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.

In the asymmetric unit of the title salt, C 3 H 9 S + ÁCH 2 B 11 FI 10 N À or (CH 3 ) 3 S[1-H 2 N-6-F-closo-1-CB 11 I 10 ], both ions lie in general positions. The anion is perfectly ordered and so the positions of the C-NH 2 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-CB 11 } cluster.

Maik Finze and Guido J. Reiss Comment
Monocarba-closo-dodecaborates with amino groups that are bonded to the cluster carbon or boron atoms are potential building blocks for a broad range of applications (Körbe et al., 2006). The properties of the amino group are strongly influenced by (i) the other substituents of the {closo-1-CB 11 } cluster (Jelínek et al. 1986;Srivastava et al. 1996;Finze et al., 2007;Finze, 2007) and (ii) the type of cluster atom that it is bonded to (Finze, 2009 Lewis-acidity at the mercury atom no coordination of a third ligand was observed (Himmelspach et al., 2012). Similarly, a much lower electron density at the amino group is found for halogenated {1-H 2 N-closo-1-CB 11 } clusters in comparison to [1-H 2 N-closo-1-CB 11 H 11 ] -: The non-halogenated anion is easily protonated to yield 1-H 3 N-closo-1-CB 11 H 11 (pK a = 6.0)  Lavrentiev, 1993;Forrester et al., 1995;Park et al., 2005).

Refinement
All hydrogen atoms of the CH 3 groups were refined using a riding model with the U iso (H) set to 1.5U eq (C). The coordinates of the two hydrogen atoms at the nitrogen atom were refined unrestrictedly together with one refined common U iso value. Anisotropic displacement parameters of all non-hydrogen atoms were also refined unrestrictedly.

Computing details
Data The structure of the asymmetric unit, showing 50% probability displacement ellipsoids. Hydrogen atoms are shown as spheres of arbitrary radius.
Trimethylsulfonium 1-amino-6-fluoro-2,3,4,5,7,8,9,10,11,12-decaiodo-1-carba-closo-dodecaborate  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.