ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of the cation on the anion structure in mixed bis(di-n-propylammonium) and bis(di-n-butylammonium) tetrahalocuprates(II)

J. Tomovič, Z. Biela, and J. Gažo

Department of Inorganic Chemistry, Slovak Technical University, CS-812 37Bratislava

Abstract: Mixed tetrahalocuprates(II) A₂CuCl_xBr_4-x (A=(n-C₃H₇)₂NH₂ , (n-C₄H₉)_2-NH₂; x = 0, 1, 2, 3, 4) were prepared and studied. According to the energies of the d—d transitions, ^-v = 8100—8800 cm^-1, the structure of the anion in [(n-C₄H₉)₂ NH₂]₂CuCl_xBr_4-x( appears to be a distorted tetrahedron. The structure of mixed tetrahalocuprates(II) having the (n-C₃H₇)₂NH²⁺ cation varies with x: the anion structure is tetrahedral for x = 0 and 1 and planar for x = 2, 3, and 4 (d—d transition energy; ^-v≈12 500 cm^-1). DTA curves of compounds with distorted tetrahedral anions show an endothermal change at a tempera­ ture lower than the melting point, suggesting a phase transition associated with a change in the molecular structure. On DTA curves of compounds having planar anions such a change was not observed.

Full paper in Portable Document Format: 381a75.pdf

Chemical Papers 38 (1) 75–83 (1984)