Structure of a new form of octaethylporphyrinato(methyl)rhodium(III)

C₃₇H₄₇N₄Rh, M_r = 650.72, triclinic, P1̄, a = 10.973(1), b = 11.875(1), c = 14.211 (1) Å, α = 108.03(1), β = 105.41(1), γ = 100.92(1)°, V = 1616.0 (7) ų, Z = 2, D_x = 1.337 g cm^-3, λ(Mo Kα₁) = 0.7093 Å, μ = 5.5 cm^-1, F(000) = 684, T = 295 K, final R = 0.044 for 4775 reflections [F₀ > 3σ(F_o)]. The present structure is different from the one reported earlier [Takenaka, Syal, Sasada, Omura, Ogoshi & Yoshida (1976). Acta Cryst. B32, 62-65]: the Rh-C distance is somewhat shorter [1.970 (4) Å]; all the ethyl groups, except for a disordered one, are oriented toward the methyl group attached to Rh; the two nearest neighbors form a 'dimer' in which the Rh-Rh distance is 4.67 Å and the mean plane separation is 3.35 Å.