Synthesis, Structure, and Magnetic Properties of New Ru₂⁶⁺ Compounds

Three compounds containing the Ru26+ core have been prepared by clean and convenient synthetic routes: [Ru2(ap)4(OH2)][CF3SO3]2, [Ru2(ap)4F][PF6], and [Ru2(ap)4Cl][FeCl4] (ap = anilinopyridinate). The third one has been structurally characterized from a crystal of [Ru2(ap)4Cl][FeCl4]·2.5CH2Cl2 and contains the Ru26+ core in a coordination environment identical to that of an Ru25+ compound. The compound crystallizes in the triclinic space group P1̄, with a = 9.660(2) Å, b = 16.237(3) Å, c = 17.724(4) Å, α = 86.34(3)°, β = 77.19(3)°, γ = 78.34(3)°, and Z = 2. The Ru−Ru distance is 2.301(1) Å, and the magnetic moment indicates the presence of two unpaired electrons. A σ2π4δ2π*2 electron configuration is inferred.