In a now-concluded project, Girolami studied the chemistry and photophysics of bis(porphyrinate) metal sandwich complexes in collaboration with Illinois Professor of Chemistry Kenneth S. Suslick. These complexes were proposed to mimic the conversion of light to chemical energy in photosynthesis. Girolami's group synthesized bis(porphyrin) complexes of thorium, uranium, zirconium, and hafnium, and showed that these complexes displayed photophysical properties similar to those of the “special pair”, a chlorophyll dimer present in the photosystem I reaction center.