Structural and electrical characterization of polymeric haloplumbate(II) systems

The synthesis and the structural, thermal, and electrical characterization of haloplumbate(II) systems are described. The counterions are diprotonated Linear aliphatic amines, such as the 2-methylpentane-1,5-diamine (2meptH(2 )) and propane-1,3-diamine (pnH(2)) dications. The (2meptH(2))[PbCl4] and ( 2meptH(2))[PbBr4] are isostructural, space group Cc, with a = 24.140(4) Ang strom, b = 7.720(2) Angstrom, c = 7.795(2) Angstrom, beta = 98.1(1)degrees, Z = 4 for the chlorine compound and a = 24.539(4) Angstrom, b = 8.031(2) A ngstrom, c = 8.198(2) Angstrom, beta = 99.6(1)degrees, Z = 4 for the bromin e compound; the (2meptH(2))[Pb1.5I5] crystallizes in the triclinic P (1) ov er bar space group, with a = 11.803(3) Angstrom, b = 12.565(3) Angstrom, c = 8.494(8) Angstrom, alpha = 106.2(1)degrees, beta = 100.5(1)degrees, gamma = 117.4(1)degrees, Z = 2; the crystals of (pnH(2))[PbCl4] are orthorhombic , space group P2(1)2(1)2(1), a = 19.247(4) Angstrom, b = 7.862(2) Angstrom, c = 7.581(2) Angstrom, Z = 4; the (pnH(2))(2)[Pb1.5Br7]. H2O crystallizes in the triclinic P (1) over bar space group, with a = 11.517(3) Angstrom, b = 14.122(3) Angstrom, c = 8.149(2) Angstrom, alpha = 104.1(1)degrees, beta = 109.8(1)degrees, gamma = 77.5(1)degrees, Z = 2. Three different types of polymeric haloplumbate(II) systems were obtained: strictly monodimensional , (2meptH(2))[Pb1.5I5], ribbonlike, (pnH(2))(2)[Pb1.5Br7]. H2O, and perovsk ite-like structures, (pnH(2))[PbCl4] and (2meptH(2))[PbX4] (X = Cl, Br). Wo rthy of note is the presence of organic dications in their extended form, i ntercalated between the inorganic anions, which are at different distances, depending on the amine length. The nitrogen atoms of the ammonium cations interact with the inorganic anions forming a network of hydrogen bonds, whi ch contribute to the crystal packing.