光响应性金属有机框架薄膜的设计制备和智能器件应用研究

Molecular device is a very important and hot research field in chemistry and nano-science, numerous previous researches mainly focus on the molecular devices with microscale motion and the research on organization or assemble of hundreds or millions of the microscale motion to an innovative macroscopic effect is very rare. For the problems that the macroscopic molecular device can’t be assembled in a controllable way via a traditional method, a controlled liquid-phase epitaxial layer-by-layer self-assemble method will be used in this study to realize the controllable preparation of the metal-organic framework(MOF) thin film molecule device based on the organic linkers with photoswitching side groups or main backbones. Such MOF thin films include three different MOF layers, each containing a different photoswitchable linker controlled by illumination with light pulses of a different color. Two side layers control the open or close of film windows and the middle layer is responsible for loading or releasing of guest molecules via photoswitchable polar or pore size changes. In addition, the relationship between the films’ structural and compositional characteristics with their photoswitching properties will be exhibited and the application of such film in photon-driven molecular pump that could pump molecule specific will be explored. The results based on the studies will provide new ideas and theoretical basis for the development of intelligent materials.

分子机器一直是化学和纳米科学领域的研究热点，前人大量的研究主要集中在微观尺度运动分子机器的设计和合成，如何将几百个乃至几百万个微观层面的机械运动有效地组装起来，转化为宏观层面的做功运动鲜有报道。针对传统的制备方法难以对宏观层面分子机器的组装及其微观结构分布进行控制的问题，本项目拟以含有不同光响应元件的有机配体为微观结构单元，通过可控液相外延层层自组装技术实现金属有机框架（MOF）薄膜分子机器的可控制备。该MOF薄膜含有三层不同的微观结构，每层的响应行为分别受不同波长光照控制，两侧层的结构分别实现薄膜两边窗口的可控开关效应，中间层结构的可控极性或孔径变化能够有效控制其对特定客体分子的吸附或释放。本研究将构建该MOF薄膜的成分结构与光响应性能的构-效关系，并探索其在宏观尺度光驱动分子泵上的应用，为智能材料的开发提出新的思路和理论依据。

针对传统的制备方法难以实现光响应性分子薄膜的组装及其微观结构的精确调控问题，本项目分别以含有不同光响应元件的有机配体为微观结构单元，通过可控液相外延层层自组装技术实现光响应性金属有机框架（MOF）薄膜的可控制备。本项目已成功制备了一系列偶氮苯基、卟啉基、二氢芘基和二芳基乙烯基有机配体及其相应金属有机框架薄膜，系统表征了其光响应性能，研究了其在光响应性气体扩散分离、光催化、光电流、宏观尺度光驱动分子泵、非线性光学及光生激子传输机理等方面上的应用，取得了一批重要的研究成果。该项目在执行期间以主持人为第一作者、通讯作者或共同通讯作者发表14篇标注有国家自然基金（Grant No. 21802036）的高水平SCI研究论文；申请中国专利12项，授权专利6项；参加国际国内学术会议5次，做口头报告4次；培养博士研究生1人和硕士研究生5人。