• Title/Summary/Keyword: conjugated double bond

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Identification of Fatty Acids in the Oils of Pine Nuts by GC-MS of Their Picolinyl Esters and 4,4-dimethyloxazoline Derivatives in Combination with Silver-Ion Chromatography

  • Kim, Seong-Jin;Woo, Hyo-Kyeng;Seo, Min-Young;Joh, Yong-Goe
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.3
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    • pp.222-244
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    • 2002
  • A mixture of methyl ester derivatives of fatty acids from the oils of pine nuts was well resolved to five fractions differing by degree of unsaturation by silver ion solid-phase extraction column chromatography ($Ag^{+}$-SEC). Polyunsaturated fatty acid with non-methylene interrupted conjugated double bond (NMiDB) radical held more strongly to silver ions in the column than methylene interrupted conjugated double bond (MiDB) one when they had the same number of double bonds. Although both the picolinyl ester and DMOX derivative provided clear mass ion species powerful enough to elucidate the structure of the polyunsaturated fatty acid (PUFA) with NMiDB and/or methylene interrupted conjugated double bond (MiDB) radical in the oils, the picolinyl ester of PUFA with NMiDB radical did not provide a cluster of mass ions neighboring diagnostic mass ions induced by the double bond in the proximal to the carboxyl group. However, the DMOX derivative of PUFA with NMiDB group as well as MiDB showed abundant mass ion species differing by gaps of 12 amu, which made it possible with greater ease to locate the double bonds in the molecule. The oil contained $C_{18:2{\omega}6}$ (46.2 %) and $C_{18:1{\omega}9}$ (25.4 %) as main components, and considerable amounts of PUFAs with NMiDB radical such as ${\Delta}^{5.\;9.\;12}-C_{18:3}$ (16.0 %), ${\Delta}^{5.\;9}-C_{18:2}$ (2.3 %) and ${\Delta}^{5.\;11.\;14}-C_{20:3}$ (0.8 %).

Study on the Thermal Properties of Epoxy Resin Compositions having Conjugated Double Bond in Backbone (공액이중결합의 골격구조를 갖는 에폭시수지 경화물의 열특성에 관한 연구)

  • Lee, KyoungEun;Yoo, Min Jae;Kim, Young Chul
    • Journal of Adhesion and Interface
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    • v.14 no.3
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    • pp.135-145
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    • 2013
  • Epoxy resin compositions were studied on the view of self-extinguishing properties without retardant additives and suitability as materials of eco-friendly EMC (Epoxy molding compound). Cured epoxy and phenolic resin composition having conjugated double bond of aromatic structure exhibited self-extinguishing properties and low heat release capacity. In this study, the structure of long conjugated double bond of hetero-atom type azomethyne group between conjugated double bonds of aromatic structure showed lower heat release capacity. Low heat release capacity seemed to be related with high reaction enthalpy, $T_g$ and reactivity affected by hetero-atom structure in azomethyne group.

Effects of Conjugated Double Bond Derivatives of Polyunsaturated Fatty Acid on Serum Lipids in Rats (다가불포화지방산의 공역이중결합 유도체가 흰쥐의 혈청 지질 성분에 미치는 영향)

  • Kim, So-Young;Kim, Sung-Hee;Kim, Gyeong-Eup
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.9
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    • pp.1120-1127
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    • 2007
  • This study was designed to examine the effects of n-6 PUFA rich corn oil, n-3 PUFA rich perilla oil and their conjugated double bond derivatives on serum lipids status in rats. Experimental diets containing lard (control), corn oil (CO), perilla oil (PO), conjugated double bond derivatives of n-6 PUFA rich corn oil (TCO) and n-3 PUFA rich perilla oil (TPO) at the level of 10% (w/w) were fed to male Sprague Dawley rats for 4 weeks. TCO was found to have three derivatives of linoleic acid and TPO had five derivatives of linolenic acid by GC. Serum total cholesterol levels were significantly lower in the all experimental groups than in the control group, and particularly, the lowest in TCO and TPO groups. HDL-cholesterol concentrations were a little higher in the all experimental groups than in the control group, and TCO and TPO groups were not significantly different from CO and PO groups. Serum LDL, LDL-cholesterol, chylomicron and triglyceride concentrations were significantly lower in the all experimental groups than in the control group, remarkably lower in TCO group and particularly, the lowest in the TPO group. Serum free cholesterol and cholesteryl ester concentrations were lower in TCO and TPO groups than in CO and PO groups. From the above research, TCO and TPO groups were effective on the improvement of the lipid compositions in serum and particularly, TPO group was the most effective on the improvement of serum lipids.

