Zhang L, Chatterjee A, Ebrahimi M, Leung K T
WATLab and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
J Chem Phys. 2009 Mar 28;130(12):121103. doi: 10.1063/1.3106762.
The growth of glycine film by thermal evaporation on Si(111)7 x 7 at room temperature has been studied by X-ray photoemission. In contrast to common carboxylic acids, glycine is found to adsorb on Si(111)7 x 7 dissociatively through cleavage of a N-H bond instead of O-H bond. The intricate evolution of the observed N 1s features at 399.1, 401.4, and 402.2 eV with increasing film thickness demonstrates the existence of a transitional adlayer between the first adlayer and the zwitterionic multilayer. This transitional adlayer is estimated to be 1-2 adlayer thick and is characterized by the presence of intermolecular N...HO hydrogen bond. An intramolecular proton transfer mechanism is proposed to account for the adsorption process through the amino group.
通过X射线光电子能谱研究了室温下甘氨酸薄膜在Si(111)7×7表面上的热蒸发生长过程。与常见的羧酸不同，发现甘氨酸通过N-H键的断裂而非O-H键的断裂以解离方式吸附在Si(111)7×7表面。随着薄膜厚度增加，在399.1、401.4和402.2 eV处观察到的N 1s特征的复杂演变表明，在第一层吸附层和两性离子多层之间存在一个过渡吸附层。该过渡吸附层估计为1-2个吸附层厚，其特征是存在分子间N...HO氢键。提出了一种分子内质子转移机制来解释通过氨基的吸附过程。
