Molecular mechanism for the activation of Au-25(SCH2CH2Ph)(18) nanoclusters by imidazolium-based ionic liquids for catalysis

doi:10.1016/j.jcat.2016.01.011

	Molecular mechanism for the activation of Au-25(SCH2CH2Ph)(18) nanoclusters by imidazolium-based ionic liquids for catalysis
	Kim, Hyung J.1,3; Abroshan, Hadi 1; Li, Gao 1,2; Lin, Jizhi 2; Jin, Rongchao 1
刊名	JOURNAL OF CATALYSIS
	2016-05-01
卷号	337 页码:72-79
关键词	Gold Nanoclusters Au-25 Suzuki Cross Coupling Ionic Liquids Dft Calculation Md Simulation
ISSN号	0021-9517
DOI	10.1016/j.jcat.2016.01.011
文献子类	Article
英文摘要	Unavailable surface structures of nanocatalysts often pose a challenge to molecular-level understanding of catalytic mechanisms. Recent progress in the structural characterization of gold nanoclusters with atomic precision has enabled them to serve as excellent model systems to scrutinize structure-reactivity correlation. Here a case study is reported in which the full structure of the Au-25(SCH2CH2Ph)(18) nanocluster catalyst allows detailed mechanistic insight into the Suzuki cross coupling reaction pathways at the atomic/molecular level-in particular, the promotional effect of imidazolium-based ionic liquids (ILs) on the coupling reaction between phenylboronic acid and p-iodoanisole. The catalytic mechanisms are studied using UV-vis spectroscopy, MALDI mass spectrometry, density functional theory (DFT) calculations, and classical molecular dynamics (MD) simulations. Partial removal of thiolate ligands (-SR) and "Au-SR" units from the protected Au-25 cluster through interactions with imidazolium cations is deemed the promotion mechanism in the cross-coupling reaction. Both the experiment and DFT calculation indicate that the acidic proton at position 2 of the imidazolium ions plays an important role in the detachment of SR ligands and Au atoms from the nanocluster surface, which in turn allows the cross-coupling reaction to occur at a much milder temperature than in the absence of the IL promoter. Results suggest that oxidation of the active gold species not only prevents further fragmentation of the nanoparticles by the ILs but also increases the interaction of reactants with the catalysts, thereby improving the conversion rate. (C) 2016 Elsevier Inc. All rights reserved.
WOS关键词	AB-INITIO PSEUDOPOTENTIALS ; CROSS-COUPLING REACTIONS ; TRANSITION-ELEMENTS ; GOLD NANOCLUSTER ; CO2 CAPTURE ; OXIDATION ; NANOPARTICLES ; CLUSTERS ; EXCHANGE ; PERSPECTIVE
WOS研究方向	Chemistry ; Engineering
语种	英语
出版者	ACADEMIC PRESS INC ELSEVIER SCIENCE
WOS记录号	WOS:000374920400009
内容类型	期刊论文
源URL	[http://cas-ir.dicp.ac.cn/handle/321008/170816]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
通讯作者	Jin, Rongchao
作者单位	1.Carnegie Mellon Univ, Dept Chem, 4400 Fifth Ave, Pittsburgh, PA 15213 USA 2.Chinese Acad Sci, Dalian Inst Chem Phys, State Key Lab Catalysis, Gold Catalysis Res Ctr, Dalian 116023, Peoples R China 3.Korea Inst Adv Study, Sch Computat Sci, Seoul 130722, South Korea
推荐引用方式 GB/T 7714	Kim, Hyung J.,Abroshan, Hadi,Li, Gao,et al. Molecular mechanism for the activation of Au-25(SCH2CH2Ph)(18) nanoclusters by imidazolium-based ionic liquids for catalysis[J]. JOURNAL OF CATALYSIS,2016,337:72-79.
APA	Kim, Hyung J.,Abroshan, Hadi,Li, Gao,Lin, Jizhi,&Jin, Rongchao.(2016).Molecular mechanism for the activation of Au-25(SCH2CH2Ph)(18) nanoclusters by imidazolium-based ionic liquids for catalysis.JOURNAL OF CATALYSIS,337,72-79.
MLA	Kim, Hyung J.,et al."Molecular mechanism for the activation of Au-25(SCH2CH2Ph)(18) nanoclusters by imidazolium-based ionic liquids for catalysis".JOURNAL OF CATALYSIS 337(2016):72-79.