The Molybdenum(V) and Tungsten(VI) Oxoazides [MoO(N 3 ) 3 ], [MoO(N 3 ) 3 ⋅2 CH 3 CN], [(bipy)MoO(N 3 ) 3 ], [MoO(N 3 ) 5 ] 2− , [WO(N 3 ) 4 ], and [WO(N 3 ) 4 ⋅CH 3 CN]

A series of novel molybdenum(V) and tungsten(VI) oxoazides was prepared starting from [MOF 4 ] (M=Mo, W) and Me 3 SiN 3 . While [WO(N 3 ) 4 ] was formed through fluoride–azide exchange in the reaction of Me 3 SiN 3 with WOF 4 in SO 2 solution, the reaction with MoOF 4 resulted in a reduction of Mo VI to Mo V and formation of [MoO(N 3 ) 3 ]. Carried out in acetonitrile solution, these reactions resulted in the isolation of the corresponding adducts [MoO(N 3 ) 3 ⋅2 CH 3 CN] and [WO(N 3 ) 4 ⋅CH 3 CN]. Subsequent reactions of [MoO(N 3 ) 3 ] with 2,2′‐bipyridine and [PPh 4 ][N 3 ] resulted in the formation and isolation of [(bipy)MoO(N 3 ) 3 ] and [PPh 4 ] 2 [MoO(N 3 ) 5 ], respectively. Most molybdenum(V) and tungsten(VI) oxoazides were fully characterized by their vibrational spectra, impact, friction and thermal sensitivity data and, in the case of [WO(N 3 ) 4 ⋅CH 3 CN], [(bipy)MoO(N 3 ) 3 ], and [PPh 4 ] 2 [MoO(N 3 ) 5 ], by their X‐ray crystal structures.