Photophysics, Dynamics, and Energy Transfer in Rigid Mimics of GFP-based Systems

Engineering of novel systems capable of efficient energy capture and transfer in a predesigned pathway could potentially boost applications varying from organic photovoltaics to catalytic platforms and have implications for energy sustainability and green chemistry. While light-harvesting properties of different materials have been studied for decades, recently, there has been great progress in the understanding and modeling of short- and long-range energy transfer processes through utilization of metal-organic frameworks (MOFs). In this Forum Article, the recent advances in efficient multiple-chromophore coupling in well-defined metal-organic materials through mimicking a protein system possessing near 100% energy transfer are discussed. Utilization of a MOF as an efficient replica of a protein β-barrel to maintain chromophore emission was also demonstrated. Furthermore, we established a novel dependence of a photophysical response on an electronic configuration for chromophores with the benzylidene imidazolinone core. For that, we prepared 16 chromophores, in which the benzylidene imidazolinone core was modified with electron-donating and electron-withdrawing substituents. To establish the structure-dependent photophysical properties of the prepared chromophores, 11 novel molecular structures were determined by single-crystal X-ray diffraction. These findings allow one to predict the chromophore emission profile inside a rigid framework as a function of the substituent, a key parameter for achieving the spectral overlap necessary to study and increase resonance energy transfer efficiency in MOF-based materials.