The surface chemistry of octanoic acid was studied on a copper foil or a Cu(100) single crystal in ultrahigh vacuum using reflection-absorption infrared spectroscopy, temperature-programmed desorption, and supplemented by first-principles density functional theory (DFT) calculations. Octanoic acid adsorbs molecularly at 90 K, converting from a flat-lying species at low coverages to a more upright species at saturation. Adsorption at 300 K results in the formation of an η²-octanoate species, which binds with the alkyl group parallel to the surface with a tilted carboxylate group, as evidence by both infrared data and calculations. The flat-lying structure facilitates octanoate decomposition, which reacts by desorbing carbon dioxide at ~550 K. Increasing the octanoate coverage induces the alkyl chains to be more perpendicular to the surface to form a self-assembled monolayer with significant intermolecular van der Waals’ interactions. This stabilizes the adsorbate, which now decomposes by desorbing carbon dioxide at ~640 K, where infrared spectroscopy confirms that this also occurs by the carboxylate tilting towards the surface. The resulting heptyl species can either decompose by desorbing hydrogen or can also polymerize on the surface.

在超高真空下，使用反射吸收红外光谱法，程序升温脱附法对辛酸在铜箔或Cu（100）单晶上的表面化学进行了研究，并辅以第一原理密度泛函理论（DFT）计算。辛酸在90 K时会分子吸收，从低覆盖率的平坦物种转变为饱和时更直立的物种。吸附在在η的形成300K的结果²-辛酸酯类，其与具有倾斜羧酸酯基团的平行于表面的烷基结合，这是红外数据和计算的证据。平坦的结构有助于辛酸的分解，它通过在约550 K处解吸二氧化碳来进行反应。增加辛酸的覆盖率会导致烷基链更垂直于表面，从而形成具有明显的分子间范德华相互作用的自组装单层膜。这稳定了被吸附物，该被吸附物现在通过在〜640 K处解吸二氧化碳而分解，其中红外光谱确认这也是由于羧酸盐向表面倾斜而发生的。生成的庚基物质可以通过解吸氢而分解，也可以在表面聚合。