Dimers of oxocentred [OCu4](6+) tetrahedra in two novel copper selenite chlorides, K[Cu3O](SeO3)(2)Cl and Na-2[Cu7O2] (SeO3)(4)Cl-4, and related minerals and inorganic compounds

作者：Kovrugin Vadim M; Colmont Marie; Mentre Olivier; Siidra Oleg I; Krivovichev Sergey V^*

来源：Mineralogical Magazine, 2016, 80(2): 227-238.

DOI：10.1180/minmag.2015.079.7.13

• crystal structure
• oxocentred tetrahedra
• lone electron pair
• stereoactivity
• euchlorine
• fedotovite
• prewittite
• burnsite

Two novel copper selenite chlorides, K[Cu3O](SeO3)(2)Cl (I) and Na-2[Cu7O2](SeO3)(4)Cl-4 (II), have been synthesized by the CVT method. Their crystal structures have been solved by direct methods and refined by least-squares techniques. I is triclinic, space group P (1) over bar, a = 7.6821(5), b = 8.1179(5), c = 8.7836(6) angstrom, alpha = 113.193(3), beta = 108.735(4), gamma = 98.245(4)degrees, V = 453.32(5) angstrom(3), R-1 = 0.0481 for 1210 unique reflections with F >= 4 sigma(F); II is triclinic, space group P (1) over bar, a = 7.4362(6), b = 8.3361(7), c = 9.1343(11) angstrom, alpha = 110.277(6), beta = 106.212(6), gamma = 105.158(4)degrees, V = 467.94(8) angstrom(3), R-1 = 0.0265 for 2498 unique reflections with F >= 4 sigma(F). The structures of I and II can be described in terms of dimers of copper oxocentred tetrahedra. In I, two (OCu4)(6+) tetrahedra share a common Cu center dot center dot center dot Cu edge to form the [O2Cu6](8+) dimer, whereas the structure of II is based upon two (OCu4)(6+) tetrahedra linked together by one common Cu atom resulting in the formation of the [O2Cu7](10+) dimer. A comparison with related minerals and inorganic compounds is given.

• 出版日期2016-4