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Myung Ho Hyun - One of the best experts on this subject based on the ideXlab platform.
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Preparation of Two New Diasteromeric Chiral Stationary Phases Based on (+)-(18-Crown-6)-2,3,11,12-Tetracarboxylic Acid and (R)- or (S)-1-(1-Naphthyl)ethylamine and Chiral Tethering Group Effect on the Chiral Recognition.
Molecules (Basel Switzerland), 2016Co-Authors: Rajalingam Agneeswari, Ji Yeong Sung, Hee Young Jeon, Vellaiappillai Tamilavan, Myung Ho HyunAbstract:Two new diastereomeric chiral stationary phases (CSPs) based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid as a chiral tethering group and a Π-basic chiral unit such as (R)-1-(1-naphthyl)ethylamine (CSP 1) or (S)-1-(1-naphthyl)ethylamine (CSP 2) were prepared. The two CSPs were applied to the enantiomeric separation of N-(3,5-dinitrobenzoyl)-1-phenylalkylamines and N-(3,5-dinitrobenzoyl)-α-amino Acid derivatives using 20% isopropyl alcohol in hexane as a normal mobile phase. To elucidate the effect of the two chiral units on the chiral recognition, the chiral recognition abilities of the two CSPs were compared with each other and with that of a CSP (CSP 3) based on (R)-1-(1-naphthyl)ethylamine. From the chromatographic chiral recognition results, (R)-1-(1-naphthyl)ethylamine and (+)−(18-crown-6)-2,3,11,12-Tetracarboxylic Acid constituting CSP 1 were concluded to show a cooperative (“matched”) effect on the chiral recognition while (S)-1-(1-naphthyl)ethylamine and (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid constituting CSP 2 were concluded to show an uncooperative (“mismatched”) effect on the chiral recognition. From these results, it was concluded that (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid can be successfully used as a chiral tethering group for the preparation of new CSPs.
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Development of HPLC Chiral Stationary Phases Based on (+)-(18-Crown-6)-2,3,11,12-Tetracarboxylic Acid and Their Applications.
Chirality, 2015Co-Authors: Myung Ho HyunAbstract:Crown ether-based chiral stationary phases (CSPs) have been known to be useful for the resolution of racemic primary amino compounds. In particular, CSPs based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid have been reported to be useful for the resolution of secondary amino compounds as well as primary amino compounds. In this article, the process of developing various CSPs based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid to improve the chiral recognition efficiency and/or the stability of the CSPs and their applications to the resolution of various primary and nonprimary amino compounds are reviewed. Chirality 27:576–588, 2015. © 2015 Wiley Periodicals, Inc.
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Enantioseparation of α-amino Acids on an 18-crown-6-Tetracarboxylic Acid-bonded silica by capillary electrochromatography
Journal of chromatography. A, 2010Co-Authors: Taeho Lee, Myung Ho Hyun, Wonjae Lee, Jung Hag ParkAbstract:(-)-(18-Crown-6)-2,3,11,12-Tetracarboxylic Acid-bonded silica was used as the chiral stationary phase in capillary electrochromatography (CEC) for enantioseparation of some alpha-amino Acids. Separation data in CEC were measured in mobile phases of varying pH, and composition of methanol and buffer, and compared with those in capillary liquid chromatography (CLC). In CEC better enantioseparation was generally obtained in the eluent of lower pH, higher buffer concentration and intermediate MeOH content, usually at the expense of analysis time. CEC showed generally better enantioselectivity and resolutions than CLC for the amino Acids investigated.
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high performance liquid chromatographic enantioseparation of β amino Acid stereoisomers on a 18 crown 6 2 3 11 12 Tetracarboxylic Acid based chiral stationary phase
Journal of Chromatography A, 2006Co-Authors: Robert Berkecz, Myung Ho Hyun, Enikő Forró, Ferenc Fülöp, Anita Sztojkovivanov, Istvan Ilisz, Antal PeterAbstract:Direct reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of 14 unnatural β-amino Acids, including several β-3-homo-amino Acids on a chiral stationary phase containing (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid bonded to 3-aminopropyl silica gel as chiral selector. The effects of the organic and the Acidic modifiers and the mobile phase composition on the separation were investigated. The natures and positions of the substituents on the aromatic ring substantially influenced the retention and enantioseparation. The elution sequence in most cases was determined and the R enantiomers were eluteted before the S enantiomers.
