Porous Honeycomb Self-Assembled Monolayers: Tripodal Adsorption and Hidden Chirality of Carboxylate Anchored Triptycenes on Ag.
Porous Honeycomb Self-Assembled Monolayers: Tripodal Adsorption and Hidden Chirality of Carboxylate Anchored Triptycenes on Ag.
复制标题
DOI：
10.1021/acsnano.1c03626
复制
发表时间：
2021-07-27
期刊：
影响因子：
17.1
通讯作者：
Zharnikov M
中科院分区：
文献类型：
--
作者：
Das S;Nascimbeni G;de la Morena RO;Ishiwari F;Shoji Y;Fukushima T;Buck M;Zojer E;Zharnikov M
具有三足锚定底物的分子代表了制造坚固的自组装单层（sam）的通用平台，补充了传统的单足方法。在这种情况下，我们研究了1,8,13-三羧基三tytycene （Trip-CA）在Ag（111）上的吸附，模拟了银原子在Au（111）上潜在沉积的双层吸附。虽然三脚架式SAM结构质量差且键构型不均匀，但具有三个羧酸锚定基团的三叶草支架可以产生高度结晶的SAM结构。观察到明显的多态性，并根据制备条件形成明显不同的结构。除了六角形分子排列外，蜂窝结构的出现特别有趣，因为这种开放结构对于由直立分子组成的sam来说是不寻常的。先进的光谱工具揭示了所有羧酸锚定基团的等效键合。值得注意的是，密度泛函理论计算预测了蜂窝网络中分子的手性排列，令人惊讶的是，这在实验扫描隧道显微镜（STM）图像中并不明显。理论和实验之间的这种表面上的差异可以通过考虑吸附层实际电子结构的细节来解决。所提出的结果代表了解释复杂分子膜的STM图像的复杂性的示范展示。它们也进一步证明了三甲烯作为生成具有不寻常结构基序的定义明确的层的基本构建块的潜力。
Molecules with tripodal anchoring to substrates represent a versatile platform for the fabrication of robust self-assembled monolayers (SAMs), complementing the conventional monopodal approach. In this context, we studied the adsorption of 1,8,13-tricarboxytriptycene (Trip-CA) on Ag(111), mimicked by a bilayer of silver atoms underpotentially deposited on Au. While tripodal SAMs frequently suffer from poor structural quality and inhomogeneous bonding configurations, the triptycene scaffold featuring three carboxylic acid anchoring groups yields highly crystalline SAM structures. A pronounced polymorphism is observed, with the formation of distinctly different structures depending on preparation conditions. Besides hexagonal molecular arrangements, the occurrence of a honeycomb structure is particularly intriguing as such an open structure is unusual for SAMs consisting of upright-standing molecules. Advanced spectroscopic tools reveal an equivalent bonding of all carboxylic acid anchoring groups. Notably, density functional theory calculations predict a chiral arrangement of the molecules in the honeycomb network, which, surprisingly, is not apparent in experimental scanning tunneling microscopy (STM) images. This seeming discrepancy between theory and experiment can be resolved by considering the details of the actual electronic structure of the adsorbate layer. The presented results represent an exemplary showcase for the intricacy of interpreting STM images of complex molecular films. They are also further evidence for the potential of triptycenes as basic building blocks for generating well-defined layers with unusual structural motifs.
登录
查看更多内容
影响因子：
15
作者：
Chen, Kuang-Yen;Ivashenko, Oleksii;Feringa, Ben L.
通讯作者：
Feringa, Ben L.
影响因子：
3.7
作者：
BATSON, PE
通讯作者：
BATSON, PE
影响因子：
3.7
作者：
Aitchison, Hannah;Lu, Hao;Buck, Manfred
通讯作者：
Buck, Manfred
影响因子：
9.5
作者：
Benneckendorf, Frank S.;Rohnacher, Valentina;Muellen, Klaus
通讯作者：
Muellen, Klaus
影响因子：
4
作者：
An, Dong;Liu, Hongli;Li, Xianggao
通讯作者：
Li, Xianggao