• 제목/요약/키워드: $CH_3I$

검색결과 520건 처리시간 0.023초

Thermal and Photochemistry of Methyl Iodide on Ice Film Grown on Cu(111)

  • Sohn, Young-Ku;White, John M.
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1470-1474
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    • 2009
  • Thermal and photochemistry of methyl iodide ($CH_3I)\;adsorbed\;on\;D_2O$ ice film on Cu(111) at 100 K were studied using temperature-programmed desorption (TPD) time-of-flight mass spectrometry (TOF-MS), X-ray and ultraviolet photoelectron spectroscopies. On the basis of TPD, multilayer and monolayer $CH_3I$ molecules desorb from $D_2O$ ice layer at 120 and 130 K, respectively. Photo-irradiation at 100 K exhibits dramatic changes in the TPD and I $3d_{5/2}\;XPS\;of\;CH_3I$ on ice film, due to a dramatic dissociation of $CH_3I$. The dissociation is likely activated by solvated electrons transferred from the metal substrate during photo-irradiation. No other photo-initiated reaction products were found within our instrumental detection limit. During photo-irradiation, the $CH_3I$, $CH_3$ and I could be trapped (or solvated) in ice film by rearrangement (and self-diffusion) of water molecules. A newly appeared parent molecular desorption peak at 145 K is attributed to trapped $CH_3I$. In addition, the $CH_3$ and I may diffuse through ice and chemisorb on Cu(111), indicated by TPD and I $d_{5/2}$ XPS taken with photo-irradiation time, respectively. No molecular ejection was found during photo-irradiation at 100 K. The work functions for $CH_3I/Cu(111),\;D_2O/Cu(111)\;and\;CH_3I/D_2$O/Cu(111) were all measured to be about 3.9 eV, 1.0 eV downward shift from that of clean Cu(111).

Control the crystal size by varying concentrations of precursors for the planar perovskite solar cells

  • Xie, Lin;Hwang, Heewon;Kim, Minjung;Kim, Kyungkon
    • Rapid Communication in Photoscience
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    • 제4권4호
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    • pp.79-81
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    • 2015
  • The influence of the grain size of the $CH_3NH_3PbI_3$ on the solar cell performance is investigated by controlling the ratio between $CH_3NH_3I$ and $PbI_2$ precursors. As the concentration of the precursors increased from 1.0M to 2.0M, the $CH_3NH_3PbI_3$ grain size increased from ~100nm to ~400nm. The solar cell utilizing the $CH_3NH_3PbI_3$ with large grain size shows improved photocurrent compared to the solar cell utilizing $CH_3NH_3PbI_3$ with small grain size, which is ascribed to the reduced recombination at the boundaries of grains.

trans-[FeH(NCS(Me)-S)(dppe)2]I 화합물의 trans-[FeNCS)2(Ph2P(O)CH2CH2P(O)Ph2)2][I3]로 산화 (Oxidation of trans-[FeH(NCS(Me)-S)(dppe)2]I to trans trans-[FeNCS)2(Ph2P(O)CH2CH2P(O)Ph2)2][I3](dppe=PPh2CH2CH2PPh2))

  • 이지화;이순원
    • 대한화학회지
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    • 제44권4호
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    • pp.311-315
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    • 2000
  • The Fe(II)-isothiocyanato complex $trans-[FeH(NCS)(dppe)_2]$ (1) eactedwith iodomethane(Mel) to give methyl isothiocyanide-Fe(n) complex, $trans-FeH(NCS(Me)-S)(dppe)_2]I(2)$. Compound 2 was oxidized to $trans-[Fe(NCS)_2(Ph_2P(O)CH_2CH_2P(O)Ph_2)_2][I_3]$ (3), which was structurally characterized by X-ray diffraction. The molecular structure of 3 showed a bent Fe-NCS group, Crystallographic data for 3: triclinic space group P1,a=11.071(2) A,b=12.054(2)A,c=12.121(1)A, $\alpha=101.02(1){\circ}C{\beta}=95.887(9){\circ}Cr=110.34(1){\circ}C$, $Z=1R(wR_2)=0.0567(0.1294)$.

