The reaction of organic dihalides with organyltelluride (RTe–) anions : telluronium salts and charge-transfer complexes

Abstract

The reaction of NaTeR (R =p-EtOC₆H₄ or Ph) with organic dihalides (CH₂)_nX₂(n= 1–4) affords telluronium salts (n= 3 or 4; X =Cl or Br) the nature of which is discussed. For n= 1 (X = Br or I) the products are formulated as charge-transfer complexes of stoicheiometry (RTe)₂CH₂·CH₂X₂. For n= 2, elimination of ditelluride occurs with formation of an alkene. The compound NaTeR is shown to be an effective dehalogenating agent for vic-dihalides. Some ¹²⁵Te Mössbauer data are discussed and it is suggested that the unusually low value of Δ(7.58 mm s^–1) for (p-EtOC₆H₄Te)₂CH₂·CH₂Br₂ relates to removal of 5p-electron density from the spare-pair orbital via the charge-transfer interaction. The related di-iodomethane complex gives a solid-state e.s.r. signal. Mass spectroscopic data are discussed and these support the formulations proposed.