• Title/Summary/Keyword: PPh3

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Prevalence of Postprandial Hypotension in the Elderly People with Hypertension according to Mealtimes (고혈압노인의 식사시간 별 식후저혈압 발생실태)

  • Son, Jung Tae;Lee, Eunjoo;Kim, Hyeonmi
    • 한국노년학
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    • v.31 no.4
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    • pp.969-983
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    • 2011
  • The purposes of this study were to identify the degree of postprandial blood pressure reduction and the prevalence of postprandial hypotension by 3 different mealtimes of elderly people diagnosed with hypertension in nursing homes. After the informed and written consent, a total of 187 elderly people were recruited in the study. Systolic BP, diastolic BP were measured with ambulatory BP monitor every 15 minutes interval from 30 minutes before a meal until 120 minutes after each meal. The maximum SBP reduction was significantly bigger at breakfast than lunchtime or dinnertime. Among 187 elders, 137(73.4%) showed PPH at breakfast, 103(54.2%) at lunchtime, and 96(50.2%) at dinnertime. The most prevalent time point of PPH was 90 minutes after the initiation of a meal in all of 3 mealtimes. Among 8 measurement times, the prevalence of PPH was significantly higher in breakfast (3.0±2.7 times) than both lunchtime (2.1±2.5 times) and dinnertime (1.9±2.4 times). Although the occurrence of PPH by every mealtime should be taken into account in caring for the elderly, postprandial BP measurements need more attention after breakfast. Nurses should develop appropriate nursing interventions that can prevent postprandial blood pressure reduction in elderly people with hypertension.

N,N,N',N'-Tetrahalobenzene-1,3-disulfonamide/PPh3 as an Efficient System for the Preparation of Alkyl Halides

  • Ghorbani-Vaghei, Ramin;Shiri, Lotfi;Ghorbani-Choghamarani, Arash
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.820-822
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    • 2013
  • N,N,N',N'-Tetrabromobenzene-1,3-disulfonamide (TBBDA)/$PPh_3$ and N,N,N',N'-tetrachlorobenzene-1,3-disulfonamide (TCBDA)/$PPh_3$ are two highly reactive reagent systems for the conversion of alcohols corresponding into alkyl chlorides and bromides in moderate to excellent yields in dichloromethane at room temperature under mild and neutral conditions.

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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    • v.8 no.3
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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 $100^{\circ}C$.

Alkylhydridorhodium(Ⅲ) Route for Isomerization and Hydrogenation of Unsaturated Alcohols with Rh(ClO$_4)(CO)(PPh_3)_2$ and [Rh(CO)(PPh$_3)_3]ClO_4$ under Hydrogen

  • Chin, Chong-Shik;Park, Jeong-Han;Kim, Choon-Gil
    • Bulletin of the Korean Chemical Society
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    • v.10 no.4
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    • pp.360-362
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    • 1989
  • Catalytic isomerization of unsaturated alcohols to the corresponding carbonyl compounds with$Rh(ClO_4)(CO)(PPh_3)_2\;(1)\;and\;[Rh(CO)(PPh_3)_3]ClO_4$ (2) is faster under hydrogen (where hydrogenation also occurs to give saturated alcohols) than under nitrogen. The isomerization under hydrogen seems to occur through an alkylhydridorhodium(III) complex which also undergoes reductive elimination to give hydrogenation products, saturated alcohols. The isomerization under hydrogen is faster with 2 than with 1, which is understood by acceleration of the last step, enol formation by $PPh_3$ dissociated from 2 and present in the reaction mixture when 2 is used as catalyst. Relative rates of the isomerization observed for different unsaturated alcohols are interpreted by steric effects of substituted groups and numbers of hydrogens to be abstracted by the rhodium of the intermediate, alkylhydridorhodium(III) to undergo the reductive elimination to give enol which is then rapidly converted into a carbonyl compound. It has been observed that the hydrogenation is relatively significant when reactions occur slowly whereas the isomerization is predominant when reactions proceed rapidly.

