Two new inorganic-organic polymeric hybrids [Sn(pcp)] and [Cu(pcp)], pcp = CH2(PhPO2)(2)(2-), have been synthesized and structurally chracterized. The tin derivative has been obtained by reaction of the p,p-diphenylmethylenediphosphinic acid (H(2)pcp) in water with SnCl(2)(.)2H(2)O, while the copper derivative has been synthesized through a hydrothermal reaction from the same H2pcp acid and Cu(O2CMe)(2)(H2O)-H-.. The structures of these compounds have been solved "ab initio" by X-ray powder diffraction (XRPD) data. [Sn(pcp)] has a ladder-like polymeric structure, with tin(II) centers bridged by diphenylmethylenediphosphinate ligands, and alternating six- and eight-membered rings. The hemilectic coordination around the metal shows the tin(II) lone pair to be operative, resulting in significant interaction mainly with a C-C bond of one phenyl ring. The [Cu(pcp)] complex displays a polymeric columnar structure formed by two intersecting sinusoidal ribbons of copper(II) ions bridged by the bifunctional phosphinate ligands. The intersections of the ribbons are made of dimeric units of pentacoordinated copper ions. Crystal data for [Sn(pcp)]: monoclinic, space group P2(1)/c, a = 11.2851 (1), b = 15.4495(6), c = 8.6830(1) angstrom, beta = 107.546(1)degrees, V = 1443.44(g) angstrom, Z = 4. Crystal data for [Cu(pcp)]: triclinic, space group P (1) over bar, a = 10.7126(4), b = 13.0719(4), c = 4.9272(3) angstrom, alpha = 92.067(5), beta = 95.902(7), gamma = 87.847(4)degrees, V = 685.47(7), Z = 2. The tin compound has been characterized by Sn-119 MAS NMR (magic-angle spinning NMR), revealing asymmetry in the valence electron cloud about tin. Low-temperature magnetic measurements of the copper compound have indicated the presence of weak antiferromagnetic interactions below 50 K.