Kinetically Trapped Two-Component Self-Assembled Adlayer
Kinetically Trapped Two-Component Self-Assembled Adlayer
复制标题
动力学捕获的两组分自组装吸附层
DOI：
10.1021/acs.jpcc.5b07120
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Hipps, K. W.
中科院分区：
文献类型：
--
作者：
Jahanbekam, Abdolreza;Chilukuri, Bhaskar;Mazur, Ursula;Hipps, K. W.
一个两个组件的自组装过程中，在三个不同的组成相的结果进行了观察和解释。使含有不同摩尔比的八乙基卟啉钴（CoOEP）和苯辛烷中的晕苯的溶液与清洁的Au（111）表面接触。在无相对浓度下，观察到CoOEP和晕苯相共存。相反，在中间浓度下，形成具有尖锐组成边界的新的1-1表面结构（1晕苯至1 CoOEP）。这种行为是不寻常的，因为只有弱的货车范德华力，表面电荷交换的轻微变化，和空间效应稳定的1-1结构，它发生在溶液浓度比是一个数量级不同于表面浓度。通过变温STM和密度泛函理论（DFT）研究了这种1-1结构的性质和三相（纯CoOEP，1-1和纯晕苯）之间的转变。CoOEP和coronene的吸附能，无论是在其单独的阶段，并在1-1结构的DFT确定。发现CoOEP的真空脱附能是晕苯的1.8倍，并且发现1-1组合物中的每个组分的脱附能大于相应的纯单层。通过每nm 2的能量测量，预测纯CoOEP是最强烈吸附的，预测晕苯是最不强烈吸附的，并且1-1结构保持中间位置。通过将样品加热至50 °C，可以观察到动力学稳定的1-1结构在与在22 °C下形成它的溶液相同的溶液下转化为纯CoOEP单层。这三种表面结构的存在被证明是一种动力学现象，而不是由于热力学。我们属性的存在下，在不同的生长浓度的三种结构的成核和生长速率的变化与每个组件的相对碰撞率。一个关键因素是一种组分（CoOEP）被不可逆地吸附的事实。新的1-1结构的晶格常数为A =（1.73 ± 0.04）nm，B =（1.56 ± 0.04）nm，α = 90° ± 2°，与Au（111）面相当。
A two-component self-assembly process that results in three different compositional phases is observed and explained. Solutions containing various molar ratios of cobalt octaethylporphyrin (CoOEP) and coronene in phenyloctane were brought into contact with a clean Au(111) surface. At no relative concentration was coexistence of the CoOEP and coronene phase observed. Rather, at intermediate concentrations a new 1–1 surface structure (1 coronene to 1 CoOEP) is formed with sharp compositional boundaries. This behavior is unusual in that only weak van der Waals forces, slight variations in surface charge exchange, and steric effects stabilize the 1–1 structure and that it occurs where the solution concentration ratio is an order of magnitude different than the surface concentration. The nature of this 1–1 structure and the transitions between the three phases (pure CoOEP, 1–1, and pure coronene) were studied by variable temperature STM and by density functional theory (DFT). Adsorption energies for CoOEP and coronene, both in their separate phases, and in the 1–1 structure were determined by DFT. The desorption energy into vacuum of CoOEP was found to be ∼1.8 times that of coronene, and the desorption energy of each component in the 1–1 composition was found to be greater than in the corresponding pure monolayer. Measured by energy per nm2, pure CoOEP is predicted to be the most strongly adsorbed, coronene is predicted to be the least strongly adsorbed, and the 1–1 structure holds an intermediate position. By heating the sample to 50 °C it is possible to observe the transformation of the kinetically stabilized 1–1 structure into the pure CoOEP monolayer under the same solution from which it is formed at 22 °C. The existence of these three surface structures is shown to be a kinetic phenomenon rather than due to thermodynamics. We attribute the existence of the three structures at various growth concentrations to changes in nucleation and growth rate with relative impingement rates of each component. A critical element is the fact that one component (CoOEP) is irreversibly adsorbed. The new 1–1 structure is found to have lattice constants of A = (1.73 ± 0.04) nm, B = (1.56 ± 0.04) nm, and α = 90° ± 2° and appears to be commensurate with the Au(111) surface.
登录
查看更多内容
影响因子：
1.5
作者：
Z. Zou;Lingyun Wei;F. Chen;Zhiming Liu;P. Thamyongkit;Robert S. Loewe;J. Lindsey;U. Mohideen;D. Bocian
通讯作者：
Z. Zou;Lingyun Wei;F. Chen;Zhiming Liu;P. Thamyongkit;Robert S. Loewe;J. Lindsey;U. Mohideen;D. Bocian
利用偶极相互作用控制自组装单层形态：1,5-（二取代）-蒽单层的制备、STM 图像分析和模拟
DOI：
--
发表时间：
2010
期刊：
影响因子：
--
作者：
Wenjun Tong
通讯作者：
Wenjun Tong
一种新型变温解决方案——固体界面扫描隧道显微镜
影响因子：
2.8
作者：
Abdolreza Jahanbekam;U. Mazur;K. W. Hipps
通讯作者：
K. W. Hipps
极性对取代酞菁和硫醇分子共吸附分子纳米结构的影响。
影响因子：
2.9
作者：
Zhi;S. Lei;Liangbing Gan;L. Wan;Chen Wang;C. Bai
通讯作者：
C. Bai
DOI：
10.1039/c3cp50808k
发表时间：
2013-07
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
Min Kyoung Kim;Yi Xue;Tereza Pašková;M. Zimmt
通讯作者：
Min Kyoung Kim;Yi Xue;Tereza Pašková;M. Zimmt