• 제목/요약/키워드: complex formation

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Studies on the Organic Base Complexes and their Application to Analytical Chemistry. I. A Study on the Formation of Chlorpromazine Bromothymol Blue Complex and its Application to Analytical Chemistry. (4 유기염기착화합물의 분석화학적연구 I. Chlorpromazine Bromthymol Blue Complex 의 분석화학적연구)

  • 김차덕;심상혁;서정현
    • YAKHAK HOEJI
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    • 제9권1_2호
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    • pp.14-17
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    • 1965
  • It has been known that the organic base complexes formed with the anionic acid base indicators are highly soluble in non-polar solvents but relatively insoluble in water. In the work reported here the formation of the complex between chloropromazine and bromothymol blue was studied and applied it to the determination of the base. The values to determine the binding ratio of the base with the indicator at pH 3.5 obtained from the application of Job's method of continuous variation and mol ratio method were both 1:1. From the application of this reaction to the determination of the base with carbon tetrachloride as the solvent for the extraction, fairy good results have been obtained.

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Ettect of Sodium Gluconate on the Hydration of 3CaO.$Al_2O_3$(I)-Adsorption Behavior- (3CaO.$Al_2O_3$의 수화반응에 미치는 글루콘산나트륨읨 영향(I) -흡착거동-)

  • 김창은;이승헌;유종석;최진호
    • Journal of the Korean Ceramic Society
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    • 제23권2호
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    • pp.38-42
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    • 1986
  • The adsorption behavior of 3CaO.$Al_2O_3$-sodium gluconate-$H_2O$ system by measuring adsorp-tion isotherm DTA and IR sepctra. The adsorbed amount of sodium gluconate on 3CaO.$Al_2O_3$ is exceedingly larger than 3CaO.$SiO_2$ and portland cement. From the DAT experiment the formation of complex is observed by the characteristic exothermic peak of the complex at 45$0^{\circ}C$ It is now strong deduced that the chemical bonding between gluconate anion and 3CaO.$Al_2O_3$ should be coordinative due to the complex formation on the surface 3CaO.$Al_2O_3$ from the IR spectra of sod-ium gluconate only and 3CaO.$Al_2O_3$ -sodium gluconate-$H_2O$.

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SNARE Assembly and Membrane Fusion: A Paramagnetic Electron Magnetic Resonance Study

  • Kweon, Dae-Hyuk
    • Proceedings of the Korean Biophysical Society Conference
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.32-32
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    • 2003
  • In the neuron, SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) assembly plays a central role in driving membrane fusion, a required process for neurotransmitter release. In the cytoplasm, vesicular SNARE VAMP2 (vesicle-associated membrane protein 2) engages with two plasma membrane SNAREs syntaxin 1A and SNAP-25 (synaptosome-associated protein of 25 kDa) to form the core complex that bridges two membranes. While various factors regulate SNARE assembly, the membrane also plays the regulatory role by trapping VAMP2 in the membrane. The fluorescence and EPR analyses revealed that the insertion of seven C-terminal core-forming residues into the membrane controls complex formation of the entire core region, even though preceding 54 core-forming residues are fully exposed and freely moving. When two interfacial Trp residues in this region were replaced with hydrophilic serine residues, the mutation supported rapid complex formation.

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Effects of Borane-Pyridine Complex on Mesophase Formation from Decant Oil

  • Han, Dong-Yun;Moon, Sook-Young;Lim, Yun-Soo
    • Carbon letters
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    • 제5권3호
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    • pp.113-117
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    • 2004
  • The mesophase pitch was prepared by adding 1~10 wt% of the borane-pyridine complex (BPC) to decant oil. It was prepared in a reactor held at $450^{\circ}C$ for 2 h in $N_2$ atmosphere. The mesophase pitches were analyzed using thermogravimetric analyzer (TGA), melting point apparatus, X-ray diffraction (XRD) and polarized optical microscope. The coke yield, softening point, toluene insoluble, density and content of anisotropy in the mesophase pitches were increased with BPC contents. The XRD profiles did not show any effect of addition of BPC on the formation of mesophase pitch, while the crystallinity of mesophase pitches was increased when the materials were heat treated with boron compound.

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Synthesis of High Tc Superconductor YBa2Cu3O7-$\delta$ by Oxalate Coprecipitation Method II. The Effect of Cu2+-Oxalate-Complex Formation for the Solubilities of Y3+ and Ba2+ (Oxalate공침법에 의한 고온 초전도체 YBa2Cu3O7-$\delta$의 합성 II. Cu2+-Oxalate-Complex가 Y3+ 및 Ba2+의 용해도에 미치는 영향)

  • 최진호;김배환;최규원
    • Journal of the Korean Ceramic Society
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    • 제26권3호
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    • pp.395-401
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    • 1989
  • The concentrations of Cu(II), Y(III) and Ba(II) ionic species in aqueous solution due to the formation of Cu2+-oxalate-complex have been theoretically calculated with respect to pH and their solubility diagrams could be obtained. It was verified from the calculation that the excess of Cu2+ and Ba2+ should be added in order to obtain oxalate coprecipitates with the molar ratio of Y : Ba : Cu=1 : 2 : 3. The exact amount of excess species has been calculated with respect to the initial concentrations of metal ions and pH.

