Crystal structure of 4-biphenylylferrocene

Abstract

Crystals of 4-biphenylylferrocene are monoclinic, a= 19·18, b= 7·79, c= 10·85 (all σ ca. 0·01)A, β= 91·8 (1)°, Z= 4, space group P21; there are two molecules of C22H18Fe per asymmetric unit. The structure was determined with Fe-Kα scintillation counter data (corrected for absorption) by Patterson and Fourier methods and was refined by least-squares calculations, the final R being 0·115 for 1579 observed reflexions. The mean bond distances are Fe–C = 2·02, C–C (five-membered rings)= 1·42, C–C (six-membered rings)= 1·40, C–C (between rings)= 1·50 A. The two independent molecules have slightly different conformations. In one the cyclopentadienyl rings are oriented about midway between the eclipsed and staggered conformations, and the first six-membered ring is rotated 10° out of the plane of the cyclopentadienyl ring to which it is bonded, with the second six-membered ring rotated a further 7°. In the second molecule the cyclopentadienyl rings are only ca. 5° from the fully eclipsed position, and the six-membered ring rotations are 2 and 12°. The intermolecular separations correspond to van der Waals interactions.