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preparation and application of hplc chiral stationary phases based on 18 crown 6 2 3 11 12 Tetracarboxylic Acid
IEEE Journal of Solid-state Circuits, 2006Co-Authors: Myung Ho HyunAbstract:Preparation of liquid chromatographic chiral stationary phases (CSPs) based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid and their application are reviewed. The various methods of connecting (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid to silica gel covalently or dynamically are demonstrated. The CSPs based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid have been very successful for the resolution of various primary amino compounds with the use of an aqueous mobile phase containing organic and Acidic modifiers. In addition, the resolution of secondary amino compounds including beta-blockers and N-(3,5-dinitrobenzoyl)-alpha-amino Acids has been demonstrated on a CSP based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid with a non-aqueous mobile phase.
Dian Zhao - One of the best experts on this subject based on the ideXlab platform.
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synthesis structure and temperature sensing of a lanthanide organic framework constructed from a pyridine containing Tetracarboxylic Acid ligand
CrystEngComm, 2018Co-Authors: Dian Zhao, Huizhen Wang, Guodong QianAbstract:The ongoing need for accurate measurement of temperature in microelectronic diagnosis is driving the development of novel temperature sensors. In this work, we synthesized a Tetracarboxylic Acid ligand containing a pyridine moiety to construct a three-dimensional lanthanide MOF EuPDDI (H4PDDI = 5,5′-(pyridine-2,5-diyl)diisophthalic Acid). Thermal analysis shows the favourable thermal stability of the main framework of EuPDDI up to 380 °C. By Eu3+ and Tb3+ co-doping, a mixed LnMOF thermometer Eu0.19Tb0.81PDDI, effective in the temperature range of 313 to 473 K, was obtained. Its features include high relative sensitivity, and accurate temperature resolution. Such a LnMOF is useful for temperature sensing and diagnosis in microelectronics.
Li Ya Wang - One of the best experts on this subject based on the ideXlab platform.
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five mn ii coordination polymers based on 2 3 5 5 biphenyl Tetracarboxylic Acid syntheses structures and magnetic properties
Crystal Growth & Design, 2015Co-Authors: Ying Zhao, Xinhong Chang, Guangzhen Liu, Li Ya WangAbstract:Five manganese(II) coordination polymers with 2,3′,5,5′-biphenyl Tetracarboxylic Acid (H4bptc) and five N-donor ancillary ligands, {[Mn2(bptc)(2,2′-bipy)2]·2H2O}n (1), {[Mn2(H2bptc)2(phen)4]·6H2O} (2), {[Mn3(Hbptc)2(4,4′-bipy)4(H2O)4]·4H2O}n (3), {[Mn2(bptc)(1,4-biyb)2]}n (4), and {[Mn3(Hbptc)2(biip)2(H2O)2]}n (5) [2,2′-bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, 4,4′-bipy = 4,4′-bipyridine, 1,4-biyb = 1,4-bis(imidazol-1-ylmethyl)benzene, biip = 3,5-bis(1-imidazol)pyridine], have been synthesized under hydrothermal conditions. Complexes 1–5 were structurally characterized by elemental analysis, infrared (IR) spectra, X-ray single-crystal diffraction, and powder X-ray diffraction (PXRD). Complex 1 exhibits a 2D layered structure with a (3,6)-connected (43)2(46.66.83) topology. Complex 2 shows a 0D structure and further stacks via hydrogen-bonding interactions to give a 3D supramolecular architecture. Complex 3 possesses a 3D structure with a 4-connected (4.63.82)(44.62)(43.63) topology. Complex 4 d...
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Two unique lanthanide–organic frameworks based on biphenyl-2,3,3′,5′-Tetracarboxylic Acid: Syntheses, crystal structures and luminescence properties
Polyhedron, 2015Co-Authors: Xin Fang Liu, Tian Zhang, Li Ya Wang, Xun FengAbstract:Abstract The reactions in mixtures of lanthanide oxides and biphenyl-2,3,3′,5′-Tetracarboxylic Acid, in the presence of aqueous solution, result in two interesting lanthanide–organic coordination polymers, formulated as{[Eu(Hbptc)(H2O)4]·H2O}n (1) and [Sm(Hbptc)(H2O)3]}n (2), (H4bptc = biphenyl-2,3,3′,5′-Tetracarboxylic Acid). The polymers 1 and 2 are built from 2D corrugated layer. The 2D layers are further interconnected to form the 3D framework by hydrogen bonds between water molecules and carboxyl groups. Both the complexes 1 and 2 exhibit efficient sensitized luminescence in the visible region in the solid state based on characterization emission of europium(III) and samarium(III) ions, respectively.
