• Title/Summary/Keyword: Palladium

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Palladium(II) Schiff Base Complexes Derived from Allylamine and Vinylaniline

  • Uh, Yoon-Seo;Zhang, Hai-Wen;Vogels, Christopher M.;Decken, Andreae;Westcott, Stephen A.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.7
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    • pp.986-990
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    • 2004
  • Condensation of salicylaldehyde $(2-HOC_6H_4C(O)H)$ with allylamine afforded the unsaturated salicylaldimine, $2-HOC_6H_4C(H)=NCH_2CH=CH_2$. Similar reactivity was observed with substituted salicylaldehydes. Further reaction of these Schiff bases with palladium acetate or $Na_2PdCl_4$ afforded complexes of the type $PdL_2$, where L = deprotonated Schiff base. The molecular structure of the parent salicylaldimine palladium complex $[trans-(2-OC_6H_4C(H)=NCH_2CH=CH_2)_2Pd]$ (1) was characterized by an X-ray diffraction study. Crystals of 1 were monoclinic, space group $P2_1/n,\;a\;=\;14.0005(9)\;{\AA},\;b\;=7.2964(5)\;{\AA},\;c\;=\;17.5103(12)\;{\AA},\;{\beta}\;=\;100.189(1)^{\circ}$, Z = 4. Analogous chemistry with 4-vinylaniline also gave novel palladium complexes containing a pendant styryl group. Crystals of $[trans-(2-HOC_6H_4C(H)=N-4-C_6H_4CH=CH_2)_2Pd]$ (4) were monoclinic, space group $P2_1/c$, a = 13.7710(14) ${\AA}$, b = 11.0348(11) ${\AA}$, c = 7.8192(8) ${\AA}$, ${\beta}\;=\;98.817(2)^{\circ}$, Z = 2.

Effect of Geometrical shape and Cold work on Deformation and Hydrogen absorption behaivor in Palladium (팔라듐에서의 변형 및 수소흡수거동에 미치는 형상 및 가공의 영향)

  • Jung, Y.G.;Kim, K.H.;Kim, S.W.
    • Transactions of the Korean hydrogen and new energy society
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    • v.12 no.4
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    • pp.247-255
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    • 2001
  • The relation between the deformation and the geometrical shape, and the effect of cold work on the hydrogen absorption behavior in palladium were investigated. The Pd specimens used were plates and wires as cold worked and annealed states. The palladium plates and wires were loaded with hydrogen by electrochemical method. Experimental analyses were carried out through X -ray diffraction, micrometer measurement and decimal balance measurement. As the results, it is found that the effect of cold work on hydrogen absorption capacity was relatively small. The deformation of the palladium plates in thickness direction is larger than in other lateral directions whereas the palladium wires showed the same deformation ratio in all radius directions because of the circular distribution of coexisting $\alpha$ and $\beta$ phases. The products of plastic deformation such as slip lines and voids etc. were observed abundantly in all specimens although the specimens had undergone only once of a hydrogen absorption and desorption.

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Synthesis and Application of Oligo(3-Methylthiothiophene) Using Palladium Catalyst (Palladium 촉매를 이용한 Oligo(3-methylthiothiophene)의 합성과 응용)

  • Park, Sang-Ho;Jung, Moon-Young;Bae, Jin-Young
    • Polymer(Korea)
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    • v.31 no.6
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    • pp.469-473
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    • 2007
  • In this study, oligo(3-methylthiothiophene) was synthesized from thiophene derivative according to the method of reductive coupling using palladium catalyst. For the preparation of monomer, 3-methylthiothiophene was first synthesized through the metal-halogen exchange reaction of 3-bromothiophene with n-butyllithiuim, and the corresponding 2,5-dibromo-3-methylthiothiophene was formed by bromination. Their synthesis and characterization were determined by $^1H-NMR$ and ATR analyses. Thermal stability of the oligothiophene was monitored by thermogravimetric analysis (TGA). Thermal evaporation of the oligo(3-methylthiothiophene) on the substrate was attempted for OTFT applications.

