CRYSTAL AND MOLECULAR STRUCTURE OF RACEMIC BIS(PI-AZULENE)IRON

Bis(μ-azulene)iron, (C10H8)2Fe, crystallizes in the centrosymmetric monoclinic space group P21/c (C2h5 no. 14) with a = 7.523 (5) Å,b = 12.071 (4) Å, c = 15.419 (16) Å, β = 98.26 (4)°, Z = 4. Observed and calculated densities are 1.45 ± 0.03 and 1.496 g cm-3, respectively. A single-crystal X-ray diffraction study has been completed. Data to sin θ = 0.38 (Mo Kα radiation) were collected with a 0.01 °-incrementing Buerger automated diffractometer, and the structure was solved using conventional Patterson, Fourier, and least-squares refinement techniques. All atoms have been located, the final discrepancy index being RF = 7.95% for the 1162 independent nonzero reflections. The crystal consists of distinct molecular units of (C10H8)2Fe, separated by normal van der Waals distances. The molecule is found to be a highly substituted ferrocene in which two azulene systems have dimerized via ortho-para (i.e., 4-endo,6′-endo) coupling. © 1969, American Chemical Society. All rights reserved.