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Synthesis and Crystal Structure of a Novel Tetrahydrofuran-2,3,4,5-Tetracarboxylic Acid-bridged Manganese (II) Polymer with 2-D Structure
Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry, 2008Co-Authors: Li Ya Wang, Fan ZhongAbstract:First tetrahydrofuran-2,3,4,5-Tetracarboxylic Acid-bridged manganese(II) coordination polymer [Mn2L]n(L = tetrahy- drofuran-2,3,4,5-Tetracarboxylic Acid tetraanion) has been synthesized and characterized structurally. It crystallizes in the monoclinic space group P21/c. a = 14.9418(15)A, b = 7.7340(8) A, c = 10.7222(11) A, β = 102.59(10)•. Both of the Mn (II) ions in the complex are six-coordinated with a distorted octahedral geometry, but the coordination environments for them are different. For every ligand, all of the oxygen atoms are participating in coordinating. The complex displays a two-dimensional polymer through coordination bonds.
Akinari Sonoda - One of the best experts on this subject based on the ideXlab platform.
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liquid crystalline perylene Tetracarboxylic Acid bisimide bearing oligosiloxane chains with high electron mobility and solubility
Organic Electronics, 2012Co-Authors: Masahiro Funahashi, Akinari SonodaAbstract:Abstract Liquid–crystalline perylene Tetracarboxylic Acid bisimide derivatives 1 and 2 bearing 1,1,1,2,2,3,3-heptamethyltrisiloxane chains at the end of alkyl side-chains have been synthesized. Compound 1 having four trisiloxane chains exhibits a hexagonal columnar phase at room temperature. Time-of-flight measurement reveals that the electron mobility in the columnar phase of compound 1 exceeds 10−3 cm2 V−1 s−1 at room temperature. In contrast, compound 2 bearing two trisiloxane chains is not mesomorphic. These two compounds are soluble in various organic solvents except for alcohols and thin films can be produced by a spin-coating method.
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Liquid–crystalline perylene Tetracarboxylic Acid bisimide bearing oligosiloxane chains with high electron mobility and solubility
Organic Electronics, 2012Co-Authors: Masahiro Funahashi, Akinari SonodaAbstract:Abstract Liquid–crystalline perylene Tetracarboxylic Acid bisimide derivatives 1 and 2 bearing 1,1,1,2,2,3,3-heptamethyltrisiloxane chains at the end of alkyl side-chains have been synthesized. Compound 1 having four trisiloxane chains exhibits a hexagonal columnar phase at room temperature. Time-of-flight measurement reveals that the electron mobility in the columnar phase of compound 1 exceeds 10−3 cm2 V−1 s−1 at room temperature. In contrast, compound 2 bearing two trisiloxane chains is not mesomorphic. These two compounds are soluble in various organic solvents except for alcohols and thin films can be produced by a spin-coating method.
Dandan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Resolution of beta-blockers on a chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid: unusual temperature effect.
Journal of chromatography. A, 2005Co-Authors: Dandan Zhang, Hee Jung Choi, Do Hun Kim, Myung Ho HyunAbstract:A chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid has been successfully employed in the liquid chromatographic resolution of eleven beta-blockers containing a secondary amino functional group. As the result of an effort to find out the optimal mobile phase condition, the mixture of trifluoroacetic Acid-triethylamine-ethanol-acetonitrile with the ratio of 0.1/0.5/20/80 (v/v/v/v) was concluded to be the best mobile phase condition, the separation (alpha) and the resolution factors (Rs) for the resolution of 11 beta-blockers being in the range of 1.13-1.85 and 1.36-5.79, respectively. Surprisingly, in contrast to the resolution of other racemic compounds containing a primary amino functional group, the separation factors (alpha) for the resolution of beta-blockers were observed to improve as the column temperature increased and these unusual chromatographic behaviors were rationalized as the entropically controlled enantioselectivity.
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Resolution of β-blockers on a chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid: Unusual temperature effect
Journal of Chromatography A, 2005Co-Authors: Dandan Zhang, Hun Kim, Hee Jung Choi, Myung Ho HyunAbstract:Abstract A chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-Tetracarboxylic Acid has been successfully employed in the liquid chromatographic resolution of eleven β-blockers containing a secondary amino functional group. As the result of an effort to find out the optimal mobile phase condition, the mixture of trifluoroacetic Acid–triethylamine–ethanol–acetonitrile with the ratio of 0.1/0.5/20/80 (v/v/v/v) was concluded to be the best mobile phase condition, the separation (α) and the resolution factors (RS) for the resolution of 11 β-blockers being in the range of 1.13–1.85 and 1.36–5.79, respectively. Surprisingly, in contrast to the resolution of other racemic compounds containing a primary amino functional group, the separation factors (α) for the resolution of β-blockers were observed to improve as the column temperature increased and these unusual chromatographic behaviors were rationalized as the entropically controlled enantioselectivity.
