Abstract
Tetraamminezinc(II) dipermanganate (Zn(NH~3~)~4~~2~; 1) was prepared, and its structure was elucidated with XRD‐Rietveld‐refinement and vibrational‐spectroscopy methods. Compound 1 has a cubic lattice consisting of a 3D H‐bound network built from blocks formed by four MnO$\rm{ {_{4}^{-}}}$ anions and four [Zn(NH~3~)~4~]^2+^ cations. The other four MnO$\rm{ {_{4}^{-}}}$ anions are located in a crystallographically different environment, namely in the cavities formed by the attachment of the building blocks. A low‐temperature quasi‐intramolecular redox reaction producing NH~4~NO~3~ and amorphous ZnMn~2~O~4~ could be established occurring even at 100°. Due to H‐bonds between the [Zn(NH~3~)~4~]^2+^ cation and the MnO$\rm{ {_{4}^{-}}}$ anion, a redox reaction took place between the NH~3~ and the anion; thus, thermal deammoniation of compound 1 cannot be used to prepare Zn(NH~3~)~2~~2~ (contrary to the behavior of the analogous perrhenate (ReO$\rm{ {_{4}^{-}}}$) complex). In solution‐phase deammoniation, a temperature‐dependent hydrolysis process leading to the formation of Zn(OH)~2~ and NH~4~MnO~4~ was observed. Refluxing 1 in toluene offering the heat convecting medium, followed by the removal of NH~4~NO~3~ by washing with H~2~O, proved to be an easy and convenient technique for the synthesis of the amorphous ZnMn~2~O~4~.