• Title/Summary/Keyword: Iodine chemistry

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A Study on the HI Decomposition by Carbon-Supported Platinum Catalyst (백금담지 활성탄소 촉매의 요오드화수소 분해 특성 연구)

  • Park, J.E.;Kim, J.M.;Kang, K.S.;Kim, C.H.;Kim, Y.H.;Park, C.S.;Bae, K.K.
    • Journal of Hydrogen and New Energy
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    • v.17 no.3
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    • pp.301-308
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    • 2006
  • The present work explores the effect of carbon-supported platinum catalyst on the HI decomposition using gas adsorption analyzer, thermogravimetry, X-ray diffractometry, scanning electron microscopy, and gas chromatography. For this purpose, three types of activated carbon (C), Pt/C-1 wt.%, and Pt/C-5 wt.% were prepared. The HI gas conversion is crucially influenced by the amount of Pt on the carbon support. The more the amount of Pt was, the higher results in the HI gas conversion. For three types of catalysts, HI conversion increased with increasing the decomposition temperature but with decreasing the space velocity. The increase of HI conversion with temperature was more pronounced in activated carbon than that in Pt/C. From EDX result, it was found that the activated carbon comprised higher amount of iodine than the Pt/C after the decomposition reaction. This implies that the HI conversion is closely related to the amount of Iodine.

The Complexes of Benzene with Halogens and Interhalogens in Carbon Tetrachloride (벤젠과 할로겐 또는 할로겐間化合物 사이의 錯物에 관한 연구)

  • Choi, Sang-Up;Chang, Suck-Joo;Kwon, Shoon-Ja
    • Journal of the Korean Chemical Society
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    • v.9 no.4
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    • pp.153-160
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    • 1965
  • Ultraviolet spectrophotometric investigations have been carried out on the systems of benzene with iodine, bromine, chlorine and iodine monobromide in carbon tetrachloride. The results reveal the formation of one to one molecular complexes of the type, $C_6H_6{\cdot}X_2\;or\;C_6H_6{\cdot}IX$ (X denotes halogen atoms). The equilibrium constants obtained at $25^{\circ}$for the complex formation are 0.173, 0.137, 0.0643 and 0.341 $lmole^{-1}$ for $C_6H_6{\cdot}I_2,\;C_6H_6{\cdot}Br_2,\;C_6H_6{\cdot}Cl_2\;and\;C_6H_6{\cdot}IBr$, respectively. These results combined with those obtained by other workers indicate that the relative stabilities of the benzene complexes decrease in the order, $ICl > IBr > I_2 > Br_2 > Cl_2.$ This order may be measure of their relative acidities toward benzene, which is explained in terms of the relative polarizabilities of halogen molecules and the relative electronegativities of halogen atoms.

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Crystal Structures of Vacuum Dehydrated Fully $Cd^{2+}$-Exchanged Zeolite A and of Its iodine Sorption Complex (카드뮴 이온으로 완전히 치환한 제올라이트 A를 진공 탈수한 구조와 이것에 요오드를 흡착한 결정구조)

  • Jang, Se-Bok;Han, Young-Wook;Kim, Yang
    • Korean Journal of Crystallography
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    • v.4 no.2
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    • pp.54-62
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    • 1993
  • The crystal shnture of dehydrated fully Cd2+-exchanged zeolite A evacuated at 2 × 10-6 Torr and 650℃ (a:12.189(2) A) and of its iodine sorption corrplex (a:12.168(2)A) have been netsmlmn by single uystal x-ray diffraction techliques in the cubic space group hkTn at 21(1)℃. The strutures were refined to final error indices, Ri:0.057 and R2 =0.063 with 186 reflections and Rl:0.082 and R2:0.085 with 181 reflections, respectively, for which 1>3σ(In both structure, six lie at two distinguished threefold axes of unit cell ten the crystal structure of an iodine sorption complex of Cd6-A four Cd2+ ions are recessed 0.69(1) A into the large cavity to complex each with from the (111) plane of 0(3), whereas two Cd2+ ions recessed 0.68(1) A into the sodalite unit Awximately 4.0 l3ions per nit cell are sorbed. Each bridge between a Cd2+ ion and 8-ring oxygens ((I-I-I)= 117(1) ˚ and 0(1)-I(1)-I(2)=172(1)). The near linear I-I-0 angle and its interatomic distance (I-0=3.57(3) A) are indicative of a weak charge transfer interacticn between the frarrework oxygen and iodine. The existence of In3 inside the large cavity indicates that the If ions and H ions may be produced by reaction of In vapor with water molecules which maybe associated with Cd2+ ions in partially dehydrated Cd6-A In3- ions may be produced by the combination of I- and I2.

