New CuSO ₄ ‐related high‐temperature polymorph of Ag ^II SO ₄ **

Silver(II) compounds exhibit powerful oxidizing properties and strong magnetic superexchange, but most of them comprise fluoride ligands. AgSO4 is a rare fluorine-free salt Ag(II) which found some application in organic chemistry. Here, we report discovery new polymorph (β). The distinct nature the two polytypes established using powder X-ray diffraction, vibrational spectroscopy theoretical calculations. β crystallizes monoclinic system (P21/n) shows structural similarities with CuSO4. DFT calculations indicate very small differences energy polymorphs that relative stability should increase temperature. distortion orthorhombic CuSO4 prototype originates from an unprecedented antiferromagnetic interaction between Ag sites along unit cell diagonal.