The electron transfer in the Phos→Fullerene direction for all the complexes is consistent with the chemical potential () of the fragments (Table ):  characterizes the response of the system energy with respect to changes in the electron number, thus related to the electronegativity  through =- . Hence, electrons move from the system with high chemical potential (phosphorene, =-4.4 eV) to the one with low chemical potential (fullerenes, =-4.7 to -5.3 eV)