Researchers from the Extreme Conditions Chemistry Laboratory (ECCL) at the Jožef Stefan Institute (Matic Belak Vivod, Matic Lozinšek, and Mirela Dragomir) along with their collaborators (Zvonko Jagličić, Graham King, Thomas C. Hansen), have introduced mechanochemistry as a novel method for synthesizing reactive silver(II) compounds. This innovative approach allowed them to prepare the first examples of binary mixed-valent silver(I,II) fluorides, Ag₃F₄ and Ag₂F₃. The crystal structures of these new compounds were determined using powder X-ray diffraction measurements at the Canadian Light Source (CLS) synchrotron. Magnetic measurements, along with neutron powder diffraction (NPD) data from the Institut Laue-Langevin (ILL), revealed that these binary silver(I,II) fluorides exhibit low dimensional (1D) antiferromagnetic behavior. These compelling results suggest that mechanochemical synthesis can expand the silver(II) chemistry, potentially enabling the preparation of other mixed-valent phases and compounds of transition metals in rare oxidation states. This study, published in the Journal of the American Chemical Society, is dedicated to the memory of Professor Dr. Boris Žemva.