Molybdenum(V) on an oxide string. Formation and solution stability of the linear complex (mu-trans-dioxo(tetraphenylporphyrinato)molybdenato(V))-bis(oxo(tetraphenylporphyrinato)molybdenum(V) perchlorate

The unusual linear trinuclear complex [Mo3O4(TPP)(3)](+) is Formed in solut ion upon the reaction of [MoO(TPP)-(OClO3)] with {[MoO(TPP)](2)O}, and an e quilibrium between [Mo3O4(TPP)(3)](+) and its constituent species is rapidl y established. Spectrophotometric experiments suggest that [Mo3O4(TPP)(3)]( +) is the predominant species found in solutions resulting from the mixture of [MoO(TPP)(OClO3)] and {[MoO(TPP)](2)O}, and its formation is strongly f avored (log K = 5.5 +/- 0.5 M-1). No evidence of higher oligomers has been observed. A mechanism for the formation of [Mo3O4(TPP)(3)](+) by the contro lled hydrolysis of [MoO(TPP)(OClO3)] is proposed.