Polyhapto-Aromatic Interactions in Lead(II) Coordination

In its crystalline form, the Pb(II) complex of 1,3-diphenylpropane-1,3-dionate (dibenzoylmethanide, DBM-) can be regarded as
containing polymeric chains of centrosymmetric, dimeric Pb2(DBM)4
units linked through hexahapto interactions of the Pb atoms with
phenyl groups from adjacent units. Each Pb atom also appears to
be involved in intraunit dihapto-aromatic interactions, thus attaining
a total hapticity of thirteen. Comparison with the analogous Sn(II)
compound indicates that the unusually high coordination number
may reflect the capacity of Pb(II) to act as both a Lewis acid and
a Lewis base.