TRIFERROCENYLBORANE - MOLECULAR-STRUCTURE IN SOLUTION AND IN THE SOLID-STATE

According to a single crystal X-ray structure determination all three ferrocenyl substituents of triferrocenylborane (1) adopt the same orientation with respect to the BC3-plane [P2(1)/c; monoclinic; Z = 4; a = 1353.5(3), b = 1695.6(3), c = 1056.4(2) pm, beta = 109.27(3)degrees]. The simulated X-ray powder pattern of the single crystal is identical with the powder diagram of a macroscopic sample, indicating the presence of a single diastereomer (la) in the solid state. However, at low temperature (< -95 degrees C) in solution, the C-13 NMR spectra suggest the presence of the second diastereomer (1b) in which one ferrocenyl group is oriented opposite to the other two with respect to the central BC3-plane.