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Cationic Iridium(I) Complex of Ethyl Cinnamate and Hydrogenation of Unsaturated Esters with Iridium(I)-Perchlorato Complex

  • Yang, Kyung-Joon;Chin, Chong-Shik
    • Bulletin of the Korean Chemical Society
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    • 제7권6호
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    • pp.466-468
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    • 1986
  • Reaction of $Ir(ClO_4)(CO)(PPh_3)_2$ with trans-$C_6H_5CH$ = $CHCO_2C_2H_5$ produces a new cationic iridium(I) complex, [Ir (trans-$C_6H_5CH$ = $CHCO_2C_2H_5)(CO)(PPh_3)_2]ClO_4$ where trans-$C_6H_5CH$ = $CHCO_2C_2H_5$ seems to be coordinated through the carbonyl oxygen rather than through the $\pi$-system of the olefinic group according to the spectral data. It has been found that Ir$(ClO_4)(CO)(PPh_3)_2$ catalyzes the hydrogenation of $CH_2$ = $CHCO_2C_2H_5$, trans-$CH_3CH$ = $CHCO_2C_2H_5$ and trans-$C_6H_5CH$ = $CHCO_2C_2H_5$ to $CH_3CH_2CO_2C_2H_5$, $CH_3CH_2CH_2CO_2C_2H_5$ and $C_6H_5CH_2CH_2CO_2C_2H_5$, respectively at room temperature under the atmospheric pressure of hydrogen. The relative rates of the hydrogenation of the unsaturated esters are mostly understood in terms of steric reasons.

Aminopropyl-Terminated Polydimethylsiloxane과 Trichlorogermyl 곁가지 그룹을 갖는 Polyamide 블록공중합체의 합성, 구조분석 및 열적거동 (Synthesis, Structural Characterization and Thermal Behaviour of Block Copolymers of Aminopropyl-Terminated Polydimethylsiloxane and Polyamide Having Trichlorogermyl Pendant Group)

  • Gill, Rohama;Mazhar, M.;Mahboob, Sumera;Siddiq, Muhammad
    • 폴리머
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    • 제32권3호
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    • pp.239-245
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    • 2008
  • Block copolymers of the general formula $[(-CO-R'-CO-HN-Ar-NH-CO-R'-CO)_xNH(CH_2)_3-(Me_2SiO)_y(CH_2)_3NH_2]_n$, [n=18.00 to 1175.0] where $R'=CH_2CH(CH_2GeCl_3)$;$CH_2CHGeCl_3CH_2$; and $Ar=-C_6H_4$;$-(o.CH_3C_6H_4)_2$;$-o.CH_3OC_6H_4)_2$;$-(o.CH_3C_6H_4)$ were prepared by a polycondensation reaction of polyamide containing a pendant trichlorogermyl group and terminal acid chloride $Cl(-CO-R'-CO-NH-Ar-NH-CO-R'-CO-)_xCl$ with aminopropyl-terminated polydimethylsiloxane $H_2N(CH_2)_3(Me_2SiO)_y-(CH_2)_3NH_2]$, (PDMS). These polymers were characterized by elemental analysis, $T_g$, FT-IR, $^1H$-NMR, solid state $^{13}C$-NMR, and molecular weight determination. The thermal stability of these copolymers was examined using thermal analysis techniques, such as TGA and DSC. Their molecular weights as determined by laser light scattering technique ranged $5.13{\times}10^5$ to $331{\times}10^5\;g/mol$. These polymers display their $T_g$ in the range of 337 to $393^{\circ}C$ with an average decomposition temperature at $582^{\circ}C$.

Mechanistic Aspects in the Grignard Coupling Reaction of Bis(chloromethyl)dimethylsilane with Trimethylchlorosilane

