the normal established manner except for a small deviation for the higher homologues (C14 and C16). An odd-even effect is exhibited by Sm-N and N-I transition curves. Analytical spectral and thermal data support the molecular structures. Smectic and nematic thermal stabilities are 93.62°C and 114.3°C, respectively. Smectic and nematic mesophas elengths range from 12.0°C to 18.0°C and 11.0°C to 31.0°C. The series is predominantly nematogenic and partly smectogenic and of middle order melting type. Group efficiency order derived for smectic and nematic. Smectic and nematic: ?OCH3 > ?OC4H9 > ?OC7H15(n).
- Jain,Jadeja,Patel
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- Synthesis and properties of 4-[(E)-(4'-R-phenyl)diazenyl]phthalonitriles and cobalt phthalocyanines obtained therefrom
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The diazotization-azocoupling method has been utilized to prepare a series of previously unknown 4-[(E)-(4'-R-phenyl)diazenyl]phthalonitriles, which were further transformed into the corresponding cobalt phthalocyanines. The effect of the peripheral substitution of the phthalocyanine ligand on the spectral properties of the prepared compounds has been demonstrated.
- Tikhomirova,Gruzdeva,Shaposhnikov
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p. 2778 - 2785
(2016/02/18)
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- Synthesis, crystal structure and DFT studies of N-[4-(Heptyloxy)phenyl]-4-methylpyrimidin-2-amine
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The compound N-[4-(heptyloxy)phenyl]-4-methylpyrimidin-2-amine with the molecular formula C18H25N3O was synthesized and recrystallized from CH3OH. The compound was characterized by 1H NMR, MS, HRMS and X-ray diffraction. The compound crystallized in the monoclinic space group P2(1)/c with a = 9.426 (2), b = 14.434 (3), c = 12.884 (3) ?, α = 90, β = 93.779 (3), γ = 90°, V = 1749.2 (6) ?3, Z = 4 and R = 0.0402 for 1798 observed reflections with I > 2σ(I). Theoretical calculation of the title compound was carried out with B3LYP/6-31G (d, p). The full geometry optimization was carried out using 6-31G (d, p) basis set and the frontier orbital energy. The optimized geometric bond lengths and bond angles obtained by using DFT(B3LYP) show the best agreement with the experimental data.
- Wu, Lei-Ting,Sun, Na-Bo,He, Fang-Yue
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p. 7397 - 7400
(2015/04/22)
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- Liquid-crystalline polymorphism of 4-heptyloxybenzylidene-4′- alkyloxyanilines and their phase equilibrium with 4-octyloxyphenyl 4-nitrobenzoate
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This paper describes the synthesis and liquid-crystalline properties of the homologous series of 4-heptyloxybenzylidene-4′-alkyloxyanilines (7-n). Six of them are presented for the first time. Based on the polarization microscopy (POM and TOA methods) and the calorimetric (DSC) measurements following polymorphism has been detected: nematic, smectic C and smectic I mesophases. The presence of these mesophases was confirmed by the miscibility method, using 4-octyloxyphenyl 4-nitrobenzoate and terephtal-bis (4-butyloaniline) as a mesophase references. Extraordinary results have been found in the mixtures of the investigated compounds with 4-octyloxyphenyl 4-nitrobenzoate; Induced smectic A has been observed, which is connected with very strong intermolecular interactions. Additionally destabilization of nematic and smectic C phases was visible.
