Reversibility in the formation reaction of a series of the oxo (peroxo) porphyrinatomolybdenums,[Mo VI O (tmp)(O 2)] 1,[Mo VI O (tdcpp)(O 2)] 2,[Mo VI O (ttp)(O 2)] 3,[Mo VI O (tdmpp)(O 2)] 4, and [Mo VI O (tpp)(O 2)] 5, was studied. In these dioxygen complexes with various porphyrin rings, two complexes, 2 and 4, were newly prepared by the solid-state reactions of corresponding Mo (IV) complexes with O 2. All the complexes ...