Extended Data Table 1 Comparison of computed 29Si chemical shifts for free gas-phase halosilylium ions and their adducts with the counteranion [HCB11H5Br6]− at different levels of theory.a

From: Isolation of halogen-substituted silylium ions

 

1c/PBE0

4c/PBE0

1c/PBE0

2c/PBE0

4c/PBE0

4c/PBE0c

exp.

coord.b

−

−

A−

A−

A−

A−

 

iPr2FSi+

178.1

173.4

76.6

67.4

67.7

47.0

47.0

iPr2ClSi+

263.2

253.8

105.5

93.1

94.2

73.4

74.3

iPr2BrSi+

304.0

272.2

122.6

99.8

100.0

79.3

79.3

iPr2ISi+

358.2

286.8

141.9

102.4

102.6

81.9

78.8

  1. aChemical shifts in ppm relative to tetramethylsilane.
  2. bGas-phase vs. adduct with the carborate counteranion (conformer A was used; see Supplementary Fig. 12).
  3. cReferenced to tetramethylsilane indirectly via the secondary standard iPr2FSi+ to correct for systematic errors. This leads to a constant low-frequency shift by ca. –20.7 ppm.
Back to article page