TY - JOUR
T1 - Heavy alkali metal tris(trimethylsilyl)silanides
T2 - A synthetic and structural study
AU - Jenkins, David M.
AU - Teng, Weijie
AU - Englich, Ulrich
AU - Stone, David
AU - Ruhlandt-Senge, Karin
PY - 2001/10/29
Y1 - 2001/10/29
N2 - Treatment of lithium tris(trimethylsilyl)silanide, Li(THF)3Si(SiMe3)3, with heavier alkali metal tert-butoxides yielded the alkali metal silanides MSi(SiMe3)3 (M = K, Rb, or Cs) in a simple, high-yielding, one-step procedure. Separation of the two solid reaction products was achieved by addition of crown ether, which also determines the formation of contact or separated ion pairs in the solid state. Here we report the synthesis and structural characterization of the contact ion K(18-crown-6)Si(SiMe3)3, 2, in addition to the separated [K(12-crown-4)2][Si(SiMe3)3], 1, [Rb(15-crown-5)2][Si(SiMe3)3], 3, and [Cs(18-crown-6)2][Si(SiMe3)3], 5. [Rb(18-crown-6)2][Si(SiMe3)3][Rb(18-crown-6)Si( SiMe3)3]2, 4, is a rare example where both contact and separated ions are observed in the solid state. The investigation of synthetic routes toward the target compounds also examined the previously published metalation of Si(SiMe3)4 with potassium tert-butoxide. This route proved to be temperamental: depending on reaction conditions and solvent systems, either adducts between product and unreacted starting material, namely, [{K(THF)Si(SiMe3)3}{KOtBu}3], 6, or the target compound KSi(SiMe3)3 was isolated. All compounds were characterized by X-ray crystallography and NMR spectroscopy.
AB - Treatment of lithium tris(trimethylsilyl)silanide, Li(THF)3Si(SiMe3)3, with heavier alkali metal tert-butoxides yielded the alkali metal silanides MSi(SiMe3)3 (M = K, Rb, or Cs) in a simple, high-yielding, one-step procedure. Separation of the two solid reaction products was achieved by addition of crown ether, which also determines the formation of contact or separated ion pairs in the solid state. Here we report the synthesis and structural characterization of the contact ion K(18-crown-6)Si(SiMe3)3, 2, in addition to the separated [K(12-crown-4)2][Si(SiMe3)3], 1, [Rb(15-crown-5)2][Si(SiMe3)3], 3, and [Cs(18-crown-6)2][Si(SiMe3)3], 5. [Rb(18-crown-6)2][Si(SiMe3)3][Rb(18-crown-6)Si( SiMe3)3]2, 4, is a rare example where both contact and separated ions are observed in the solid state. The investigation of synthetic routes toward the target compounds also examined the previously published metalation of Si(SiMe3)4 with potassium tert-butoxide. This route proved to be temperamental: depending on reaction conditions and solvent systems, either adducts between product and unreacted starting material, namely, [{K(THF)Si(SiMe3)3}{KOtBu}3], 6, or the target compound KSi(SiMe3)3 was isolated. All compounds were characterized by X-ray crystallography and NMR spectroscopy.
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U2 - 10.1021/om0102100
DO - 10.1021/om0102100
M3 - Article
AN - SCOPUS:0035969268
SN - 0276-7333
VL - 20
SP - 4600
EP - 4606
JO - Organometallics
JF - Organometallics
IS - 22
ER -