We have identified six new 4d(4) and 4d(5) compounds with isolated RuCl6 octahedra, with formulas (HMA)(4)RuCl6 center dot Cl (1; MA = methylamine), (HGly)(4)RuCl6 center dot Cl (2; gly = glycine), (HGly)(3)RuCl6 center dot 2H(2)O (3), (NH4)(2)RuCl6 (4), (HPy)(2)RuCl6 (5; py = pyridine), and H-2(4,4'-bpy)RuCl6 (6; 4,4'-bpy = 4,4'-bipyridine). We find that the temperature-dependent magnetization is well described by single-ion physics in the presence of spin-orbit coupling and negligible superexchange interactions. Further, we find that many compounds in the literature are also well described by single-ion physics, and our results demonstrate the importance of considering single-ion physics when evaluating candidate geometric frustrated magnets in the presence of spin orbit coupling.