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Arsenosiloxane: Bildung und Zerfall von Trialkylsilyl‐arsenaten und ‐arseniten
Author(s) -
Baier Michael,
Bissinger Peter,
Schmidbaur Hubert
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921250214
Subject(s) - chemistry , trimethylsilyl , octahedron , tris , thermal decomposition , arsenate , medicinal chemistry , polymer chemistry , crystal structure , inorganic chemistry , arsenic , crystallography , organic chemistry , biochemistry
Arsenosiloxanes: Formation and Decomposition of Trialkylsilyl Arsenates and Arsenites Tris(trialkylsilyl) arsenates(V) are prepared from silver arsenate(V) and chlorotrialkylsilanes or from arsenic acid and hexaalkyldisilazanes. The triethylsilyl ester 1b is stable, but the trimethylsilyl ester 1a undergoes condensation at ambient temperature to give hexamethyldisiloxane and trimethylsilylpolyarsenates(V), including tetrakis(trimethylsilyl) diarsenate(V) ( 4a ). According to an X‐ray crystal structure determination of 4a (triclinic, space group P 1) centrosymmetrical dimers are present containing two edge‐sharing AsO 6 octahedra with apex‐bridging by two AsO 4 tetrahedra. 1a is converted into the salt [(Me 3 SiO) 4 As] + CF 3 SO 3 − the cation of which is believed to be a component of the reaction chain. There is also evidence by mass spectrometry for the existence of (Me 3 SiO) 5 As ( 5 ). — Tris(trimethylsilyl) arsenite(III) ( 6 ) is prepared from AsCl 3 and NaOSiMe 3 . With modified stoichiometry, side reactions give also the byproducts Cl 2 AsOSiMe 3 , ClAs(OSiMe 3 ) 2 , Cl 2 AsOAsCl 2 , Cl 2 AsOAsCl(OSiMe 3 ), O[AsCl(OSiMe 3 )] 2 , and cyclic chloroarsenosiloxanes ( 12, 13 ).