Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect
Air-Stable Gold Nanoparticles Ligated by Secondary Phosphine Oxides as Catalyst for the Chemoselective Hydrogenation of Substituted Aldehydes: a Remarkable Ligand Effect
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DOI：
10.1021/jacs.5b02802
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发表时间：
2015-06-24
影响因子：
15
通讯作者：
van Leeuwen, Piet W. N. M.
中科院分区：
文献类型：
--
作者：
Cano, Israel;Huertos, Miguel A.;van Leeuwen, Piet W. N. M.
空气稳定和均匀的金纳米颗粒（AuNPs，1a-5a）通过各种仲氧化膦（SPO）连接，[（RRP）-R-1-P-2（O）H] =（R-1 = Naph，R-2 = Bu-t，L1; R-1 = R-2 = Ph，L2; R-1 = Ph，R-2 = Naph，L3; R-1 = R-2 = Et，L4; R-1 = R-2 = Cy; L5; R-1 = R-2 = Bu-t，L6），其中：通过Nal 31 -4还原相应的Ann S-PO络合物，合成了电子和空间位阻性质的配合物。这些容易获得的配体允许形成分散良好的小纳米颗粒。(size 1.2-2.2 nm）），其通过使用广泛的各种技术来表征，例如透射电子显微镜、热重分析、U.Vvis、能量色散X射线、X射线光电子能谱（XPS）、衰减全反射傅里叶变换红外光谱。- （ATR FT-IR），和-交叉极化魔角旋转（CF MAS）NMR光谱。发现了显著的配体效应，并且CP IVIAS NMR实验使得我们能够探测与纳米颗粒表面配位的SPO的P-O键的极性的重要差异，这取决于含有芳基SPO的配体AuNP中的取代基的类型。仅携带SPO阴离子并且对醛氢化具有高度选择性。用烷基SPO制备的类似尺寸的AuN-P还含有SPOH，氢键键合到SPO阴离子。结果，它们含有较少的Au（I）'和较多的Au（O），这也由XPS证明。它们在醛氢化中的选择性和活性较低，并且现在在硝基氢化中显示出Ati（O）NPs的典型活性。
Air-stable and homogeneous gold nanoparticles (AuNPs, 1a-5a) ligated by Various secondary, phosphine oxides (SPOs), [(RRP)-R-1-P-2(O)H] = (R-1 = Naph, R-2 = Bu-t, L1; R-1 = R-2 = Ph, L2; R-1 = Ph, R-2 = Naph, L3; R-1 = R-2 = Et, L4; R-1 = R-2 = Cy; L5; R-1 = R-2 = Bu-t, L6), with different :electronic and steric properties were syrithesized via Nal31-4, reduction of the corresponding Ann S-PO complex, These reasily accessible ligands allow the -fon-nation, of well,dispersed an small nanopartides. (size 1.2-2.2 nm)) which were characterized by the use of a wide :variety of techniques, such as transmission electron microscopy, thermogravimettic analysis, U.Vvis, energy dispersive X-ray, X-ray photoelectron spectroscopy- (XPS); attenuated total reflectance Fourier transform infrared speCtroscopy. -(ATR FT-IR), and -cross polarization magic angle spinning (CF MAS) NMR spectroscopy. A pronounced, ligand -effect was found, and' CP IVIAS NMR experiments enabled 'us to probe important, differences in the polarity of the P-O 'bond of the SPOs coordinated to the nanoparticle surface depending on the type of Substituents in the ligand AuNPs containing aryl SPOs Carry - only SPO anions and are highly selective for aldehyde hydrogenation'. AuN-Ps of similar Size'made- with alkyl SPOs contain also SPOH, hydrogen bonded-to SPO anions. As a consequenee they corltain less Au(I) 'and more Au(O), as is also -evidenced by XPS. They are less selective arid active in aldehyde hydrogenation and' now show the typical activity of Ati(O)NPs in nitro group hydrogenation.