The crystal structure of 1,1′-dimethylferricenium tri-iodide

Abstract

The crystal structure of 1,1′-dimethylferricenium tri-iodide has been determined from three-dimensional X-ray data collected by counter methods, and refined by least-squares techniques to a final conventional R factor, based on F, of 3.5%, for 1278 independent reflections. The material crystallizes in a triclinic cell, space group P 1 , with dimensions a = 14.70(1), b = 7.440(6), c = 7.97(1) Å, α = 70.50(3)°, β = 81.49(3)° γ = 97.33 (4)°, Z = 2. Although the two independent tri-iodide anions in the structure lie at crystallographic centres, refinement of a structural model with a 50:50 disorder of asymmetric anions about the centres of symmetry gave a significantly better fit to the data than refinement of a model based on centrosymmetric anions. The II distances in the asymmetric anions are 2.85(2) 2.97(2) Å for one, and 2.86(3) and 3.00(3) Å for the other. The cyclopentadienyl rings in the cation are almost exactly eclipsed with the methyl groups adjacent. The rings are inclined at 6.6° to each other. Mean distances are Fe-ring (perpendicular) = 1.695(1), FeC(ring) = 2.073(5), CC(ring) = 1.401(5), CCH 3 = 1.49(1) Å.