Department of Chemistry and ‡Department of Physics & Engineering Physics, Tulane University , New Orleans, Louisiana 70118, United States.
Langmuir. 2015 Jan 13;31(1):578-86. doi: 10.1021/la504297w. Epub 2014 Dec 24.
The development of methods to grow well-ordered chromophore thin films on solid substrates is of importance because such surface-associated arrays have potential applications in the generation of functional electronic and optical materials and devices. In this article, we demonstrate a straightforward layer-by-layer (LBL) supramolecular deposition strategy to prepare numerous layers (up to 19) of functionalized perylene diimide (PDI) chromophores built upon a covalent scaffolding multivalent porphyrin monolayer. Our thin film formation strategy employs water as the immersion solvent and exploits the β-cyclodextrin-adamantane host-guest couple in addition to PDI based aromatic stacking. Within the resultant film the porphyrin scaffold is oriented close to parallel to the glass substrate while the PDI chromophores are aligned closer to the surface normal. Together, the porphyrin monolayer and the multi-PDI layers exhibit a large absorption bandwidth in the visible spectrum. Importantly, because a self-assembly strategy was utilized, when a single monolayer of PDI is deposited on the porphyrin scaffolding layer, this PDI monolayer can be readily disassembled by washing with DMF leading to the regeneration of the porphyrin monolayer. The PDI thin film can subsequently be regrown from the regenerated porphyrin surface. The reported LBL strategy will be of broad interest for researchers developing well-organized chromophoric films and materials due to its simplicity as well as the added advantage of being performed in sustainable and cost-effective aqueous media.
开发在固体基底上生长有序生色体薄膜的方法具有重要意义，因为这种表面相关的阵列在功能性电子和光学材料和器件的产生方面具有潜在的应用。在本文中，我们展示了一种直接的层层（LBL）超分子沉积策略，用于制备功能化苝二酰亚胺（PDI）生色体的许多层（多达 19 层），这些生色体构建在共价支架多价卟啉单层上。我们的薄膜形成策略采用水作为浸渍溶剂，并利用β-环糊精-金刚烷主客体对以及基于 PDI 的芳香堆积。在所得薄膜中，卟啉支架接近平行于玻璃基底取向，而 PDI 生色体更接近表面法线取向。同时，卟啉单层和多 PDI 层在可见光谱中表现出大的吸收带宽。重要的是，由于采用了自组装策略，当将单层 PDI 沉积在卟啉支架层上时，该 PDI 单层可以通过用 DMF 洗涤轻易地解组装，从而再生卟啉支架层。PDI 薄膜可以随后从再生的卟啉表面重新生长。由于其简单性以及在可持续和具有成本效益的水介质中进行的附加优势，所报道的 LBL 策略将引起开发有序生色体薄膜和材料的研究人员的广泛关注。
