ORGANIC INORGANIC COMPOSITE-MATERIALS - SYNTHESIS AND PROPERTIES OF ONE-DIMENSIONAL POLYMERIC HALOPLUMBATE(II) SYSTEMS/

In this paper we report the synthesis and the thermal, spectroscopic a nd electrical characterization of 1-D polymeric haloplumbates(II) of f ormula (A) [PbX(3)] (A=piperidinium (pdH), morpholinium (mpH) cation; X=Br, I for pdH and Cl, Br for mpH). For the morpholinium compounds we report also the structural analysis. The (mpH) [PbX(3)] (X=Cl, Br) co mplexes are isomorphous and crystallize in space group P2(1)2(1)2(1). The unit cell dimensions are a=15.249(3), b=8.001(2), c=7.625(2) Angst rom V=930.3(4) Angstrom(3), Z=4 for (mpH)[PbCl3] and a=15.760(3), b=8. 254(2), c=7.866(6) Angstrom, V=1023.2(4) Angstrom(3), Z=4 for (mpH) [P bBr3]. The final R value is 0.0428 (R(W)=0.0442) for (mpH) [PbCl3] and 0.0434 (R(W)=0.0453) for (mpH) [PbBr3]. The structure consists of mor pholinium cations and infinite polymeric anions [PbX(3)(-)](n); each l ead atom is surrounded by six halogen atoms forming a strongly distort ed octahedron; adjacent octahedra shate faces to form 1-D endless chai ns in which two consecutive lead atoms are bridged by three halogen at oms. The distortion in the (PbX(6)) octahedra of (mpH) [PbX(3)] enable s the metal ion to be involved in a semicoordinative bond with the oxy gen atom of the morpholinium cation, which makes the lead(II) coordina tion 6+1. All the structures are tridimensionally built up by a networ k of intermolecular N-H ... X bonds.