Center for Supramolecular Optoelectronic Materials and WCU Hybrid Materials Program, Department of Materials Science and Engineering, Seoul National University, ENG 445, Seoul 151-744, Korea.
J Am Chem Soc. 2010 Oct 6;132(39):13675-83. doi: 10.1021/ja1044665.
Color tuning and switching of the solid-state luminescence of organic materials are attractive subjects for both the fundamental research and practical applications such as optical recording. We report herein cyanostilbene-based highly luminescent molecular sheets which exhibit two-color fluorescence switching in response to pressure, temperature, and solvent vapor. The origin for the multistimuli luminescence switching is the two-directional shear-sliding capability of molecular sheets, which are formed via intermolecular multiple C-H···N and C-H···O hydrogen bonds. The resulting two distinctive crystal phases are promoted by different modes of local dipole coupling, which cause a substantial alternation of π-π overlap. These changes can be directly correlated with the subsequent intermolecular excitonic and excimeric coupling in both phases, as demonstrated by an in-depth theory-assisted spectroscopic and structural study. Finally, we have prepared a first device demonstrator for rewritable fluorescent optical recording media which showed multistimuli luminescence tuning with fast response. Our multistimuli responsive system is unique in terms of the slip-stacking of molecular sheets and thus provides a novel concept of rewritable fluorescent optical recording media.
有机材料的固态发光的颜色调谐和切换是基础研究和实际应用（如光学记录）都很吸引人的课题。我们在此报告了基于氰基二苯乙烯的高发光分子薄片，其在响应压力、温度和溶剂蒸气时表现出双色荧光切换。多刺激发光切换的起源是分子薄片的双向剪切滑动能力，分子薄片是通过分子间的多个 C-H···N 和 C-H···O 氢键形成的。不同的局部偶极耦合模式促进了两种独特的晶体相的形成，这导致了π-π 重叠的实质性改变。这些变化可以通过深入的理论辅助光谱和结构研究直接关联到两个相中的随后的分子间激子和激基复合物耦合。最后，我们制备了用于可重写荧光光学记录介质的第一个器件演示器，其显示了快速响应的多刺激发光调谐。我们的多刺激响应系统在分子薄片的滑动堆积方面是独特的，因此为可重写荧光光学记录介质提供了一个新的概念。
