SYNTHESIS, CRYSTAL-STRUCTURE AND PROPERTIES OF [SR2CU(C2O4)(3)(H2O)(7)] - PRECURSOR OF SR2CUO3 OXIDE

[Sr2Cu(C2O4)(3)(H2O)(7)] (C2O42- = oxalate ion) has been synthesized and characterized. The structure has been determined by X-ray diffraction methods. It crystallizes in the triclinic system, space group P ($) over bar 1 with a=6.349(2) Angstrom, b=10.258(2) Angstrom, c=15.737(2) Angstrom, alpha=73.21(1)degrees, beta=93.66(2)degrees, gamma=76.44(2)degrees, V=944.3(4)Angstrom(3), Z=2. The structure consists of an intricate network of Sr2+ and Cu2+ ions linked by oxalate and H2O groups. A nonacoordinated arrangement around the two strontium ions and a distorted octahedral geometry for the copper(ll) ions are observed. The thermal decomposition of this complex yields a unique and homogeneous phase at comparatively short reaction times and tower temperatures than the ceramic method. Conductivity measurements of the oxide obtained show semiconductor behaviour.