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The Effects of Charge Transfer Complex on the Reaction of N,N-dimethylaniline and Iodine (N,N-Dimethylaniline과 Iodine간의 반응에 있어서 Charge Transfer Complex의 영향)

  • Oh-Yun Kwon;U-Hyon Paek;Eung-Ryul Kim
    • Journal of the Korean Chemical Society
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    • v.36 no.2
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    • pp.191-196
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    • 1992
  • Reaction of N,N-dimethylaniline(N,N-DMA) and iodine in $CHCl_3,\;CH_2Cl_2 : CHCl_3$(1:1), $CH_2Cl_2$(1:1), and CH2Cl2 has been studied kinetically by using conductivity method. Pseudo first-order rate constants ($k_{obs}$) and second-order rate constants ($k_{obs}$/[N,N-DMA]) are dependent on the N,N-DMA concentration. Second-order rate constants obtained were decreased with increasing N,N-DMA concentration. We analysed these results on the basis of formation of charge transfer complex as a reaction intermediate. From the construction of reaction scheme and activation parameters for the formation and transformation of charge transfer complex. The equilibrium constants decreased when the dielectric constant of solvent was increased, and the value is 1.9${\sim}$4.2$M^{-1}$. The rate of transformation are markedly affected by the solvent polarity.${\Delta}H^{\neq}$ is 6.3-12.6kJ/mol, and ${\Delta}S^{\neq}$ is large negative value of -234J/mol K.

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The Thermodynamics of the Formation of Polymethylbenzene-Halogens Charge Transfer Complexes (Ⅱ) (폴리메틸벤젠과 할로겐 사이의 전하이동착물 생성에 관한 열역학적 연구 (제2보))

  • Oh Cheun Kwun;Jeong Rim Kim
    • Journal of the Korean Chemical Society
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    • v.25 no.2
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    • pp.75-84
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    • 1981
  • Ultraviolet spectrophotometric investigations have been carried out on the systems of mesitylene with iodine, bromine, iodine monochloride and iodine monobromide in carbon tetrachloride. The results reveal the formation of the charge transfer complexes of the type, $C_6H_3(CH_3)_3{\cdot}X_2$ or $C_6H_3(CH_3)_3{\cdot}IX$ (X denotes halogen atoms). The equilibrium constants were obtained in consideration of that absorption maxima due to the formation of the charge transfer complexes shift to blue with the increasing temperatures. Thermodynamic parameters, ${\Delta}H$, ${\Delta}G$ and ${\Delta}S$ for the formation of the charge transfer complexes were calculated from these values. These results indicate that the relative stabilities of the mesitylene complexes at each temperature decrease in the order, ICl > IBr > $I_2$ > $Br_2$. This order may be a measure of their relative acidities toward mesitylene, which is explaned in terms of the relative polarizabilities of halogen molecules and the relative electronegativities of halogen atoms. These results combined with previous study of this series indicated that the relative stabilities of the polymethylbenzene complexes with iodine increase in the order Benzene < Toluene < Xylene < Mesitylene Thus, analysis of these findings is discussed.

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Comparative Study of Fatty Acid Composition and Characterization of Fixed Oil of Four Peanut Varieties Available in Pakistan

  • Akhtar, Hifza;Hamid, Shahnaz;Khan, Javed Iqbal
    • Natural Product Sciences
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    • v.11 no.4
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    • pp.225-228
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    • 2005
  • four varieties of ground nut (Arechis hypogea) were collected from different areas of Pakistan (Tillagang, Gujar khan, Hanoi and Pipplan) from Punjab province. The oils were extracted for the evaluation of lipid. Physico-chemical values of oils were determined like refractive index, peroxide value, unsaponifiable matter, acid value, iodine value, free fatty acid and ester value. The lipid profile as indicated by GLC showed that Palmitic acid ranged from 8.2-8.8%, proportions of oleic acid and linoleic acid varied from 57.8-59.87% and 22.5-24.1% respectively. Gujar khan variety of peanut has higher % age of oil (56.79). The higher yield of oil in this variety is not at the cost of any nutritional quality of peanut oil.

