Diaqua(nitrato-k(2)O,O ')bis(L-phenylalaninato-k(2)O,O ')lead(II) nitrate

Abstract

In the title complex, [Pb(C9H11NO2)(2)(NO3)(H2O)(2)] NO3, the cation is a monomeric species including zwitterionic aminoacids. In both zwitterions, rotation of the NH3+ groups about their C-N bonds is blocked by intermolecular N-H center dot center dot center dot O hydrogen bonds. Assuming a limit for Pb-O bond lengths of 3 angstrom, the Pb-II ion is coordinated by eight O atoms. Each phenylalaninate ligand coordinates asymmetrically, with one short and one long Pb-O bond. Coordinated water molecules are also found at significantly different distances, while the bidentate nitrate ion coordinates symmetrically. The resulting [(PbO8)-O-II] core is hemi-directed, with a void placed almost trans to a carboxylate group. However, the 6s(2) lone pair of the metal center can not be considered as stereochemically active, as a non-coordinating O atom of a nitrate belonging to a symmetry-related cation is placed in the empty hemisphere, with a short Pb center dot center dot center dot O separation of 3.035(10) angstrom.