Science. 1993 Jun 25;260(5116):1917-8. doi: 10.1126/science.260.5116.1917.
The crystal structure of a stable silyl cation, triethylsilylium, in the form of its tetrakis (pentafluorophenyl)borate salt [Et(3)Si(+) (C(6)F(5))(4)B(-)] (Et, ethyl) shows no coordination between cation and anion. The closest silicon-fluorine distance is greater than 4 angstroms. A toluene solvent molecule is close enough to cause some deviations from planarity at the silicon, but the silicon-toluene distance is well beyond the sum of the silicon and carbon covalent radii. The toluene molecule is essentially planar and undistorted, as expected if little or no positive charge has been transferred from silicon to toluene.
稳定的硅阳离子三乙硅烷基阳离子，以其四（五氟苯基）硼酸盐盐[Et（3）Si（+）（C（6）F（5））（4）B（-）]（Et，乙基）的形式的晶体结构显示阳离子和阴离子之间没有配位。最近的硅-氟距离大于 4 埃。一个甲苯溶剂分子足够接近导致硅原子的平面略有偏离，但硅-甲苯距离远远超过硅和碳共价半径的总和。甲苯分子基本上是平面的和未变形的，如果从硅到甲苯几乎没有或没有转移正电荷，则是可以预期的。