  • 조연석;유복렬;안삼영;정일남
    • Bulletin of the Korean Chemical Society
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    • 제20권4호
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    • pp.422-426
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    • 1999
  • The Grignard reactions of bis(chloromethyl)dimethylsilane (1) with trimethylchlorosilane (2) in THF give both the intermolecular C-Si coupling and intramolecular C-C coupling products. At beginning stage, 1 reacts with Mg to give the mono-Grignard reagent ClCH2Me2SiCH2MgCl (1) which undergoes the C-Si coupling reaction to give MC2Si(CH2SiMe3)2 3, or C-C coupling to a mixture of formula Me3SiCH2(SiMe2CH2CH2)nR1 (n = 1, 2, 3, ..; 4a, R1I = H: 4b, R1 = SiMe3). In the reaction, two reaction pathways are involved: a) Ⅰ reacts with 2 to give Me3SiCH2SiMe2CH2Cl 6 which further reacts with Mg to afford a Me2SiCH2Mel-SiCH2MgCl (Ⅱ) or b) I cyclizes intramolecularly to a silacyclopropane intermediate A, which undergoes a ring-opening polymerization by the nucleophilic attack of the intermediates I or Ⅱ, followed by the termination reaction with H2O and 2, to give 4a and 4b, respectively. As the mole ratio of 2/1 increased from 2 to 16 folds, the formation of product 3 increased from 16% to 47% while the formation of polymeric products 4 was reduced from 60% to 40%. The intermolecular C-Si coupling reaction of the pathway a becomes more favorable than the intramolecular C-C coupling reaction of the pathways b at the higher mole ratio of 2/1.

중국수의의 문헌적 고찰 (A Study on thed Literature of Chinese Shroud)

  • 유관순
    • 복식
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    • 제25권
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    • pp.117-118
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    • 1995
  • Chinese shroud through literatures are as follows. 1. Taetae, Sime i, P'oo, Hansam, Ko, Mal, Nukpaek, Kwatu, Cu'ungi, Pokk n, Myokmok, Ri, Aksu, Mo and m were used the most in China. 2. The cloths of Chinese shroud were p'o, Paek, Kyon and Kum. The colors of the Chinese shroud were Hyon, Hun and white. 3. The size of the Chinese shroud is as follows. The size of the Ch'ungi was similar to the size of jujube kernel, the length of Myokmok was one Ch' k two Ch'on or one Ch' k five Ch'on, the length of Aksu was one Ch' k two Ch'on and it's width was five Ch'on. The chil of Mo reached the hands and the length of Swae was three Ch' k and the length of m was five Ch'on. 4. In Chinese shroud, cotton was put in P'oo, Aksu was tide by the strings at two corners. Myokmok was tied by the strings of four corners. The tip of the m was divided and Mo wrapped the whole body. 5. The clothes of Soryom was nineteen Ch'ing. The clothes of Taeryom in Kun were one hundred Ch'ing in the Chinese. The impliment of Soryom were Kum, Kyo, Sange i, Sane i, Ch'im, Yok and Kyon in the Chinese shroud. In the case of the implement of Taeryom, the chinese shroud had Kum, Kyo, Sange i, Sane i, Ch'im and Yok.

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1,4-Dicyanobutene Bridged Binuclear Iridium (I, III) Complexes and Their Catalytic Activities

  • Park, Hwa-Kun;Chin, Chong-Shik
    • Bulletin of the Korean Chemical Society
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    • 제8권3호
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    • pp.185-189
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    • 1987
  • Reactions of $Ir(ClO)_4(CO)(PPh_3)_2$ with dicyano olefins, cis-NCCH = CH$CH_2$$CH_2$CN (cDC1B), trans-NCCH = CH$CH_2$$CH_2$CN (tDC1B), trans-NC$CH_2$CH = CH$CH_2$CN (tDC2B), and NC$CH_2$$CH_2$$CH_2$$CH_2$CN (DCB) produce binuclear dicationic iridium (I) complexes, $[(CO)(PPh_3)_2Ir-NC-A-CN-Ir(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (1a), tDC1B (1b), tDC2B (1c), DCB (1d)). Complexes 1a-1d react with hydrogen to give binuclear dicationic tetrahydrido iridium (Ⅲ ) complexes, $[(CO)(PPh_3)_2(H)_2Ir-NC-A-CN-Ir(H)_2(PPh_3)_2(CO)](ClO_4)_2$ (NC-A-CN = cDC1B (2a), tDC1B (2b), tDC2B (2c), DCB (2d)). Complexes 2a and 2b catalyze the hydrogenation of cDC1B and tDC1B, respectively to give DCB, while the complex 2c is catalytically active for the isomerization of tDC2B to give cDC1B and tDC1B and the hydrogenation of tDC2B to give DCB at $100^{\circ}C$.

