Complexes of (arylimido)molybdenum(V)

Article abstract of DOI:10.1021/ic50207a002

The preparations of the paramagnetic Mo(V) complexes Mo(NR)(S₂P(OEt)₂)₃ and Mo(NR)Cl(S₂P(OEt)₂)₂ (R = Ph and tol) from Mo(CO)₄Cl₂, NH₄S₂P(OEt)₂, and the aryl azides are described. The stability of the imido ligand in each complex to protonation is demonstrated. The isotropic ESR spectra of these complexes are notable. Every ligand in these complexes contains a magnetic nucleus (¹⁴N, ³¹P, and ^35,37Cl), and coupling to each of these nuclei is manifested in the ESR spectra. Superhyperfine coupling constants are obtained unambiguously, however, only after ¹⁵N labeling. Stereochemistries cannot be deduced with certainty either from ESR or infrared spectra or from chemical evidence. The reaction of Mo(Ntol)(S₂P(OEt)₂)₃ with H₂S produces the unusual tetranuclear compound [Mo(Ntol)S(S₂P(OEt)₂)]₄. The equilibrium constant relating this complex to the dinuclear compound has been determined. A rationalization of the tetranuclear nature of the compound is discussed, and a structure is suggested.