The coordination polymer Pb(H2O)[Au(CN)(2)](2) (1) was synthesized by the reaction of KAu(CN)(2) and Pb(NO3)(2). The structure contains 1-D chains of lead(II)-OH2 linked via Au(CN)(2)(-) moieties, generating a 2-D slab; weak aurophilic interactions of 3.506(2) and 3.4885(5) angstrom occur within and between slabs. The geometry about each lead(II) is bicapped trigonal prismatic, having six N-bound cyanides at the prism vertices and waters at two of the faces. Dehydration at 175 degrees C yields microcrystalline Pb[Au(CN)(2)](2) (2). which, along with 1, was examined by C-13, N-15, H-1, and Pb-207 solid-state NMR methods. Two N-15 resonances are assigned to the mu(2)-bridging and hydrogen-bonding cyanides in 1. Upon dehydration, the Pb-207 NMR spectrum becomes axially symmetric and yields a reduced shielding span, indicating higher site symmetry, while the C-13 and N-15 spectra reveal a single cyanide. Although no single-crystal X-ray structure of 2 could be obtained, a structure is proposed on the basis of the NMR and X-ray powder data, consisting of a lead(II) center in a distorted square-prismatic environment, with cyanides present at each corner. The birefringence of single crystals of 1 is found to be 7.0 x 10(-2) at room temperature. This value is large compared to that of most optical materials and can be attributed to the anisotropy of the 2-D slabs of 1, with all C N bonds aligned in the same direction by the polarizable lead(II) center.