The Molybdenum(V) and Tungsten(VI) Oxoazides [MoO(N3)3], [MoO(N3)3⋅2 CH3CN], [(bipy)MoO(N3)3], [MoO(N3)5]2−, [WO(N3)4], and [WO(N3)4⋅CH3CN]

A series of novel molybdenum(V) and tungsten(VI) oxoazides was prepared starting from [MOF4] (M=Mo, W) and Me3SiN3. While [WO(N3)4] was formed through fluoride–azide exchange in the reaction of Me3SiN3 with WOF4 in SO2 solution, the reaction with MoOF4 resulted in a reduction of MoVI to MoV and formation of [MoO(N3)3]. Carried out in acetonitrile solution, these reactions resulted in the isolation of the corresponding adducts [MoO(N3)3⋅2 CH3CN] and [WO(N3)4⋅CH3CN]. Subsequent reactions of [MoO(N3)3] with 2,2′‐bipyridine and [PPh4][N3] resulted in the formation and isolation of [(bipy)MoO(N3)3] and [PPh4]2[MoO(N3)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(N3)4⋅CH3CN], [(bipy)MoO(N3)3], and [PPh4]2[MoO(N3)5], by their X‐ray crystal structures. Mo and W make an impact: A series of novel molybdenum(V) and tungsten(VI) oxoazides were obtained and characterized. [MoO(N3)3] and [WO(N3)4] were obtained by fluoride–azide exchange from [MOF4] and Me3SiN3 as very friction‐ and impact‐sensitive solids. With CH3CN, [MoO(N3)3] and [WO(N3)4] form stable acetonitrile adducts. The reactions of [MoO(N3)3] with 2,2′‐bipyridine and N3− afforded [(bipy)MoO(N3)3] and [MoO(N3)5]2−, respectively.