Watching energy transfer in metalloporphyrin heterodimers using stimulated X-ray Raman spectroscopy

Significance Energy transfer in multiporphyrin arrays is of fundamental interest and plays an important role in natural and artificial light harvesting. In this work, we show how ultrafast hard X-ray pulses may be used to create localized electronic wavepackets in a metalloporphyrin dimer. Energy migration between monomers is detected through a stimulated Raman process, resonant with the metal core. Combining the broad bandwidth of attosecond pulses with the localized nature of core orbitals results in a much higher degree of localization and temporal resolution than is possible with optical pulses.