• 제목/요약/키워드: Phosphine

검색결과 118건 처리시간 0.031초

Pd(CF3CO2)2 착화합물 촉매에 의한 방향족 탄소-수소 결합의 활성화 반응 (Activation of Aromatic Carbon-Hydrogen Bonds by Palladium Trifluoroacetate Complexes)

  • 황영애;김동환;백두종
    • 대한화학회지
    • /
    • 제50권5호
    • /
    • pp.369-373
    • /
    • 2006
  • Pd(CF3CO2)2-phosphine 및 Pd(CF3CO2)2-sulfide 계를 촉매로 사용하여 styrene의 아릴화반응을 연구하였다. 주 생성물인 trans-stilbene의 수율은 phosphine 치환체의 염기도가 증가할수록 높아졌고 입체장애가 클수록 낮아졌다. arylphosphine에서 styrene으로 aryl 기가 이동하는 현상은 동일한 arylphosphine에 대하여 Pd(CF3CO2)2의 경우가 더 높은 염기도를 가진 Pd(CH3CO2)2의 경우보다 더 많이 나타났으므로 이 반응은 Pd 이온이 먼저 aryl 기에 공격을 하는 친전자성 메커니즘에 의해 진행된다고 본다. 한편 Pd(CF3CO2)2-sulfide보다 Pd(CF3CO2)2-phosphine 계가 더 효과적인 촉매로 작용하였다.

감마선 조사된 백삼의 생물학적 품질 및 저장특성 (Biological Quality and Storage Characteristics of Gamma-Irradiated Whilte Ginseng)

  • 권중호;변명우;이수정;이수정;정형욱
    • 한국식품영양과학회지
    • /
    • 제28권1호
    • /
    • pp.40-46
    • /
    • 1999
  • Microbiological quality of commercial white ginseng was examined, together with investigation on its water absorption pattern and radiosensitivity of molds isolated from the samples. Comparative effects of phosphine fumigation and gamma irradiation on microbial control and disinfestation of the samples packed in a commercial laminated film and stored for six months at ambient(20oC, 70% RH) and accelerated(40oC, 90% RH) conditions were studied. Commercial white ginseng was contaminated with coliforms by 103~104CFU/g and molds by 102~104CFU/g and thus decontamination process was required for hygienic quality and storage stability. Phosphine fumigation showed no sterilizing effects on microbes contaminated, while gamma irradiation at around 5kGy was effective for decontaminating microorganisms, showing D10 values of 0.48~0.60kGy for isolated molds. Even though the storage insects, Plodia interpuctella Hubner and Lasioderma serricorne(cigarette beetle) were easily destroyed by phosphine fumigation, gamma irradiation less than 5kGy was found effective for both purposes to improve biological quality of stored white ginseng, thereby extending the storage life of packed samples resulting from increased critical moisture content by about 1%(Aw 0.76).

  • PDF

리튬이차전지 난연성 전해액 첨가제로서의 Tris(2,4,6-trimethoxyphenyl)Phosphine의 열적, 전기화학적 특성 (Thermal and Electrochemical Studies of Tris(2,4,6-trimethoxyphenyl)Phosphine as a Flame Retardant Additive for Li-ion Battery)

  • 안세영;김기택;김현수
    • 한국전기전자재료학회논문지
    • /
    • 제21권12호
    • /
    • pp.1130-1134
    • /
    • 2008
  • Thermal and electrochemical properties were discussed with tris(2,4,6-trimethoxyphenyl)Phosphine (TTMPP) as a flame retradant additive for Li-ion battery. TTMPP showed excellent thermal stability with charged cathodes. Addition of 1 wt.% of the additive to the electrolyte improved the thermal stability without damaging the performance of the battery. The oxygne evolution reaction delayed nearly by $60^{\circ}C$. The capacity retention ratio in cycle life tests of the battery with 1 wt.% TTMPP was slightly improved comparing to the no additive cells.

Iron Catalyzed Atom Transfer Radical Polymerization of Methyl Methacrylate Using Diphenyl-2-pyridylphosphine as a Ligand

  • Xue, Zhigang;Noh, Seok-Kyun;Lyoo, Won-Seok
    • Macromolecular Research
    • /
    • 제15권4호
    • /
    • pp.302-307
    • /
    • 2007
  • The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.

三價稀土類元素의 溶媒推出上의 相乘效果 (Synergistic Effect in the Solvent Extraction of Trivalent Lanthanides by Neutral Phosphine Oxides)

  • 이진택
    • 대한화학회지
    • /
    • 제7권4호
    • /
    • pp.245-250
    • /
    • 1963
  • TBPO와 TOPO와의 混合溶媒(稀釋制 : toluene)에 依한 三假狀態의 4f 稀土類元素의 抽出에 있어 相乘效果(synerigistic effect)가 나타남을 알았으며 이것은 各 單獨溶媒系에 있어서 生成抽出되는 $M(NO_3)_3\;(TBPO)_3$$M(NO_3)_3\;(TOPO)_3$型 外에 $M(NO_3)_3\;(TBPO)_2\;(TOPO)$型이 새로히 追加生成됨을 起因된 것으로 認定된다.

  • PDF

High efficiency deep blue phosphorescent organic light emitting diodes using a phenylcarbazole type phosphine oxide as a host material

  • Jeon, Soon-Ok;Yook, Kyoung-Soo;Lee, Jun-Yeob
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
    • /
    • pp.188-191
    • /
    • 2009
  • A high efficiency deep blue phosphorescent organic light-emitting diode (PHOLED) was developed using a new wide triplet bandgap host material (PPO1) with a phenylcarbazole and a phosphine oxide unit. The wide triplet bandgap host material was synthesized by a phosphornation reaction of 2-bromo-Nphenylcarbazole with chlorodiphenylphosphine. A deep blue emitting phosphorescent dopant, tris((3,5-difluoro-4-cyanophenyl)pyridine)iridium (FCNIr), was doped into the PPO1 host and a high quantum efficiency of 17.1 % and a current efficiency of 19.5 cd/A with a color coordinate of (0.14,0.15) were achieved in the blue PHOLED. The quantum efficiency of the deep blue PHOLED was better than any other quantum efficiency value reported up to now.

  • PDF

PHOSPHINE AND JUPITER'S GREAT RED SPOT

  • Kim, Sang-Joon
    • Journal of Astronomy and Space Sciences
    • /
    • 제13권1호
    • /
    • pp.32-39
    • /
    • 1996
  • Voyager IRIS (Infrared Interferometer Spectrometer) observations of Jupiter's Great Red Spot (GRS) have been examined in order to extract the vertical distribution of phosphine. To the accuracy than can be achieved from this approach, there appears to be no difference between the PH3 distribution over the GRS compared with the distribution over the neighboring South Tropical Zone. This result is at variance with a pre-Voyager prediction of an enhancement of PH3 over the GRS resulting in the preferential production of red phosphorous in this location on the planet (Prinn & Lewis 1975). The composition of the red material remains an open question.

  • PDF