As part of a larger study into phase transitions, the structures of tetra-pyridine-silver(I) hexa-fluoro-phosphate, [Ag(C5H5N)4](PF6) or AgPy4PF6, and tetra-pyridine-silver(I) hexa-fluoro-anti-monate, [Ag(C5H5N)4](SbF6) or AgPy4SbF6, were determined at 300 and 100 K from single-crystal X-ray diffraction. The compounds are isostructural, crystallizing in the space group I with Z' = 1/4. Over the temperature range studied no evidence of a phase change was found. The dihedral angles between the pyridine rings are compared with similar cations from the literature and discussed.