- Godzwon, Joanna,Sienkowska, Monika J.,Galewski, Zbigniew
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- Liquid crystalline properties of dimers having o-, m- and p- positional molecular structures
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With the objective to design and synthesis of Schiff's base symmetrical liquid crystal dimmers and to study the effect of molecular structure variation (o-ortho, m-meta, p-para) and change in alkoxy terminal chain length on mesomorphic properties of liquid crystals, We have synthesized Schiff base dimers from dialdehyde derivative containing 2-hydroxy-1,3-dioxypropylene as short spacer with aniline derivatives having different lengths of terminal alkoxy chains (n = 5, 7, 9). The chemical structure of the final products was characterized by proton nuclear magnetic resonance (1H NMR) spectroscopy and fourier transform infrared (FT-IR) spectroscopy. The mesomorphic properties and optical textures of the resultant dimers were characterized by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The existence of smectic A phase transition was confirmed by the observation of batonnets and fan shaped textures in optical microscopy when compound were heated from crystalline phase. All of the dimers of this series, with the exception of 2S5 -ortho, -meta, -para, were thermotropic liquid crystal. The compound 2S9 -meta was monotropic, while the rest were enantiotropic. It was found that the change in terminal alkoxy chain length has pronounced effect on the mesomorphic properties. The temperature range of smectic A phase window widens with increasing alkoxy chain length.
- Park, Joo-Hoon,Choi, Ok-Byung,Lee, Hwan Myung,Lee, Jin-Young,Kim, Sung-Jo,Cha, Eun-Hee,Kim, Dong-Hyun,Ramaraj,So, Bong-Keun,Kim, Kyung-Hwan,Lee, Soo-Min,Yoon, Kuk Ro
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p. 1647 - 1652
(2012/07/27)
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- An approach for differentiating isozymes. Construction of libraries containing short aromatic peptides as part of a method to design selective inhibitors against lipases
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Through synthesis and assays of peptidyl substrates, we could select substrates having peptidyl complementary against lipases. The best substrate showed 20-fold improved Km relative to non-peptidyl substrate. Using this information, we generated selective inhibitors. Lipase activities with peptidyl substrates were represented as fingerprints. Differences in fingerprints reflect different structures near active site of lipases, could be used for generating selective inhibitors.
- Park, Sangeun,Yu, Jaehoon
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supporting information; experimental part
p. 3147 - 3151
(2012/06/04)
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- Electro-optical switching studies on 1,3-phenylene based banana shaped liquid crystals
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This work deals with the study of the thermotropic liquid crystalline properties of new asymmetric bent core liquid crystals. The thermotropic properties was analyzed by polarized optical microscopy, differential scanning calorimetric analysis and variable temperature X-ray diffraction measurements. Effect of equal terminal chain with asymmetric bent core system on mesomorphic behavior was examined. The shorter methyl chain compound 10a of exhibits B 1 mesophase and higher homologs (10b and 10c) shows antiferroelectric B2 mesophases, which was studied by electro-optical measurements.
- Balamurugan,Kannan,Yadupati,Roy
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experimental part
p. 118 - 124
(2011/10/03)
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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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- Synthesis and evaluation of alkoxy-phenylamides and alkoxy-phenylimidazoles as potent sphingosine-1-phosphate receptor subtype-1 agonists
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In the design of potent and selective sphingosine-1-phosphate receptor agonists, we were able to identify two series of molecules based on phenylamide and phenylimidazole analogs of FTY-720. Several designed molecules in these scaffolds have demonstrated selectivity for S1P receptor subtype 1 versus 3 and excellent in vivo activity in mouse. Two molecules PPI-4621 (4b) and PPI-4691 (10a), demonstrated dose responsive lymphopenia, when administered orally.
- Evindar, Ghotas,Bernier, Sylvie G.,Kavarana, Malcolm J.,Doyle, Elisabeth,Lorusso, Jeanine,Kelley, Michael S.,Halley, Keith,Hutchings, Amy,Wright, Albion D.,Saha, Ashis K.,Hannig, Gerhard,Morgan, Barry A.,Westlin, William F.
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body text
p. 369 - 372
(2011/03/18)
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- Synthesis of symmetric liquid crystal dimers based on azo and imine groups and investigation of phase behaviour by varying alkoxy terminal chain length
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With the objective to study the effect of alkoxy terminal chain length on mesomorphic properties of liquid crystals, we have synthesized two (Azo and Imine) different series of dimesogens by varying terminal alkoxy chain length (n = 6-12) with a short spacer unit in between two mesogens. Transition temperatures and phase characterization were studied by DSC, POM and XRD analysis. It was found that all the dimers show mesomorphic properties and the change in terminal alkoxy chain length has pronounced effect on the smectic phase window. In the DSC cooling scan, the smectic phase window of azo compounds increased from 6.4°C (2A6) to 16.0°C(2A12), whereas in Schiff base compounds, it increased from 9.2°C (2S6) to 31.0°C(2S12). Further, the 2A11 dimer was found to undergo photo induced configurational changes.