Structural Studies on Conjugated Oximes (II). Nuclear Magnetic Resonance spectral Analysis on the Configuration and Hydrogen Bond of cis-2-Butenedialdioxime in Solutions (Conjugated Oxime의 立體構造에 關한 硏究 (第2報). NMR에 依한 cis-2-Butenedialdioxime의 Configuration 및 水素結合에 對한 考察)

  • Hong Young-Suek;Lee Hak-Ki
    • Journal of the Korean Chemical Society
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    • v.19 no.4
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    • pp.233-239
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    • 1975
  • The configuration of two oxime groups in cis-2-butenedialdioxime, unsymmetrical compound conjugated by three double bonds, is determined by a NMR study on the effects of the solvent, temperature and concentration; it is certain that, in solutions of usual conditions, the configuration exists as only "syn-syn". And the relative strengths of the hydrogen bond between these oxime groups and several solvents are compared and somc effects of the temperature and concentration are also considered. The several models of hydrogen bond between oxime and solvents are proposed; especially it is to be noted here that the hydrogen bond in pyridine solvent is not resulted from the interaction between a lone electron pair on nitrogen atom of pyridine and the hydroxyl proton of oxime, but the result of $\pi$-complex formed between the $\pi$-orbital of pyridine and the hydroxyl proton of the solute.

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Effects of Zeolites on Thermal Stability of Poly(vinyl chloride) (폴리염화비닐(PVC)의 열안정성에 제올라이트가 미치는 영향)

  • Xu, Jiayou;Liang, Qinghua;Xian, Xiumei;Li, Kaidan;Liu, Jie
    • Polymer(Korea)
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    • v.39 no.1
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    • pp.1-5
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    • 2015
  • The effects of zeolite on the thermal stability of poly(vinyl chloride) (PVC) were investigated by the static thermal stability test, pyrolysis experiment and ultraviolet spectrum. The results showed that the porous zeolite could absorb hydrogen chloride (HCl), which suppressed the catalysis of HCl on thermal degradation of PVC, thus improved the thermal stability of PVC. The oxidizing acid which was loaded on zeolite had oxidated on the double bond that formed during the dehydrochlorination of PVC. This process could prohibit the growth of the conjugated polyene and improved the color of PVC. Hence, zeolite might be possible to come up with a high performance thermal stabilizer.

Structural Studies on Conjugated Oximes (Ⅲ). The Conformational Study of cis-2-Butenediadioxime by EHT (Conjugated Oxime 의 立體構造에 關한 硏究 (第3報). EHT 에 依한 cis-2-Butenedialdioxime 의 形態決定)

  • Hong Young-Suek;Park Byung-Kack
    • Journal of the Korean Chemical Society
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    • v.20 no.6
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    • pp.507-513
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    • 1976
  • Conformation of cis-2-butenedialdioxime, a newly synthesized compound, was assigned by means of nuclearmagnetic resonance, extended Huckel molecular orbital method, and Pople's model of anisotropic effect. It was confirmed that two carbon-carbon single bonds are conrotatorily twisted from the molecular plane of six $sp^2$ orbitals of carbon-carbon double bond. The conformation of minimum energy is found to be twisted by$25^{\circ}C.$

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PHOTOISOMERIZATION STUDIES OF SUBSTITUTED DIPHENYLBUTADIENES: ROLE OF POLARIZED EXCITED STATES IN THE PHOTOPROCESSES OF $\alpha,\omega$-DIPHENYLPOLYENES

