期刊
CHEMICAL SCIENCE
卷 9, 期 6, 页码 1674-1685出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c7sc04752e
关键词
-
资金
- National Science Foundation [CHE-1610984, CHE-1310327]
- U.S. Department of Energy, Office of Basic Energy Sciences, Chemical Sciences program [DE-SC0016367]
- Siedle Foundation
- NSWC Crane Fellowship program
- Division Of Chemistry [1610984, 1310327] Funding Source: National Science Foundation
Metal-organic coordination networks at surfaces, formed by on-surface redox assembly, are of interest for designing specific and selective chemical function at surfaces for heterogeneous catalysts and other applications. The chemical reactivity of single-site transition metals in on-surface coordination networks, which is essential to these applications, has not previously been fully characterized. Here, we demonstrate with a surface-supported, single-site V system that not only are these sites active toward dioxygen activation, but the products of that reaction show much higher selectivity than traditional vanadium nanoparticles, leading to only one V-oxo product. We have studied the chemical reactivity of one-dimensional metal-organic vanadium - 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (DPTZ) chains with O-2. The electron-rich chains self-assemble through an on-surface redox process on the Au(100) surface and are characterized by X-ray photoelectron spectroscopy, scanning tunneling microscopy, high-resolution electron energy loss spectroscopy, and density functional theory. Reaction of V-DPTZ chains with O2 causes an increase in V oxidation state from V-II to V-IV, resulting in a single strongly bonded (DPTZ(2-)) (VO)-O-IV product and spillover of O to the Au surface. DFT calculations confirm these products and also suggest new candidate intermediate states, providing mechanistic insight into this on-surface reaction. In contrast, the oxidation of ligand-free V is less complete and results in multiple oxygen-bound products. This demonstrates the high chemical selectivity of single-site metal centers in metal-ligand complexes at surfaces compared to metal nanoislands.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据