Trimethyl­sulfonium 1-amino-6-fluoro-2,3,4,5,7,8,9,10,11,12-decaiodo-1-carba-closo-dodeca­borate

In the asymmetric unit of the title salt, C₃H₉S⁺·CH₂B₁₁FI₁₀N^- or (CH₃)₃S[1-H₂N-6-F-closo-1-CB₁₁I₁₀], both ions lie in general positions. The anion is perfectly ordered and so the positions of the C-NH₂ vertex and the fluorine substituent are clearly assigned. The relatively short C-N bond length may be inter­preted in terms of a very electron deficient {closo-1-CB₁₁} cluster.

2,3,5,6-Tetra­fluoro-1,4-bis­(trimethyl­sil­yl)benzene

The asymmetric unit of the title compound, C₁₂H₁₈F₄Si₂, contains two independent mol­ecules, both lying on inversion centers. The C_arene-Si distances are significantly longer than in the analogous non-fluorinated compound. The packing of the mol­ecules results in a herringbone motif in the ac plane.

Ammonium 4,4-difluoro-1,3,2-dithia­zetin-2-ide 1,1,3,3-tetra­oxide

The asymmetric unit of the title compound, NH₄⁺·CF₂NO₄S₂⁻, consists of two crystallographically independent ammonium cations and two 4,4-difluoro-1,3,2-dithia­zetin-2-ide 1,1,3,3-tetra­oxide anions all located in general positions. The S—C—S—N rings of both crystallographically independent anions are almost planar, with the N atom bent out of the plane by 9.82 (5) and 12.82 (4)°. The structure was determined from a crystal twinned by inversion, with refined components in the ratio 0.73 (4):0.27 (4). Anions and cations are connected via hydrogen bonds (N—H...O and N—H...N) to form a three-dimensional framework. This framework is composed of two different layers parallel to the ab plane, which are built by the ammonium cations on the one hand and the complex cyclic anions on the other.