Synthesis, Crystal Structures, and Vibrational Spectra of Novel Azidopalladates of the Alkali Metals Cs 2 [Pd(N 3 ) 4 ] and Rb 2 [Pd(N 3 ) 4 ]· 2 / 3 H 2 O

The transparent dark orange compounds Cs 2 [Pd(N 3 ) 4 ] and Rb 2 [Pd(N 3 ) 4 ]· 2 / 3 H 2 O are synthesized by reaction of the respective binary alkali metal azides with K 2 PdCl 4 in aqueous solutions. According to single‐crystal X‐ray diffraction investigations, the novel ternary azidopalladates(II) crystallize in the monoclinic space group P 2 1 / c (no. 14) with a = 705.7(2) pm, b = 717.3(2) pm, c = 1125.2(5) pm, β = 104.58(2)°, mP 30 for Cs 2 [Pd(N 3 ) 4 ] and a = 1041.4(1) pm, b = 1292.9(2) pm, c = 1198.7(1) pm, β = 91.93(1)°, mP 102 for Rb 2 [Pd(N 3 ) 4 ]· 2 / 3 H 2 O, respectively. Predominant structural features of both compounds are discrete [Pd II (N 3 ) 4 ] 2– anions with palladium in a planar coordination by nitrogen, but differing in point group symmetries., The vibrational spectra of the compounds are analyzed based on the idealized point group C 4 h of the spectroscopically relevant unit, [Pd(N 3 ) 4 ] 2– taking into account the site symmetry splitting due to the symmetry reduction in the solid phase.