Synthesis and Structural Characterization of Graphite-Like [(Me3Sn)3O]Cl

Abstract

In our investigations on weakly coordinating cations and anions, we were interested in the properties of the sterically demanding oxonium cation [(Me3Sn)3O]‡ . We have already isolated tris(trimethylsilyl)methylaluminum compounds which exhibit weak cation ± anion interactions. In the anions of both [Ag(toluene)3]‡[{[(SiMe3)3C]2Al2F5}2Li]ÿ and [AlF2(thf)4]‡[{(SiMe3)3C}2Al2F5]ÿ the fluorine atoms bridge the aluminum atoms. Weak ionic interactions are the result of the efficient shielding of the anionic centers by the tris(trimethylsilyl)methyl ligands.[1] Dehnicke et al. have already described trimethylstannylsubstituted ammonium salts that exhibit an interesting ionic arrangement. In [NH2(SnMe3)2][SnMe3Cl2], the chlorine atoms bridge two tin atoms and one hydrogen atom, which leads to a symmetrical three-dimensional lattice.[2, 3] Interactions of alkyltin compounds with Lewis bases are not rare. The tin atoms in SnF4 and Me2SnF2 as well as in the [SnCl6]2ÿ dianion are surrounded by their ligands in an octahedral arrangement.[4, 5] There is an almost trigonal-bipyramidal configuration of tin and oxygen in Me3SnN(SO2Me)2 ́ Me3SnOH, whereby the oxonium ion [(Me3Sn)2OH]‡ is formed.[6] The synthesis and properties of [(Me3Sn)3O]I have already been discussed by Harada, however, without a structural investigation of this compound.[7] H3O‡ and the cation of the Meerwein salt are the best known oxonium ions. Our work is directed to the synthesis and the structural characterization of the oxonium salt [(Me3Sn)3O]Cl (1). This compound was synthesized by refluxing (Me3Sn)2O and Me3SnCl in THF for 12 h. After concentration of the solution and storage at ÿ23 8C, 1 precipitated as colorless crystals [Eq. (1)]. Compound 1 was investigated by single-crystal X-ray structural analysis, NMR and IR spectroscopy as well as mass spectrometry. Compound 1 is also accessible by the treatment of Me3SnCl with Li2O in refluxing THF [Eq. (2)].

Cite this paper

@inproceedings{Cl1999SynthesisAS, title={Synthesis and Structural Characterization of Graphite-Like [(Me3Sn)3O]Cl}, author={Graphite-Like Cl and Bodo R{\"a}ke and Peter M{\"{u}ller and Herbert W Roesky}, year={1999} }