  • Singh, A.K.;Krishna, T.S.R.
    • Journal of Photoscience
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    • v.5 no.2
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    • pp.47-51
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    • 1998
  • Direct irradiation of 1Z,3E-1-cyano-1,4-diphenylbutadiene (2) and 1Z,3E-1-cyano-3-methyl-1,4-diphenylbutadiene (3) in organic solvents viz. n-hexane, methanol and acetonitrile results in preferential isomerization of the double bond substituted with cyano group via one-photon-one-bond isomerization process. The quantum efficiency of the isomerization of 3 is more than 2 in all the three solvents. Photoproducts of 2 and 3 (viz. 2a, 2b, 3a, 3b) also exhibited similar photoisomerization trends. The results are discussed in terms of the effects of substituents on the potential energy surface of the excited singlet states of $\alpha$,$\omega$-diphenylpolyenes, and the role of zwitterionic dipolar species in the photoisomerization process of linearly conjugated C=C polyenes is highlighted.

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Cross Conjugated Chromophores Based On Indigo Typed

  • Park, Su-Yeol;Jeon, Geun;Sin, Jong-Il;Sin, Seung-Rim;O, Se-Hwa
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2004.11a
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    • pp.274-275
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    • 2004
  • The majority of dyes belong to the chromophoric class known as donor-acceptor systems, the essential structural feature of such systems being the presence of one or more electron donating groups conjugated to one or more electron withdrawing groups via an unsaturated bridge. The indigo molecule may be formally divided into two identical electron donor/acceptor subsystems, each containing an add number of pi electrons, two subsystems being joined by carbon-carbon double bond. Indigoid type dyes which show a strong colour change on protonation or dissociation have many potential functional applications, for example as analytical pH indicators, solvent polarity indicators, and in various imaging and reprographic systems.

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Synthesis and Fragmentation of Furoxanaldehydes in the Gas Phase for Nanopatterned Alkyne Formation on a Solid Surface

  • Kim, Gi-Young;Kim, Ju-Cheon;Lee, Seung-Hee;Kim, Hyung-Jin;Hwang, Kwang-Jin
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.459-463
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    • 2009
  • Furoxanaldehydes possessing phenyl or alkenyl groups at the 3- or 4-position of the furoxan ring were designed for alkyne formation on a solid surface. Furoxans 2 and 3 were prepared from the corresponding alkenes 2a and 3a by the reaction with NaN$O_2$ in acetic acid. Furoxan 4, in which the furoxan ring is conjugated with a double bond, was prepared from bis(bromomethyl)benzene 4a in 5 steps using the Wittig reaction of aldehyde 1 as the key step. The electron beam-mediated fragmentation of furoxanaldehydes 1-4 in a mass spectrometer was exploited by focusing on alkyne formation on the solid surface. The fragmentation of furoxan 3 possessing diaryl groups afforded diarylacetylene at high efficiency, suggesting that the aryl group conjugated with the furoxan ring could facilitate alkyne formation with the evolution of NO.

Synthesis and Properties of Poly[4,4-bis(acetoxymethyl)-1,6-heptadiyne]

  • Kim, Yun-Hi
    • Bulletin of the Korean Chemical Society
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    • v.18 no.1
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    • pp.66-70
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    • 1997
  • The polymerization of 4, 4-bis(acetoxymethyl)-1, 6-heptadiyne (BAH) was carried out by MoCl5 and WCl6 with various organometallic cocatalysts. MoCl5-based catalysts were more effective than WCl6-based ones for the cyclopolymerization of BAH. Poly(BAH) was characterized to have polymer backbone with conjugated double bond and cyclic structure by IR, UV-visible, and 1H-and 13C NMR spectroscopies. The polymer was stable up to 310 ℃ and 5 % weight loss show up at 350 ℃. The resulting dark violet polymer exhibited good solubility in common organic solvents and could be cast on a glass plate to give film with good mechanical properties. It was found that oxygen permeability (PO2) and permselectivity (PO2/PN2) of the resulting polymer were 15.2 barrer and 2.84, respectively.