Die Synthese und Struktur von Clusteraziden: A4[Nb6Cl12(N3)6](H2O)2 mit A = Rb, Cs

Abstract

The new compounds A4[Nb6Cl12(N3)6](H2O)2 (A = Rb, Cs) were synthesized from In4[Nb6Cl12Cl6] by substituting six terminal Cl ligands and the In+ ions in methanolic solution. An X-ray structure refinement was performed on single-crystal data of Rb4[Nb6Cl12(N3)6](H2O)2 (1) (space group P1̄, Z = 1, a = 912.5(1) pm, b = 937.2(1) pm, c = 1062.0(1) pm, α = 96.88(2)°, β = 101.89(1)°, γ = 101.44(2)°) and Cs4[Nb6Cl12(N3)6](H2O)2 (2) (space group PI, Z = 1, a = 920.9(5) pm, b = 947.9(7) pm, c = 1091.8(7) pm, α = 96.89(6)°, β = 103.35(5)°, γ = 101.60(5)°. Each of the centrosymmetric [Nb6Cl12(N3)6]4- ions of the isotypic compounds contains six terminal azide groups at the corners of the octahedral niobium cluster (d̄Nb-N = 226(1) pm (1), 225(1) pm (2), bond angles Nb-N-N 120-127°). The [Nb6Cl12(N3)6]4- ions are linked via Rb-N and Rb-Cl interactions of the Rb+ ions to form a three-dimensional structure. Crystals of the compounds react explosively on heating or mechanical pressure.