PHOTOCHEMISTRY OF 1-PHENYL-4-(PENTAMETHYLDISILANYL)BUTA-1,2-DIYNE:$[PdCI_2(PPh_3)_2]$-CATALYZED REACTION

  • Lee, Seong-Taek;Baek, Eun-Kyung;Shim, Sang-Chul
    • Journal of Photoscience
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    • v.1 no.2
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    • pp.119-122
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    • 1994
  • $PdCI_2(PPh_3)_2$-catalyzed photolysis of 1-phenyl-4-(pentamethyldisilanyl)buta-1,3-diyne (1) in dry benzene gives 1,4-disilacyclohexa-2,5-diene type dimerization products(3-6) via silacyclopropene. The silacyclopropene is formed from the singlet excited state of 1 and this silacyclopropene reacts with $(PPh_3)_2Pd^0$to form palladasilacyclobutene. In this reaction, the silylene-palladium complex is generated and reacts with 1 to give another silacyclopropene. $PdCI_2(PPh_3)_2$catalyzed photolysis of 1 with other alkynes supports the involvement of this silylene complex.

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Catalytic Isomerization of Allyic Alcohols to Carbonyl Compounds with Rh(ClO$_4$)(CO)(PPh$_3)_2$ and [Rh(CO)(PPh$_3)_3$]ClO$_4$

  • Chin Chong Shik;Park Jeonghan;Kim Choongil
    • Bulletin of the Korean Chemical Society
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    • v.10 no.1
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    • pp.102-103
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    • 1989
  • Four coordinated rhodium(Ⅰ) complexes, Rh($ClO_4$)(CO)$(PPh_3)_2$ and [$Rh(CO)(PPh_3)_3$]$ClO_4$(2) catalyze the iosmerization of allylic alcohols to the corresponding carbonyl compounds at room temperature under nitrogen. The isomerization is faster with 2 than with 1, which is understood in terms of relative ease of the last step of the catalytic cycle, the reductive elimination of enol. Relative rates of the isomerization with 1 and 2 for different allylic alcohols are also explained by the relative ease of the enol elimination step in part. The first step of the catalytic cycle, the complex formation of the allylic alcohol through the ${\pi}-system$ of the olefinic group of the allylic alcohol and the following step, formation of hydridoallyl complex also seem to affect the overall rate of the isomerization.

Iridium(Ⅲ) Insertion into an Aromatic C-H Bond and Si-H Bond

  • Yang Nam Keun;Chung Dae-Eun;Ko Jaejung;Kang Sang Ook
    • Bulletin of the Korean Chemical Society
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    • v.13 no.6
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    • pp.627-631
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    • 1992
  • The dihydrido iridium(Ⅲ) complex [$Ir(PPh_3)_2H_2(ac)_2$]$BF_4$ (ac=acetone) reacts with 2-phenylpyridine and 7,8-benzoquinoline to yield the C-H activated complexes [$Ir(PPh_3)_2$H(ac)(L)]$BF_4$ (L= phenylpyridine; 7,8-benzoquioline). The dihydrido iridium(Ⅲ) complex [$Ir(PPh_3)_2H_2(ac)_2$]$BF_4$ also reacts with triaklysilane via an oxidative addition reaction to yield the trihydrido iridium complexes [$Ir(PPh_3)_2H_3SiR_3$]$BF_4$ (R =Et and Ph). The structual configuration was studied by conventional spectroscopy.