Heat-induced coarsening of layer-by-layer assembled mixed Au and Pd nanoparticles

  • Shon, Young-Seok;Shon, Dayeon Judy;Truong, Van;Gavia, Diego J.;Torrico, Raul;Abate, Yohannes
    • Advances in nano research
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    • v.2 no.1
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    • pp.57-67
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    • 2014
  • This article shows the coarsening behavior of nanoparticle multilayers during heat treatments which produce larger metallic nanostructures with varying shapes and sizes on glass slides. Nanoparticle multilayer films are initially constructed via the layer-by-layer self-assembly of small and monodispersed gold and/or palladium nanoparticles with different compositions (gold only, palladium only, or both gold and palladium) and assembly orders (compounding layers of gold layers over palladium layers or vice versa). Upon heating the slides at $600^{\circ}C$, the surface nanoparticles undergo coalescence becoming larger nanostructured metallic films. UV-Vis results show a clear reliance of the layering sequence on the optical properties of these metal films, which demonstrates an importance of the outmost (top) layers in each nanoparticle multilayer films. Topographic surface features show that the heat treatments of nanoparticle multilayer films result in the nucleation of nanoparticles and the formation of metallic cluster structures. The results confirm that different composition and layering sequence of nanoparticle multilayer films clearly affect the coalescence behavior of nanoparticles during heat treatments.

Numerical Study on Hydrogen Absorption and Expansion Behavior on Palladium (팔라듐에 관한 수소저장과 팽창거동에 관한 수치해석)

  • Kim, S.W.;Hwang, C.M.;Jang, T.I.;Jung, Y.G.
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.3
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    • pp.256-264
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    • 2007
  • In order to calculate the relation between the hydrogen and the hydrogen absorption metals in the atomic level, Embedded Atom Method(EAM) is recommended. In this study, we had constructed the EAM programs from constitutive formulas and parameters of the hydrogen and palladium for the purpose of predicting the expansion behavior on hydrogen absorbing in the geometric shape of hydrogen absorption metals, as palladium bars and plates. And the EAM analyses data were compared with the experiment data by using electrochemical method. As results, it is note that the expansion rate in thickness of the palladium plate model by EAM analyses is about 4 times larger than width and length, be similar to experiment results. Also, in the microscopic and macroscopic level the expansion behavior through EAM analyses show good agreement with experiment data.

Effect of the Cation Part of Imidazolium Ionic Liquids on Synthesis of Palladium Particle (팔라듐 입자 제조에 미치는 이미다졸계 이온성액체의 양이온 효과)

  • Kim, Chang Soo;Ahn, Byoung Sung;Tae, Hyunman;Jeon, Seung Hye;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.23 no.5
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    • pp.510-513
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    • 2012
  • Palladium particles were synthesized by conventional chemical reduction method with ionic liquids. The size and shape of palladium particles were significantly affected by the cation parts of ionic liquids. This is mainly attributed to the different stabilities of the ionic liquid structure formed by the physical bond between the cation parts. Among ionic liquids with [$BF_{4}$] as an anion part, the hexyl substituent in the cation parts was more effective to synthesize palladium particles with the smaller size and more uniform shape.

Submicrospheres as Both a Template and the Catalyst Source. Silica Submicro-reactor Dotted with Palladium Nanoparticles as Catalysts

  • Kim, Sung Min;Noh, Tae Hwan;Jung, Ok-Sang
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1127-1130
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    • 2013
  • Formation of the monodisperse submicrospheres consisting of ionic palladium(II) complexes, $[(Me_4en)Pd(L)]_2(X)_4$($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; L = bis(4-(4-pyridylcarboxyl)phenyl)methane; $X^-=BF_4{^-}$ and $ClO_4{^-}$), has been carried out without any templates or additives. The submicrospheres were coated with silicates, and then calcined in air at $550^{\circ}C$ for 1 h, to efficiently form hollow-spherical $SiO_2$ submicro-reactors dotted with palladium(0) nanoparticles (PdNPs). That is, the submicrospheres act as both a template and a source of the palladium metal nanoparticles. The submicro-reactors containing nano-catalysts have been characterized by means of SEM, TEM, and XPS. Notably, the reactors were proved to be very effective for Suzuki-Miyaura cross-coupling and hydrogenation reactions.

Palladium(II) p-Tolylamide and Reaction with CO2 to Generate a Carbamato Derivative

  • Seul, Jung-Min;Park, Soon-Heum
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3745-3748
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    • 2010
  • Pd(II) p-tolylamide Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)(NH($C_6H_4Me$-p)) (1) was metathetically prepared by the reaction of Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)Cl with NaNH($C_6H_4Me$-p). Treatment of 1 with carbon dioxide affords the palladium(II) carbamate Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)(OC(O)NH($C_6H_4Me$-p)) (2), quantitatively. Complex 2 reacts with HX (X = Cl, OTf) to give Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)X, $NH_2$(p-Tol) and $CO_2$. Reaction of the palladium(II) carbamate with MeI produced Pd(2,6-$(Ph_2PCH_2)_2C_6H_3$)I along with generation of methyl N-tolylcarbamate MeOC(O)NH($C_6H_4Me$-p), exclusively.