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 Pb-2(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.