Synthesis of Five‐ and Six‐Coordinate Tris(pentafluoroethyl)fluorosilicates

The research area of perfluoroalkylsilanes is still in its infancy. Although there are already many examples of difluorotriorganylsilicates, the first example of a completely characterized trifluorotriorganylsilicate is presented, the dianion [Si(C 2 F 5 ) 3 F 3 ] 2− . The strongly electron‐withdrawing influence of the pentafluoroethyl groups appears to be a fundamental cause of the stability of this compound. This dianion is also the first structurally characterized example of a tris(pentafluoroethyl)silicon compound. The synthesis and complete characterization of [PPh 4 ] 2 [Si(C 2 F 5 ) 3 F 3 ] and [PPh 4 ][Si(C 2 F 5 ) 3 F 2 ] along with the precursor [H(OEt 2 ) 2 ][Si(C 2 F 5 ) 3 F 2 ] was achieved from SiCl 4 and LiC 2 F 5 .