| Abstrakt: |
The crystal structure of a new natural compound NaCu2Cl3[N3C2H2]2[NH3]2·4H2O, (further denoted I in the text) from a guano deposit located on the Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile, was studied by single-crystal low-temperature (200 K) XRD, R = 2.42 %. The compound I is orthorhombic, space group P212121; a = 19.484(3), b = 7.2136(10), c = 11.999(4) Å, V = 1686.5(7) Å3, Z = 4. The crystal structure of I contains zig-zag chains of the corner-sharing Cu(1)-centered octahedra running along the a axis and isolated Cu(2)- centered octahedra connected with the chains via 1,2,4-triazolate anions. This structural fragment is close to that found in the mineral chanabayaite, Cu2(N3C2H2)2Cl(NH3, Cl, H2O, ⌀)4. In contrast to Na-free chanabayaite, in the structure of I Na cations occupy Na(H2O)6 octahedra connected via common edges to form chains parallel to the chains of Cu(1)-centered octahedra. I is the second natural compound, after chanabayaite, with 1,2,4-triazolate anions N3C2H2 - and is assumed to be a protophase of chanabayaite; the latter was presumably formed as a result of Na and Cl leaching and dehydration of I. [ABSTRACT FROM AUTHOR] |