Preparation of Radiopharmaceutical (II) (방사성의약품(放射性醫藥品) 합성방식(合成方式)에 관(關)한 연구(硏究) -제 II 보-(第 II 報))

  • Kim, You-Sun;Kim, Tae-Young;Uhm, Kyung-Ja
    • The Korean Journal of Nuclear Medicine
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    • v.2 no.1
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    • pp.67-71
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    • 1968
  • Mercury bromo hydroxy propane-$Hg^{203},\;Tc-^{99m}$ colloidal, $Tc-^{99m}$ per technate (from $Tc-^{99m}$ Generator) were prepared and prepared products were tested their clinical usability to give agreeable results. Labelling of HSA by $Tc^{99m}$ and coagulation of HSA to MAA were conducted on a lab. scale. The iodine containning Radiopharmaceuticals; Hippuran, Sodiumiodide (inj), RISA, MAA, Rosebengal, Triolein, Phosphorus protein and $Mercury^{203}$ neohydrine were prepared by the conventional procedure. Total 206. 4 mC of Radiopharmaceuticals were prepared and 141.910 mC of them were distributed to the major users in this country.

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Synthesis and Electrical Conductivities of Poly(1,4-phenylenevinylene-co-2,3,5,6-tetramethyl-1,4-phenylenevinylene)s

  • Jin, Jung-Il;Kang, Heung-Joong;Shim, Hong-Ku
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.415-420
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    • 1990
  • A series of copolymers of poly(1,4-phenylenevinylene-co-2,3,5,6-tetramethyl- 1,4-phenylenevinylene), poly(PV-co-TMPV), were prepared in film forms from the precursor polymer films. The sulfonium salt precursor polymers were synthesized by copolymerization of the mixtures of the respective bis(sulfonium salt) monomers. All of the copolymer films could be doped with $FeCl_3$ to have high electrical conductivities and they showed good air stability. The maximum conductivity of the $FeCl_3$-doped films ranged $10^{-3}\;to\;10^2Scm^{-1}$ depending on the composition of the copolymer films. However, these copolymer films could not be doped with iodine. The coplanarity of PV and TMPV units in the main chain appears to be affected by steric effect of the methyl groups in the TMPV units.

Stereospecific C$_6$-Hydroxyethylation of the Penicillin Nucleus

  • Kim, Wan-Joo;Lee, Gwan-Sun;Shim, Sang-Chul
    • Bulletin of the Korean Chemical Society
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    • v.5 no.5
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    • pp.191-193
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    • 1984
  • 6, 6-Diiodopenicillanic acid was prepared from 6-aminopenicillanic acid using iodine-sodium iodide systems in good yield (60%). Enolates derived from 6-chloro-6-iodo-, 6,6-diiodo-penicillanate have been generated in situ by a metal-halogen exchange process at -$78^{\circ}C$ using methylmangnesium iodide and reacted with acetaldehyde to yield aldols. As the size of remaining halogen atom increases, the proportion of ${\beta}$-face attack was increased. In the case of 6,6-diiodopenicillanate, only ${\beta}$-face attack was observed yielding a single isomer (6S, 8R).

The Phase Separation Characteristics of Bunsen Reaction with HIx Solution in Sulfur-Iodine Hydrogen Production Process (황-요오드 수소 제조 공정에서 HIx 용액을 이용한 분젠 반응의 상 분리 특성)

  • Kim, Hyo-Sub;Hong, Dong-Woo;Han, Sang-Jin;Kim, Young-Ho;Park, Chu-Sik;Bae, Ki-Kwang
    • Journal of Hydrogen and New Energy
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    • v.21 no.6
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    • pp.479-486
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    • 2010
  • In order to confirm the effect of $HI_x$ solution on Bunsen reaction in Sulfur-Iodine thermochemical hydrogen production process, the reaction was investigated using $HI_x$ solution as a reactant. The phase separation characteristics of reaction with $HI_x$ solution were compared with the reaction using $I_2$ and $H_2O$ as reactants. Firstly, saturation points of $I_2$ in $HI_x$ solution at various temperatures were investigated to determine reaction conditions. With increasing temperature, the amounts of unreacted $I_2$ and $H_2O$ in $HI_x$ solution were increased, while impurities (HI in $H_2SO_4$ phase and $H_2SO_4$ in $HI_x$ phase) in each phase were decreased. The volumes of $H_2SO_4$ phase obtained from Bunsen reaction with $HI_x$ solution was relatively less than those obtained from the reaction with $I_2$ and $H_2O$. The difficulty of phase separation in Bunsen reaction using $HI_x$ solution may be due to the insufficient amount of $H_2O$ existed in $HI_x$ phase after reaction. Therefore, we concluded that the supplement amount of $H_2O$ should be calculated on the basis of the moles of HI and $H_2SO_4$ and added to the reaction system for good phase separation.