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.