Tris(trifluoromethyl)tellurate(II), [Te(CF 3) 3] −, the dimeric bis(trifluoromethyl)chlorotellurate(II), [(CF 3) 2TeCl] 22−, and bis(trifluoromethyl)iodate(I), [I(CF 3) 2] −: the first hypervalent alkyl [10-Te-3] and [12-Te-4] species and a novel [10-I-2] compound

Abstract

The reactions of (CH 3) 3SiCF 3/[(CH 3) 4N]F with Te(CF 3) 2 and CF 3I, respectively in THF or glyme at −60 °C yield [(CH 3) 4N][Te(CF 3) 3] and [(CH 3) 4N][I(CF 3) 2]. Both salts were isolated as colorless and extremely reactive solids. The NMR spectra are discussed; the 1J F,C coupling constants of the CF 3 groups of the linear CF 3TeCF 3 and CF 3ICF 3 units exhibit extremely high values. Under comparable conditions and also in CH 2Cl 2 at ambient temperature, salts with the anion [(CF 3) 2TeCl] − are formed from the reactions Te(CF 3) 2, [TAS][(CH 3) 3SiF 2]/(CH 3) 3SiCl and [PNP]Cl, respectively. The crystal structure (triclinic; P-1) of [TAS] 2[(CF 3) 2Te(μ-Cl) 2Te(CF 3) 2] exhibits dimeric chloro-bridged TeCl units.