Public Abstract

DE-FG02-87ER13808: Fundamental Studies of Light-induced Charge Transfer, Energy Transfer, and Energy Conversion with Supramolecular Systems

Award Status: Active

Institution: Northwestern University, Chicago, IL
UEI: KG76WYENL5K1
PM: Roizen, Jennifer

Most Recent Award Date: 06/09/2026
Number of Support Periods: 37
PI: Hupp, Joseph

Current Budget Period: 05/15/2026 - 05/14/2027
Current Project Period: 05/15/2026 - 05/14/2029

Public Abstract

Fundamental Studies of Light-induced Charge Transfer, Energy Transfer, and Energy Conversion with Supramolecular Systems Joseph T. Hupp, Dept. of Chemistry, Northwestern University, Evanston, IL 60208 Abtract: Natural photosynthetic systems collect and convert visible light into molecular excitons. They transport and then split excitons into energetic redox components capable of making and breaking chemical bonds – ultimately yielding desirable molecular and polymeric compounds. With photosynthesis as inspiration, this project explores and develops two ideas. The first is that artificial, molecular-scale light absorbers – when suitably organized as extended, nanoporous, crystalline arrays – can function as photon-harvesting antennas capable of directing and delivering excitonic energy to remotely sited, bond-building machinery. The second is that atomically well-defined clusters and related assemblies can be rendered reactant-accessible and controllably catalytic for proton-coupled, many-electron reactions capable of creating bonds and forming desirable chemical compounds. Integration of catalysts with antenna structures provides a basis for driving reactions photochemically. This project builds on recent proof-of-concept demonstrations in both the molecular light-harvesting and chemical catalysis realms. Via the project we seek to gain the fundamental science understanding needed answer the following sets of questions: · For crystalline, light-absorbing, metal-organic frameworks (MOFs) as antenna structures, what controls antenna size? For antenna-generated molecular excitons, how can transport directionality and efficacy be controlled? For selected MOFs, how important are unconventional transport mechanisms and how well do they work compared to conventional mechanisms? Can usefully predictive design rules be identified and rationalized? · For hydrogen-bonded organic frameworks (HOFs), can we understand light-harvesting antenna behavior via theory developed for crystalline organic molecular solids, i.e. contemporary extensions of Kasha’s model that consider wavefunction overlap for closely packed chromophores? Can we relate antenna size and exciton transport dynamics to detailed packing structure, e.g. degree of slip-stacking of molecular units? Can antenna size and transport dynamics be directly measured? · Can atomically well-defined, framework-supported, inorganic catalysts, initially developed in our laboratory for heterogeneous catalysis of gas-phase reactions (including C2- and C3-forming reactions) be adapted and exploited for photo-sensitized, condensed-phase, catalysis of proton-coupled, many-electron reactions relevant to Energy Science? In exploratory studies, can photo-sensitized upgrading of complex, petroleum-derived mixtures be demonstrated? · Can well-defined supramolecular assemblies be used as (photo)catalytic electron reservoirs for desirable, many-electron reactions? This project makes use of DOE-sponsored, high-intensity X-ray spectroscopy (APS) and ultrafast fluorescence microscopy (CNM) facilities at nearby Argonne National Laboratory.

Fundamental Studies of Light-induced Charge Transfer, Energy Transfer, and Energy

Conversion with Supramolecular Systems

Joseph T. Hupp, Dept. of Chemistry, Northwestern University, Evanston, IL 60208

Abtract: Natural photosynthetic systems collect and convert visible light into molecular excitons. They transport and then split excitons into energetic redox components capable of making and breaking chemical bonds – ultimately yielding desirable molecular and polymeric compounds. With photosynthesis as inspiration, this project explores and develops two ideas. The first is that artificial, molecular-scale light absorbers – when suitably organized as extended, nanoporous, crystalline arrays – can function as photon-harvesting antennas capable of directing and delivering excitonic energy to remotely sited, bond-building machinery. The second is that atomically well-defined clusters and related assemblies can be rendered reactant-accessible and controllably catalytic for proton-coupled, many-electron reactions capable of creating bonds and forming desirable chemical compounds. Integration of catalysts with antenna structures provides a basis for driving reactions photochemically. This project builds on recent proof-of-concept demonstrations in both the molecular light-harvesting and chemical catalysis realms. Via the project we seek to gain the fundamental science understanding needed answer the following sets of questions:

· For crystalline, light-absorbing, metal-organic frameworks (MOFs) as antenna structures, what controls antenna size? For antenna-generated molecular excitons, how can transport directionality and efficacy be controlled? For selected MOFs, how important are unconventional transport mechanisms and how well do they work compared to conventional mechanisms? Can usefully predictive design rules be identified and rationalized?

· For hydrogen-bonded organic frameworks (HOFs), can we understand light-harvesting antenna behavior via theory developed for crystalline organic molecular solids, i.e. contemporary extensions of Kasha’s model that consider wavefunction overlap for closely packed chromophores? Can we relate antenna size and exciton transport dynamics to detailed packing structure, e.g. degree of slip-stacking of molecular units? Can antenna size and transport dynamics be directly measured?

· Can atomically well-defined, framework-supported, inorganic catalysts, initially developed in our laboratory for heterogeneous catalysis of gas-phase reactions (including C2- and C3-forming reactions) be adapted and exploited for photo-sensitized, condensed-phase, catalysis of proton-coupled, many-electron reactions relevant to Energy Science? In exploratory studies, can photo-sensitized upgrading of complex, petroleum-derived mixtures be demonstrated?

· Can well-defined supramolecular assemblies be used as (photo)catalytic electron reservoirs for desirable, many-electron reactions?

This project makes use of DOE-sponsored, high-intensity X-ray spectroscopy (APS) and ultrafast fluorescence microscopy (CNM) facilities at nearby Argonne National Laboratory.