Photocleavable Porphyrin Derivatives for Quantum Optics

Optical control of molecular beams is intriguing as it promises to become a new tool for mass spectrometry and quantum interferometry, where a single or two photons deterministically remove a tailored tag from a larger molecular structure, e. g., a polypeptide. This cleavage process can change the charge state of the macromolecule, provide reporting signals for both fragments by mass spectrometry and it can selectively remove the fragments from a molecular beam by the momentum recoil generated in the dissociation process. Here, we explore a series of porphyrin derivatives as candidates for photocleavage in the gas phase. They share a large, conjugated core which promises a high absorption cross section for visible light. We present the individualization and beam formation of candidate molecules and study their photo-dissociation under tunable, visible radiation. We observe a significant wavelength shift and broadening in the photocleavage cross section for molecules in the gas phase compared to those in solution and we find that a single photon can suffice to trigger the cleavage process.