硫醇分子在Au(111)表面吸附结构的DFT研究  

Study on Adsorption Structure of Thiol Molecules on Au(111) Surface by DFT Method

作　　者：贾近[1] 黄玉东[1] 龙军[1] 张红星[2] 

机构地区：[1]哈尔滨工业大学应用化学系,黑龙江哈尔滨150001 [2]吉林大学理论化学研究所理论化学计算国家重点实验室,吉林长春130023

出　　处：《化学与粘合》2006年第6期376-380,393,共6页Chemistry and Adhesion

基　　金：国家自然科学基金重点项目(编号:50333030);黑龙江省杰出青年科学基金(编号:JC04-12)

摘　　要：采用分子模拟方法对硫醇分子在Au（111）表面上的吸附行为进行了研究。对于化学吸附过程，采用了密度泛函理论（DFT）的算法对甲基硫醇和2-巯基乙醇的吸附结构和能量进行了分析。优化结果显示在头基硫原子的多种吸附位置中bridge—fcc位是最稳定的，S—C键相对于金表面法线形成53—54°的倾斜角。对于全覆盖率下的自组装有序结构，采用了分子动力学方法比较了3种不同排布形式的稳定性，结果证明含有5种链取向的C（4×2）结构最稳定。另外，采用DFT方法对电子结构的分析显示，在bridge—fcc吸附位上，硫原子的P电子和邻近的金原子的d电子通过杂化形成了新的成键轨道和反键轨道，这一过程通过对硫和金原子反应前后的局部态密度的分析，进行了详细的论证。The adsorption of thiol molecules on the Au （111 ） surface was investigated with computer simulation approach. The chemisorptions of methyhhiol and 2 - mercaptoethanol were examined on the basis of DFT calculations of the adsorption structures and energetic properties. The optimization results showed that the most stable ehemisorptions site was bridge - fee sites, and the S - C bond formed an angle of 50°- 54° with respect to the Au （ 111 ） surface normal. The stabilities of self - assembled ordered structures of thiol molecules at full coverage with three different arranged structures were investigated by molecular dynamics simulation, the results indicated that the C （ 4 × 2 ） structure with three chain orientations was most preferable. In addition, the DFT analysis of the electronic structure showed that the over hybridization of the p states of S atom with the d states of Au atom formed both bonding and antibonding orbital, and this process was well discussed by analyzing the partial electronic density of both before and after reaction of sulfide and gold atoms.

关 键 词：硫醇 DFT 自组装 吸附结构 电子结构 分子动力学 

分 类 号：TQ424.3[化学工程]