- Kim, Tae Hyeong,Lee, Chang Sin,Ramaraj,Jeon, Hye Jin,Song, Hyun Hoon,Lee, Soo Min,Yoon, Kuk Ro
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experimental part
p. 102 - 116
(2010/03/04)
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- Synthesis and liquid crystalline properties of novel triazene-1-oxide derivatives
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A new group of compounds, C6H5-N(O)=N-NH-C6H4-C(O)-O-C6H4-CH=N-C6H4-OR, (1), [R=n-alkyl group; 1a (R=C7H15 ) to 1h (R=C14H29)], has been designed and synthesized to develop triazene-1-oxide based liquid crystals. All the compounds have been characterized on the basis of their spectral data. Their thermal behavior has been examined and found to exhibit thermotropic liquid crystalline behavior over a wide range of temperature. All members of this family uniformly show nematic phase behavior on melting up to the clearing point during heating as well as on phase entering up to the solidification during cooling. An odd-even effect on transition temperatures has been observed during heating as well as cooling.
- Das, Purak,Biswas, Achintesh Narayan,Bandyopadhyay, Pinaki,Mandal, Pradip Kumar
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scheme or table
p. 3 - 15
(2010/03/24)
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- Smectic polymorphism of 4-nonyloxybenzylidene-4′-alkyloxyanilines
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This paper describes liquid-crystalline polymorphism of the homologous series of 4-nonyloxybenzylidene-4′-alkyloxyanilines. Based on the polarization microscopy (POM, TOA) and the calorimetric (DSC) measurements the following mesophases were detected: nematic, smectic A, smectic C, smectic B, smectic I and smectic G. The presence of these mesophases was confirmed by the miscibility method, using: 4-heptyloxybenzilidene-4′-pentylaniline, 4-hexyl-4′-decyloxyazobenzene and 4-nonyloxybenzilidene-4′-butylaniline as mesophase references. Influence of the alkyl chain length on the type of mesophases and entropic effects of phase transition are discussed.
- Godzwon, Joanna,Sienkowska, Monika J.,Galewski, Zbigniew
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p. 259 - 267
(2008/03/13)
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- METHODS AND COMPOSITIONS FOR MODULATING SPHINGOSINE-1-PHOSPHATE (S1P) RECEPTOR ACTIVITY
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The present invention relates to compounds which modulate the activity of the SI P1 receptor, the use of these compounds for treating conditions associated with signaling through the S1 P1 receptor, and pharmaceutical compositions comprising these compounds.
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Page/Page column 53-54
(2010/10/20)
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- Organosoluble copper clusters as precatalysts for carbon - Heteroelement bond-forming reactions: Microwave and conventional heating
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(Chemical Equation Presented). The coupling of aryl iodides with alcohols under mild conditions has been explored using self-assembled octanuclear copper clusters as catalysts. Reactions involving tetrahydrofurfuryl alcohol were typically complete in 4-8
- Manbeck, Gerald F.,Lipman, Adam J.,Stockland Jr., Robert A.,Freidl, Adrienne L.,Hasler, Amy F.,Stone, Joshua J.,Guzei, Ilia A.
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p. 244 - 250
(2007/10/03)
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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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- Mesogenic 4-(2,3-Epoxypropoxy)-4'-alkoxyazoxybenzenes
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Optimal conditions for preparation of 4-(2,3-epoxypropoxy)-4'-alkoxyazoxybenzenes were developed, and 10 mesogenic homologs (n = 1-10) possessing an extended nematic mesophase were synthesized.Nonyloxy and decyloxy derivatives of epoxyazoxybenzene exhibit also smectic mesomorphism.
- Burmistrov, V. A.,Kuz'mina, S. A.,Koifman, O. I.
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p. 351 - 353
(2007/10/03)
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