Azidocuprate(II). Die Kristallstruktur von (PPh4)2[Cu2(N3)6]

Azidocuprates(II). Crystal Structure of (PPh₄)₂Cu₂(N₃)₆] (PPh₄)₂Cu(N₃)₄] and (PPh₄)₂Cu₂(N₃)₆], which is already known, are prepared from the corresponding chloro cuprates and excess silver azide in dichloro methane suspension. The azido cuprates form nonexplosive brown crystals of low sensitivity to moisture and are characterized by i.r. spectroscopy. (PPh₄)₂Cu₂(N₃)₆] was submitted to a X-ray crystallographic structural analysis (4284 observed, independent reflexions, R = 0.034). The compound crystallizes triclinic in the space group P1 with one formula unit per unit cell. The lattice parameters are a = 1047.4 pm; b = 1131.1 pm; c = 1179.4 pm; α = 101.26°; β = 109.31°; γ = 103.42°. The compound consists of PPh₄^⊕ cations and centrosymmetric anions Cu₂(N₃)₆]^2?, which meet D_2h-symmetry fairly well. In the anions the copper atoms are linked to a planar Cu₂N₂ four-membered ring by the N α atoms of two azide groups. The other azido ligands are bonded terminally and complete coordination number 4 at the Cu atoms which show planar geometry.