Crystal Structure and Electronic and Magnetic Properties of Hexacyanoosmate(III)

The [OsIII(CN)6]3- anion is prepared by chemical oxidation in
aqueous solution and isolated as yellow prisms of
[Ph4P]3[OsIII(CN)6]·6H2O (1). This species crystallizes in the triclinic
space group P1̄ with cell parameters a = 13.7609(11) Å, b =
16.2275(13) Å, c = 17.0895(14) Å, α = 91.4040(10)°, β =
109.3600(10)°, γ = 102.3970(10)°, V = 3497.4(5) Å3, and Z =
2. The slightly distorted octahedral moiety displays Os−C and C−N
bond lengths that average 2.058 and 1.146 Å, respectively. Spin−orbit-coupling splitting of the ground-state term dominates the NIR
region of the electronic spectrum and the magnetic behavior of 1.
The experimental information points to higher spin delocalization
over the coordinated cyanides than in [FeIII(CN)6]3-.