Mild hydrothermal synthesis of Cu(SeO(3)).2H(2)O: structural characterization, thermal, spectroscopic and magnetic studies.

Cu(SeO(3)).2H(2)O has been synthesized by hydrothermal technique under autogeneous pressure. The compound crystallizes in the P2(1)2(1)2(1) orthorhombic space group. The unit cell parameters are a=6.672(1), b=9.167(1) and c=7.372(1) A with Z=4. The crystal structure has been refined using the Rietveld method. The limit of thermal stability is 130 degrees C, temperature at which the water content is lost. Above 470 degrees C the compound decomposes in SeO(2)(g) and CuO(s). The IR spectrum shows the characteristic bands of the (SeO(3))(2-) oxoanion and water molecules. An intense absorption band characteristic of Cu(II) cations in five-coordination is observed in the diffuse reflectance spectrum. The ESR spectra are isotropic from room temperature to 4.2K, with g=2.13(1). Magnetic measurements confirm the existence of a global antiferromagnetic behavior with a spin canting phenomenon detected at, approximately, 30K.