(Invited) Stimuli-Responsive Metal-Organic Frameworks

Development of stimuli-responsive materials is crucial for the next advancements in the technology and energy sectors. For instance, reversible tuning photophysical profiles of materials or modulation of energy transfer processes are key aspects for the development of next generation of logic gates, spatially- and temporally-resolved sensors, and on-demand drug delivery systems. Our recent efforts have focused on employment of metal-organic frameworks (MOFs) as a versatile platform for the material development, which contain photochromic moieties, allowing for tailoring MOF electronic and photophysical properties. In our work, confinement-imposed photophysics was probed for a variety of photoresponsive moieties including a not-well studied class of hydrazone-based photoswitches integrated into topologically distinct porous scaffolds. The performed studies involved a comprehensive analysis of photophysics-structure correlation performed for the first time in two-dimensional and three-dimensional porous frameworks using steady-state and time-resolved photoluminescence spectroscopy. This presentation will delineate our findings on a series of different frameworks with coordinatively immobilized photochromic molecules. Specifically, we will discuss static and dynamic tuning of photophysical and electronic properties through metal incorporation, guest encapsulation, and photoresponsive linker embedment. Our findings were employed to develop the first example of the field-effect transistor built upon photochromic MOFs foreshadowing framework implementation in the practical realm.