КРИСТАЛЛОХИМИЯ СЕЛЕНАТОВ С МИНЕРАЛОПОДОБНЫМИ СТРУКТУРАМИ. I. [А1(Н2О)6]2 (SО4)3(Н2О)4 - СЕЛЕНАТНЫЙ АНАЛОГ АЛУНОГЕНА

Abstract

Crystal structure of the sclcnatc analogue of alunogen, [А1(Н20)б]2(5еО4)з(Н2О)4 [monoclinic, P2\, a = 6.1521(6), b = 27.445(3), с = 7.5650(8) A, p. = 97.931 (8)°, V = 1265.1 (2) A3] has been solved by direct methods and refined to R, = 0.040 for 4670 reflections with \Fkkl\ > 4а|/гш|- Structure contains two symmetrically independent Al3t cations octahcdrally coordinated by six H2O molecules. Se atoms occupy three crystallographic sites and have tctrahcdral coordination typical for selcnates. The structure is based upon layers of octahedral complexes [А131ХН2О)б]3* and the (SelO4)'" and (Sc2O<i)2~ tctrahcdral ones linked by hydrogen bonds. The layers arc parallel to (010) and located at the levels of>> ~ 0.1 and у ~ 0.6. The (Sc3O4) ~ tctrahedra and «free» water molecules are in between the layers. [Al(H2O)6]2(ScO4)1(H2O)4 is not isostructural to alunogen but has similar unit cell and structural architecture.