Synthese und Struktur von Mo2NCl7

Synthesis and Structure of Mo₂NCl₇ The reaction of VN with MoCl₅ at 175 °C in a sealed glass ampoule yields the molybdenum(V) nitride chloride Mo₂NCl₇ in form of air sensitive black crystals with the triclinic space group P1¯ and a = 905.7(8); b = 975.4((6); c = 1283.4(8) pm, α = 103.13(4)°; β = 109.83(5)° und γ = 98.58(5)°. The crystal structure is built up from dinuclear units [Mo₂N₂Cl₇]^3— and [Mo₂Cl₇]³⁺, which are connected by asymmetric nitrido bridges to form endless chains. Within both dinuclear units the Mo atoms are bridged by three Cl atoms resulting in a Mo‐Mo distance of 349.2(3) pm in the unit [Mo₂N₂Cl₇]^3—. In case of [Mo₂Cl₇]³⁺, however, a shorter Mo‐Mo distance of 289.4(3) pm is observed, which can be interpreted by a single bond. Correspondingly a reduced magnetic moment of 0.95 B.M. per Mo atom is observed.