In this work, we have isolated a pentadentate [P₂N₂S] phosphine-thiocarbohydrazone ligand, H₂L, with a bulky phosphine group in both linker domains that undergoes an oxidation process in solution. This ligand was synthesized by direct reaction between two equivalents of 2-diphenylphosphinebenzaldehyde and one equivalent of thiocarbohydrazide. Two types of crystals derived from this ligand were obtained and studied by X-ray diffraction spectroscopy. One structure corresponds to the monooxidized ligand H₂L(O) while the other indicates a dioxidation of the compound, H₂L(OO).