Synthesis and Characterization of Dinuclear Mo(Ⅲ) and V(Ⅲ) Complexes (Ⅴ) (몰리브덴(Ⅲ)과 바나듐(Ⅲ) 이핵 착물의 합성과 특성 (제5보))

  • Oh, Sang-Oh;Lyou, Eun-Young
    • Journal of the Korean Chemical Society
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    • v.39 no.7
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    • pp.530-537
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    • 1995
  • The neutral complexes $MCl_3(phda)(MeCN)]$ and $[MCl_3(PPh_3)_2(MeCN)]$ (M=Mo, V) were prepared by the reaction of $MCl_z$, (M=Mo; z=5, M=V; z=3) with N, P-donating ligands in acetonitrile solution. Addition of AgClO_4$ to these neutral monomeric complexes in acetone solution afforded $MCl_{3-n}L_2(MeCN)(S)_n](ClO_4)_n$ (n=1, 2 : s=solvent). Two types of asymmetrical homo- and hetero-dinuclear complexes have been synthesized. The type of chloride bridged dinuclear complex is $[(MeCN)(phda)ClM({\mu}-Cl)_2M'Cl(PPh_3)_2(MeCN)](ClO_4)_2.$ And the type of pyrazine bridged complex is $[(MeCN)(phda)Cl_2M({\mu}-pyz)M'Cl_2(PPh_3)_2(MeCN)](ClO_4)_2.$ These complexes were characterized by elemental analysis, $^1H,\;^13C$ NMR, IR, Far-IR and UV-Vis spectroscopy.

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DFT 계산을 이용한 Buchwald-Hartwig amination 반응 메커니즘 연구

  • Gang, Seong-U
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.371-383
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    • 2014
  • 이 연구에서는 팔라듐 착물 $Pd(PPh_3)_2$을 사용한 bromotoluene과 morpholine간의 coupling reaction (Buchwald-Hartwig amination) 반응 메커니즘을 계산화학적 방법을 이용하여 연구하였다. 용매화 자유에너지를 고려한 중간체 에너지를 비교하였으며, 반응물질이 o-bromotoluene 일 때와 p-bromotoluene 일 때, 반응 중간체로 monophosphine 착물이 형성되는 경우와 bisphosphine 착물이 형성되는 경우를 비교하였으며, 반응 중간체로 bisphosphine 착물이 형성되는 경우 cis 이성질체가 중간체인 경우와 trans 이성질체가 중간체인 경우를 비교하였다. 그 결과, 반응물로 p-bromotoluene을 사용할 때 o-bromotoluene을 사용할 때보다 중간체가 상대적으로 더 안정하여 더 좋은 수득률을 얻을 수 있을 것으로 예상되었다. 또한 $Pd(PPh_3)_n(o-tolyl)(N(CH_2CH_2)_2O)$ (n=1 또는 2) 중간체를 제외하고는 모든 경우에서 bisphosphine 중간체가 형성되는 반응경로가 더 안정한 것으로 밝혀졌다. 그리고 $Pd(PPh_3)_2ArBr$의 경우 trans 이성질체가 cis 이성질체보다 안정하지만 $Pd(PPh_3)_2Ar(N(CH_2CH_2)_2O)$의 경우 반대로 cis 이성질체가 trans 이성질체보다 안정한 것으로 나타났다.

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Hard Coatings on Polycarbonate Plate Using Phenylene Copolymers (폴리카보네이트 판 위에 Phenylene의 공중합체들을 이용한 하드 코팅)

  • Shin, Min Jae;Yang, Do Hyeon;Oh, Mee Hye;Yoon, Yeo Seong;Shin, Jae Sup
    • Journal of Adhesion and Interface
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    • v.9 no.3
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    • pp.1-6
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    • 2008
  • Hard coatings were deposited on a polycarbonate plate as potential substitutes for glass in cars. In this research the copolymers of p-polyphenylene (PPH) and m-phenylene (MPH) were synthesized, and using these copolymers the coatings were conducted on a polycarbonate plate. The hardness of the coating surface was affected with the mole ratio of PPH and MPH in the copolymer. When the mole ratio of PPH : MPH in the copolymer was 20 : 80, the coating showed 2H class of pencil hardness and also showed the best abrasion resistance.

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