Electron-Induced Reactions of Ru(CO) 4 I 2 : Gas Phase, Surface, and Electron Beam-Induced Deposition
Electron-Induced Reactions of Ru(CO) 4 I 2 : Gas Phase, Surface, and Electron Beam-Induced Deposition
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Ru(CO) 4 I 2 的电子诱导反应：气相、表面和电子束诱导沉积
DOI：
10.1021/acs.jpcc.0c01801
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Fairbrother, D. Howard
中科院分区：
文献类型：
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作者：
Thorman, Rachel M.;Jensen, Pernille A.;Yu, Jo-Chi;Matsuda, Scott J.;McElwee-White, Lisa;Ingólfsson, Oddur;Fairbrother, D. Howard
低能电子（<100 eV）与有机金属前驱体的反应是利用聚焦电子束诱导沉积制备含金属纳米结构的基础。为了在分子水平上理解这些反应，我们研究了Ru(CO) 4i2在三种不同环境下的电子诱导反应：在气相中作为分离分子，在表面上作为薄膜吸附，以及在俄格光谱仪中用于电子束诱导沉积（EBID）。气相研究表明，Ru(CO) 4i2的解离电子附着（DEA）主要导致两个CO配体的损失，而Ru(CO) 4i2的解离电离（DI）导致更广泛的碎片化。对钌（CO） 4i2薄膜的表面科学研究表明，在- 100°C下，钌（CO） 4i2薄膜在500 eV电子照射下吸附在金上，分解过程分为两个不同的步骤：(1)两个CO配体的初始损失，然后(2)一个较慢的步骤，剩余的两个CO配体解吸，在表面留下钌。EBID使用Ru(CO) 4i2及其溴化类似物Ru(CO)4Br2，生成钌卤化物比≈1:2且碳和氧污染最小的矿床。这些结果表明，在表面的初始沉积步骤中，DEA比DI占优势。这一步骤产生部分脱碳的Ru(CO) 2i2物质，然后在进一步的电子照射下进行CO解吸，这一发现可能推广到其他Ru(CO) 4x2物质（X =卤化物）。部分脱碳的中间体对CO的解吸与其他金属羰基（如W(CO)6）的解吸结果明显不同，这种差异初步归因于M-X键的存在。
The reactions of low energy (<100 eV) electrons with organometallic precursors underpin the fabrication of metal-containing nanostructures using focused electron beam-induced deposition. To understand these reactions at a molecular level, we have studied the electron-induced reactions of Ru(CO)4I2in three different environments: as isolated molecules in the gas phase, adsorbed as thin films on surfaces, and as used in electron beam-induced deposition (EBID) in an Auger spectrometer. Gas-phase studies show that dissociative electron attachment (DEA) to Ru(CO)4I2predominantly results in the loss of two CO ligands, while dissociative ionization (DI) of Ru(CO)4I2leads to significantly more extensive fragmentation. Surface science studies of thin films of Ru(CO)4I2adsorbed on gold at −100 °C and irradiated with 500 eV electrons show that decomposition proceeds in two distinct steps: (1) an initial loss of two CO ligands, followed by (2) a slower step, where the residual two CO ligands desorb, leaving RuI2on the surface. EBID using Ru(CO)4I2and its brominated analogue, Ru(CO)4Br2, produced deposits with a ruthenium-to-halide ratio of ≈1:2 and minimal carbon and oxygen contamination. These results suggest that DEA is dominant over DI in the initial deposition step on the surface. This step produces a partially decarbonylated Ru(CO)2I2species, which is then subject to CO desorption under further electron irradiation, findings likely generalizable to other Ru(CO)4X2species (X = halide). The desorption of CO from the partially decarbonylated intermediate differs markedly from the results obtained for other metal carbonyls (e.g., W(CO)6), a difference tentatively ascribed to the presence of M–X bonds.