Cyclopropenylidenes as Strong Carbene Anchoring Groups on Au Surfaces
Cyclopropenylidenes as Strong Carbene Anchoring Groups on Au Surfaces
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DOI：
10.1021/jacs.0c10743
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发表时间：
2020-11-25
影响因子：
15
通讯作者：
Roy, Xavier
中科院分区：
文献类型：
--
作者：
Doud, Evan A.;Starr, Rachel L.;Roy, Xavier
在金属表面创造稳定的分子单层是表面化学的一个基本挑战。n -杂环碳烯（NHCs）最近被证明可以形成自组装的单层，比传统的Au体系上的硫醇稳定得多。在这里，我们从理论上和实验上证明了最小的环碳，环丙烯，在不改变表面结构的情况下，比NHCs与金表面的结合更强。我们使用分子加合物BAC- co2作为前驱体在Au（111）上沉积了二（二异丙胺）环丙烯（BAC），并通过高分辨率x射线光电子能谱、原子力显微镜和扫描隧道显微镜确定了表面结合分子的结构、几何形状和行为。我们的实验得到了密度泛函理论计算BAC在Au（111）上的分子结合能及其电子结构的支持。我们的工作首次证明了除NHC以外的稳定碳的表面改性；更广泛地说，它推动了对金属表面上各种碳烯的进一步探索。
The creation of stable molecular monolayers on metallic surfaces is a fundamental challenge of surface chemistry. N-Heterocyclic carbenes (NHCs) were recently shown to form self-assembled monolayers that are significantly more stable than the traditional thiols on Au system. Here we theoretically and experimentally demonstrate that the smallest cyclic carbene, cyclopropenylidene, binds even more strongly than NHCs to Au surfaces without altering the surface structure. We deposit bis(diisopropylamino)cyclopropenylidene (BAC) on Au(111) using the molecular adduct BAC-CO2 as a precursor and determine the structure, geometry, and behavior of the surface-bound molecules through high-resolution X-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Our experiments are supported by density functional theory calculations of the molecular binding energy of BAC on Au(111) and its electronic structure. Our work is the first demonstration of surface modification with a stable carbene other than NHC; more broadly, it drives further exploration of various carbenes on metal surfaces.