핵이식을 위한 한우 난자 활성화 처리방법에 관한 연구 (Studies on Oocyte Activation Regimen for Nuclear Transfer in Hanwoo(Korean Cattle))

  • 임기순;양보석;박성재;양병철;장원경;박창식
    • 한국가축번식학회지
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    • 제24권3호
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    • pp.281-288
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    • 2000
  • 활성화처리를 위해 22시간 성숙된 난자를 5 $\mu$M ionomycin(I)에서 5분, 10 $\mu$M calcium ionophore(Ca)에서 5분, 2 mM 6-dimethylaminopurine(DMAP)에서 3시간 및 10 $\mu\textrm{g}$/$m\ell$ cycloheximide(CH)에서 6시간 동안 단용 또는 병용 처리하였다. 활성화 처리된 난자는 mCR$_1$aa 배양액 내에서 배양되었으며, 배양조건은 5% $CO_2$, 95% air 또는 5% $CO_2$, 5% $O_2$, 90% $N_2$ 이었다. 1 I, Ca DMAP 및 CH에 의해 처리된 난자의 48시간 난할율은 각각, 12.7%, 14.1%, 28.9% 및 22.9%였다. 그러나, 배반포는 형성되지 않았다. 2. I+DMAP, I+CH, Ca+DMAP및 Ca+CH에 의해 처리된 난자의 48시간 난할율은 각각, 96.9%, 82.1%, 93.1% 및 84.7%였고, 배반포 발생율은 각각, 10.4%, 5.3%, 17.6% 및 7.1%로, I 및 Ca를 이용하여 세포 내 칼슘수준을 증가시킨 후, DMAP로 3시간 동안 배양하였을 때, 배반포 발생율이 유의적으로 높았다(P<0.05). 3. I, Ca, DMAP 및 CH에 의해 단용 처리된 난자의 전핵 발생율은 각각, 5.4%, 3.6%, 28.3% 및 28.8%였다. 그러나, 병용 처리된 난자는 100%의 전핵 형성율을 나타냈다.

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Synthesis and Dissociation Constants of Cationic Rhodium (I)-Triphenylarsine Complexes of Unsaturated Nitriles and Aldehyde

  • Chin, Chong-Shik;Park, Jeong-Han;Shin, Sang-Young;Kim, Choong-Il
    • Bulletin of the Korean Chemical Society
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    • 제8권3호
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    • pp.179-183
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    • 1987
  • Reactions of $Rh(ClO_4)(CO)(AsPh_3)_2$ with unsaturated nitriles and aldehyde, L, produce a series of new cationic rhodium (I) complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ (L = $CH_2$ = CHCN, $CH_2$ = C($CH_3$)CN, trans-$CH_3CH$ = CHCN, $CH_2$ = CH$CH_2$CN, trans-$C_6H_5CH$ = CHCN, and trans-$C_6H_5CH$ = CHCHD) where L are coordinated through the nitrogen and oxygen, respectively but not through the ${\pi}$-system of the olefinic group. Dissociation constants for the reaction, $[RhL(CO)(AsPh_3)_2]ClO_4$ $\rightleftharpoons$ $Rh(ClO_4)(CO)(AsPh_3)_2$ + L, have been measured to be $1.20{\times}10^{-4}$ M (L = $CH_2$ = CHCN), $1.05{\times}10^{-4}$ M (L = $CH_2$ = C($CH_3$)CN, $3.26{\times}10^{-5}$ M (L = trans-$CH_3$CH = CHCN) and $6.45{\times}10^{-5}$ M (L = $CH_2$ = CH$CH_2$CN) in chlorobenzene at $25^{\circ}C, and higher than those of triphenylphosphine complexes, $[RhL(CO)(AsPh_3)_2]ClO_4$ where L are the corresponding nitriles that are coordinated through the nitrogen atom. The differences in dissociation constants seem to be predominantly due to the differences in ${\Delta}H$ (not due to the differences in ${\Delta}S$). The weaker Rh-N (unsaturated nitriles) bonding in $AsPh_3$ complexes than in $PPh_3$ complexes (based on ${\Delta}H$ values) suggests that the unsaturated nitriles in 2∼5 are good ${\sigma}$-donor and poor ${\pi}$-acceptor.