Anton Preisinger

Die Kristallstruktur von Na2S · 5H2O, Na2Se · 5H2O und Na2Te · 5H2O

Crystals of Na^S · 5 H 2 0 , Na^Se · 5 H 2 0 and Na^Te · 5 H 2 0 have the la t t ice parameters α = 6.476 Ä, a — 6.56, Ä, α = 6.735 A, ft = 12.545 A, ft = 12.873 A, ft = 13.469 Α, c = 8.656 A, c = 8.912 A, C = 9.21, Α, space g roup Cmcm—DJjJ, Ζ = 4. The s t ruc tu re has been determined by twodimensional Fourier and (F0—Fc) syntheses along [001], [010] and [100]. One N a j ion is surrounded octahedral ly b y six wa te r molecules and one N a n ion is surrounded by four water molecules and one S ion forming a quadra t ic pyramid. The NaT—H20 oc tahedra form chains which are connected to layers by the pyramida l coordinated N a n ions. These layers are l inked t o each other by hydrogen bonds, Ο—Η · · · S and Ο—Η · · · Se and Ο—Η · · · Te, respectively. Auszug Na^S · 5H 2 0, NeUjSe · 5H 2 0und Na 2Te · 5H2O KristalIe besitzen die G i t t e rkons tan ten ο = 6,475 A, a = 6,56, A, a = 6,735 A, b = 12,54s A, ft = 12.873 A, ft = 13,469 A, c = 8,655 A, c = 8,912 A, c = 9,21, A, die R a u m g r u p p e Cmcm—Ζ = 4. Die S t r u k t u r wurde mi t te ls zweidimensionalen Fourierund (Fa—F^-Synthesen parallel [001], [010] u n d [100] bes t immt . E in N a r I o n ist oktaedr isch von 6 H 2 0-Molekü len und ein N a n I o n von 4 H 20-Molekülen und einem SIon in F o r m einer quadra t i schen P y r a m i d e um* Daue rnde Adresse: Museo Bernard ino R ivadav ia , Buenos Aires, Argentinien.