We choose low excitation energies for the synchrotron experiments to ensure that the measurements are as surface-sensitive as possible. For details on the calculation of the inelastic mean free paths for all experiments and photon energies we refer to the Supporting Information (Table ). Briefly, the experiments at the LowDosePES endstation probe mostly the first layer, considering an MoS2 monolayer thickness of about 0.7 nm. In contrast, the experiments at the lab spectrometer with an Al Kα source and an inelastic mean free path of the photoelectrons of ) ) and S2p3/2 (162.15 eV (Figure ) and 162.20 eV (Figure )) are typical for 2H-MoS2. Although we observe a slight difference of 50 meV between the fresh samples (e.g. due to different defect densities) , we do not expect a great influence from this difference on the interaction between the MoS2 and the phthalocyanines. The deposition of the first layer of CoPc and CoPcF16 causes a binding energy shift of the MoS2 core-level spectra.