Syntheses of alkoxotellurium (VI) fluorides, (RO)xTeF6 –x: importance of intramolecular electronic effects on the value of x

Abstract

Under similar experimental conditions, tellurium hexafluoride reacts with the alcohols ROH (R = Me, Et, CH₂CHCH₂, ICH₂CH₂, MeC(O)CH₂CH₂, MeOC(O) CH₂CH₂, Br[CH₂]₃, PhCH₂CH₂, PhOCH₂CH₂, and Bu^tOCH₂CH₂) to produce the dialkoxotellurium (VI) tetrafluoride, TeF₄(OR)₂; with R = CF₃CH₂, CICH₂CH₂, (CICH₂)₂CH, BrCH₂CH₂, and MeSCH₂CH₂ to produce the trialkoxotellurium (VI) trifluorides, TeF₃(OR)₃; and with R = NCCH₂CH₂, MeOCH₂CH₂, and EtOCH₂CH₂ to produce a mixture of both the di- and tri-alkoxo-compounds. The importance of Taft constants, steric effects, and neighbouring group participation in explaining these differences is discussed.