Stille cross‐coupling reaction using Pd/BaSO4 as catalyst reservoir

Stille cross‐coupling reactions between iodobenzene and tributylphenyltin were carried out in ethanol/water solution using different amounts of Pd/BaSO₄ as catalyst reservoir in a ligand‐free system and high yields were obtained. Other substituted biaryls were obtained with good yields. The catalyst can be reused up to three times with some loss in activity. Filtration of the catalyst and product extraction yielded a solution that kept its activity, showing the presence of Pd(0)/Pd(II) species that can be regarded as the true catalysts. Interestingly, both 2‐bromotiophene and chlorobenzene yielded the desired corresponding reaction products. Copyright © 2007 John Wiley & Sons, Ltd.     

Magnetostatic interaction studied by force microscopy in ultrahigh vacuum

3 (FeGe)₅ O₁₂ magnetic garnet, Co/Pt multilayer sample and the high coercivity BaFe₁₂O₁₉ single crystal. We have prepared in UHV by electron beam evaporation magnetic sensors/tips which allowed us to reach high sensitivity and high resolution of our microscope. Ideal UHV conditions (pressure 5×10^-11 \text{Torr}) helped us to observe domain wall contrast on all of studied samples by using a dynamic mode of operation of the force microscope. Received: 28 October 1996/Accepted: 5 November 1996     

Heterogeneous Pd/C-catalyzed ligand-free Suzuki-Miyaura coupling reaction using aryl boronic esters

Heterogeneous Pd/C-catalyzed Suzuki-Miyaura cross-coupling reaction of aryl boronic esters with aryl bromides was successfully carried out in aqueous media at room temperature without the use of a ligand such as phosphine derivatives.     

嵌入(或载在)Y型分子筛上Pd粒子的XPS研究

1前言早在70年代末80年代初，就有文献报道在载体上的金属Pd的某些性能，并注意到将其作为催化剂在甲醇合成上有很高的活性和选择性[1~3]，然而并没有继续进行系统研究．80年代末，Sachtler等人开始在这一领域进行更广泛、更细致、更深入的研究[4~8]．他们不仅研究了载在分子筛上的Pd，也研究了Pd与其他过渡金属所形成的合金的性能．它们的催化性质研究包括对CO加氢、新戊烷和氢解和异构化以及甲基环戊烷的开环和扩环反应[4~9]．对Pd的其他性质的研究，还包括采用TPR、TPD、TPO和TPMS等技术，分析了Pd或其合金等金属原子在NaY分子…     

Adsorption of methane and ethane, 2. Studies of metal blacks in a dynamic system

The irreversible adsorption of methane and ethane increases with increasing temperature on Pt, Pd and Rh blacks. Data indicate a one-carbon attachment of ethane on Pt and Pd. A two-carbon attachment of ethane is observed upon adsorption on Rh.     

Interaction of SO2 with O2 over mixed Pt, Pd, Pt?Pd and Pt?Ru oxidation catalysts and combined treatment of automobile exhaust gases

TPD, XPS IR methods were used to study how the composition of mixed Pt and Pd contacts over Al₂O₃ affects the nature of SO₂ complexes formed in the presence of O₂. Two types of sulfates of different structure and binding strength are formed in SO₂ oxidation by oxygen over Pt and Pd contacts. Introducing elements such as Co and Cr into the composition, one can significantly reduce the formation of weakly binding sulfate-1 as well as sulfate-2 too.     

Application of Pd-catalysed amines arylation for the synthesis of benzopolyazamacrocycles

Amination of 1,2- or 1,3-dihalobenzenes by linear polyamines in the presence of Pd(dba)₂/BINAP catalytic system can serve as a convenient one-pot procedure for the synthesis of benzopolyazamacrocycles.     

Synthesis and crystal structure of four Pd(II) complexes containing nido or closo carborane diphosphine ligands

Three Pd(II) complexes [Pd₂(μ-Cl)₂{7,8-(PPh₂)₂-7,8-C₂B₉H₁₀}₂] · 0.25CH₂Cl₂ (1), [Pd{7,8-(PPh₂)₂-7,8-C₂B₉H₁₀}₂] · 4CHCl₃ (2) and [PdCl₂(1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀)] (3) have been synthesized by the reactions of 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀ with PdCl₂ in acetonitrile, cyanophenyl and dichloromethane, respectively. A fourth complex, [PdI₂(1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀)] (4), was obtained by a ligand exchange reaction through the substitution of the Cl⁻ of complex 3 with I⁻. All four complexes have been characterized by elemental analysis, FT-IR, ¹H and ¹³C NMR spectroscopy and X-ray structure determination. Single crystal X-ray determination showed that the carborane cage, nido for 1, 2 and closo for 3, 4, was coordinated bidentately to the Pd atom through the two P atoms, and the geometry at the Pd atom was square-planar in all the complexes.