Complete Experimental Structure Determination of the p(3 × 2) pg Phase of Glycine on Cu{110}
Complete Experimental Structure Determination of the p(3 × 2) pg Phase of Glycine on Cu{110}
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Cu{110} 上甘氨酸 p(3 × 2) pg 相的完整实验结构测定
DOI：
10.1021/jp2057282
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Zheleva Z
中科院分区：
文献类型：
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作者：
Zheleva Z
利用低能电子衍射（LEED）表面晶体学方法研究了甘氨酸在Cu{110}表面吸附的p（3 × 2）有序相的完整吸附几何结构.甘氨酸分子通过氨基的N原子和去质子化的羧酸酯基团的两个O原子与表面形成键，每个O原子具有单独的Cu原子，使得第一层中的每个Cu原子都参与键合。横向上，N原子最接近顶部位置（位移，0.41 π）。O原子从顶部位置不对称地位移了0.54和1.18 μ m，具有两个非常不同的O-Cu键长1.93和2.18 μ m。最上层的铜层的原子位置显示出小的弛豫在0.07 μ m的体积截断的表面几何形状。吸附物层的晶胞由两个甘氨酸分子组成，它们通过滑移线对称操作而相关。这项研究清楚地表明，一个显着的覆盖率的吸附质结构没有这种下滑线对称性必须被拒绝，在两个能量依赖的斑点强度（LEED-IV曲线）和系统的LEED图案缺席的理由。
We present a quantitative low-energy electron diffraction (LEED) surface-crystallographic study of the complete adsorption geometry of glycine adsorbed on Cu{110} in the ordered p(3 × 2) phase. The glycine molecules form bonds to the surface through the N atoms of the amino group and the two O atoms of the deprotonated carboxylate group, each with separate Cu atoms such that every Cu atom in the first layer is involved in a bond. Laterally, N atoms are nearest to the atop site (displacement, 0.41 Å). The O atoms are asymmetrically displaced from the atop site by 0.54 and 1.18 Å with two very different O–Cu bond lengths of 1.93 and 2.18 Å. The atom positions of the upper-most Cu layers show small relaxations within 0.07 Å of the bulk-truncated surface geometry. The unit cell of the adsorbate layer consists of two glycine molecules, which are related by a glide-line symmetry operation. This study clearly shows that a significant coverage of adsorbate structures without this glide-line symmetry must be rejected, on the grounds of both the energy dependence of the spot intensities (LEED-IV curves) and systematic absences in the LEED pattern.