Synthesis and Characterization of <i>A</i>₃[ReO₄][ReO₃N] and <i>A</i>′₂[ReO₃N] (<i>A</i> = Rb, Cs; <i>A</i>′ = K, Cs)

Crystallographically phase‐pure samples of A 3 [ReO 4 ][ReO 3 N] with A = Rb, Cs are obtained from the reaction of NH 4 [ReO 4 ] in an alkali metal hydroxide flux. Both compounds are isotypic to the known compound K 3 [ReO 4 ][ReO 3 N] and crystallize in the space group R m . [1] A ′ 2 [ReO 3 N] with A ′ = K, Cs are also synthesized from the respective alkali metal hydroxides, but with an increased amount of the nitrogen source via adding ammonium chloride to the starting mixture. K 2 [ReO 3 N] crystallizes in the space group C 2/ m , whereas Cs 2 [ReO 3 N] crystallizes in the space group Pnma . Along with the characterization of the four novel crystal structures, the experimental results are further supported by Raman spectroscopy and quantum chemical calculations.