New Face-To-Face Metallocene Triads

The ferrocene compound 1-cyclopentadienyl-8-ferrocenylnaphthalene (5) is readily available
from 1,8-diiodonaphthalene and is shown to serve as a useful precursor to stacked trinuclear
complexes of general structure 1. Two new complexes of this type, an Fe−Co+−Fe (1b) and
an Fe−Ti(Cl2)-Fe (1c) triad, in addition to the Fe−Fe−Fe triad (1a) previously prepared,
are reported. The crystal structure of 1c has been determined. Individual molecules are
shown to adopt chiral conformations in the racemic crystal. Molecular distortions (Cp ring
twisting and splaying), which are associated with electronic charge on the Cp rings, are
found to be considerably greater in 1c than in 1a.