• Title/Summary/Keyword: tris

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Transformation of Carboxylic Acids and Their Derivatives into Aldehydes by Lithium Tris(dialkylamino)aluminum Hydrides

  • Cha Jin Soon
    • Bulletin of the Korean Chemical Society
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    • v.13 no.6
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    • pp.670-676
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    • 1992

  • A systematic study of the partial reduction of carboxylic acids and their derivatives to the corresponding aldehydes with lithium tris(dialkylamino)aluminum hydrides under practical conditions has been carried out. The diethylaminosubstituted derivative of lithium aluminum hydride, lithium tris(diethylamino)aluminum hydride (LTDEA), shows quite general applicability in the conversion of carboxylic acids, carboxylic esters, and primary carboxamides to the corresponding aldehydes. Lithium tripiperidinoaluminum hydride (LTPDA) also appears to be a reagent of choice for such partial transformation of primary carboxamides. In additioin, both LTDEA and LTPDA reduce tertiary carboxyamides to aldehydes in high yields. Finally, lithium tris(dihexylamino)aluminum hydride (LTDHA) is capable of achieving the chemoselective reduction of aromatic nitriles to aldehydes in the presence of aliphatic nitriles under practical conditions.

  • https://doi.org/10.5012/bkcs.1992.13.6.670 인용 PDF

Photoluminescence properties of eight coordinated terbium(III) complexes (8배위 터븀 (III) 착화합물의 합성과 Photoluminescence 특성)

  • Yun, Myung-Hee;Kim, Yeon-Hee;Choi, Won-Jong;Chang, Choo-Hwan;Choi, Seong-Ho
    • Analytical Science and Technology
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    • v.24 no.6
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    • pp.451-459
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    • 2011

  • Eight coordinated terbium(III) complexes, tris (2-pyrazinecarboxylato)(phenanthroline) terbium(III) [$Tb(pzc)_3$(phen)], tris (5-methyl-2-pyrazinecarboxylato) (phenanthroline) terbium(III) [$Tb(mpzc)_3$(phen)] and tris(2-picolinato) (phenanthroline) terbium(III) [$Tb(pic)_3$(phen)], have been synthesized and characterized by Fourier transform infrared (FT-IR), UV-Visible and X-ray photoelectron spectroscopy. Photoluminescence (PL) spectroscopy shows that these complexes emitted strong green luminescence. When powder samples of the $Tb^{3+}$ complexes are examined using time-resolved spectroscopic analysis, the luminescence lifetimes are found to be 0.87 ms and 1.0 ms, respectively. Thermogravimetric analysis reveals the terbium complexes to have good thermal stability up to $333-379^{\circ}C$. Cyclic voltammetry shows that HOMO-LUMO energy gap of the $Tb^{3+}$ complexes ranges from 4.26~4.41 eV. These values are similar to those obtained from the UV-visible spectra. Overall, the synthesized $Tb^{3+}$ complexes may be useful advanced materials for green light emitting devices.

  • https://doi.org/10.5806/AST.2011.24.6.451 인용 PDF KSCI

A Comparative Study on the Extenders for Freezing Canine Semen (개 동결정액을 위한 희석액의 비교연구)

  • Kim Heui-Eun;Lee Jung-won;Kim Nam-Soo;Choi In-Hyuk
    • Journal of Veterinary Clinics
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    • v.10 no.1
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    • pp.11-18
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    • 1993

  • Four extenders such as tris-fructose-citrate, Tris-glucose-citrate, glycine-glucose-citrate and lactose that the more frequently utilized types of semen extenders used for freezing dog semen evaluated with sperm motility, viability and acrosomal score in the processing procedures to prior freezing and after frozen-thawing respectively. Each extender contained 4% glycerol and 20% egg yolk were treated by same methods in dilution, freezing, storage and thawing. The results were obtained as follows; 1. The sperm motility and viability in procedure from dilution to frozen-thawing appeared superiorly with recovery rate of 53.2%, 54.8% in tris-fructose-citrate but appeared inferiorly with recover rate of 8.4%, 8.3% in lactose to others. 2. In the processing procedure course to prior-freezing, glycine-glucose-citrate appeared superiorly with decrease rate of 5.4% in motility, and lactose with decrease rate of 4.6% in viability, but tris-glucose-citrate appeared inferiorly with decrease rate of 12.2%, 11.4% in the sperm motility and viability. 3. During frozen-thawing, tris-fructose-citrate appeared superiorly with decrease rate of 35.2% in motility and 30.7% in viability but lactose appeared inferiorly with decrease rate of 76.7% in motility and 75.7% in viability. 4. The variation of acrosome morphology in the total processing procedures appeared that glycine-glucose citrate were superior with acrosome score of 0.1191$\pm$0.029, that tris-fructose-citrate were inferior with acrosome score of 0.1941$\pm$0.045 to others.

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