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Molecular Conformation-Dependent Complexation between Acidic- and Basic-Polypeptides via Hydrogen Bonding in Solution

  • Jang, Cheon Hak;Kim, Hyeon Don;Jo, Byeong Gi;Lee, Jang U
    • Bulletin of the Korean Chemical Society
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    • 제16권1호
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    • pp.42-47
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    • 1995
  • Interpolymer complex formation between basic polypeptide poly(L-proline) Form Ⅱ (PLP(Ⅱ)) and acidic polypeptides poly(L-glutamic acid) (PLGA) and poly(L-aspartic acid)(PLAA) has been studied in water-methanol (1:2 v/v) mixed-solvent by viscometry, potentiometry, light scattering and circular dichroism (CD) measurements. It has been found that polymer complexes between PLP(Ⅱ) and PLGA (or PLAA) are formed via hydrogen bonding with a stoichiometric ratio of PLP(Ⅱ)/PLGA (or PLAA)=1:2 (in unit mole ratio) and that PLP(Ⅱ) forms polymer complex more favorably with PLGA than with PLAA. In addition, the minimum (for pH 5.0) and the maximum (for pH 3.2) in reduced viscosity of dilute PLP(Ⅱ)-PLGA mixed solutions are observed at 0.67 unit mole fraction of PLGA (i.e., [PLP(Ⅱ)]/[PLGA]=1/2). These findings could be explained in terms of molecular structure (or conformation) of the complementary polymers associated with the complex formation.

Photochemical Studies of Schiff Base Cu(II) Complex: (1) UV-Irradiation of N,$N^{\prime}$-bis(salicylidene)ethylenediamine copper(II)

  • An, Byeong Tae
    • Bulletin of the Korean Chemical Society
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    • 제16권3호
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    • pp.202-204
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    • 1995
  • The ultraviolet photochemistry of N,N'-bis(salicylidene)ethylenediamine copper(II), Cu(sal)2en, was investigated with low pressure mercury lamp. Redution of Cu(Ⅱ) and formation of Cl- were shown on 254 nm irradiation both for aerated and deaerated chlorinated hydrocarbon solvent such as CH2Cl2, chloroform, and 1,2-dichloroethane. Relatively long lived $({\tau}=100{\mu}sec)$ intermediate was detected by flash photolysis. Overall photo-process can be described as the formation of Cl- and new copper complex, product(1) by chlorohydrocarbon mediation, photoinduced reduction by abstraction of halogen from solvent, followed by redox induced substitution of axial ligand with chlorine. Product(1) is possibly Cu(III) chlorosalicylaldeimido complex and cyclic -CH2CH2- moiety is absent in the structure. 247nm band of Cu(sal)2en should contain ligand to metal charge transfer character.

Morphological Characteristics of Thecodiplosis japonensis (Diptera: Cecidomyiidae) Larvae in Pine Forests Around Onsan Industrial Complex in Ulsan, Korea (공단지역 주변 소나무림의 솔잎혹파리 형태적 특성)

  • Lee, Chong-Kyu
    • Korean journal of applied entomology
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    • 제56권1호
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    • pp.77-81
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    • 2017
  • The results from our investigation showed differences in pine needle damage by Thecodiplosis japonensis Uchida et Inouye and indicate serious environmental pollution caused by a petrochemical industrial complex. The gall formation rate by T. japonensis near the industrial complex was 47.94% compared to 9.94% in the site farthest from the complex. The average length of pine needles damaged by T. japonensis near the industrial complex and farthest site were 4.5 cm and 4.9 cm, respectively. The average number of larvae in pine needle galls near the industrial complex and farthest site were 3.4 and 2.4, respectively. The average body length and width of fullgrown larvae near the industrial complex were 2.40 mm and 0.7 mm, respectively, whereas larvae in the site farthest from the complex were 2.45 mm in length and 0.71 mm in width.

Determination of Complex Formation Constant of Sodium-Selective Ionophores in Solvent Polymeric Membranes (용매 고분자막 상에 고정된 나트륨 이온선택성 물질의 착물형성상수 결정)

  • Kang, Tae Young;Kim, Sung Bae;Oh, Hyon Joon;Han, Sang Hyun;Cha, Geun Sig;Nam, Hakhyun
    • Analytical Science and Technology
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    • 제13권4호
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    • pp.466-473
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    • 2000
  • The complex formation constants (${\beta}_{MLn}$) of potassium and various sodium-selective neutral carriers in solvent polymeric membranes have been determined using solvent polymeric membrane-based optodes and ion-selective electrodes (ISEs). Two different types of PVC-based membranes containing the H^+selective chromoionophore (ETH 5294) with and without a sodium ionophore (4-tert-bntylcalix[4]arenetetraacetic acid tetraethyl ester, ETH 2120, bis[(12-crown-4)methyl] dodecylmethylmalonate or monensin methyl ester) were prepared and their optical responses to either the changes in alkali metal cation (e.g., sodium and potassium) concentrations at a fixed pH (0.05 M Tris-HCl, pH 7.2) or varying pH at a fixed alkali metal cation concentration (0.1 M) were measured. The same type of membranes were also mounted in conventional electrode body and their potentiometric responses to varying pH at a fixed alkali metal cation concentration (0.1 M) were measured. The complex formation constants of the ligand could be calculated from the calibration plots of the relative absorbance vs. the activity ratios of cation and proton ($a_{M^+}/a_{H^+}$) and of the emf vs. pH. It was confirmed that the ratio values of the complex formation constants for the primary and interfering ions are closely related to the experimental selectivity coefficients of ISEs.

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HIGH RESOLUTION OBSERVATIONS OF MOLECULAR GAS DISTRIBUTION IN GALAXIES

  • YUN MIN S.
    • Journal of The Korean Astronomical Society
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    • 제29권spc1호
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    • pp.159-160
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    • 1996
  • Recent high resolution CO observations of normal and starburst galaxies at Owens Valley Millimeter Array are summarized. While normal disk galaxies generally show exponential distribution which follows the optical blue light, starburst galaxies are often characterized by a compact ($\~$1 kpc) nuclear complex whose surface gas mass density is strongly correlated with the observed large infrared luminosity and thus the ongoing massive star formation.

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