Isotopic studies by vibrational spectroscopy of the tellurium–carbon bond in diaryltellurium dihalides

Abstract

Isotopically pure (¹²⁶Te and ¹³⁰Te) samples of Ph₂TeCl₂, Ph₂TeBr₂, and (p-MeC₆H₄)₂TeBr₂ have been prepared. Examination of the low-frequency i.r. spectra (with confirmation from Raman spectra) enables definitive assignments of tellurium–carbon stretching vibrations to be made and also establishes this description of these vibrational modes to be physically realistic. The symmetric (Te–Cl) and Te–C) stretching vibrations of Ph₂TeCl₂ are coupled but ν(Te–Br) in Ph₂TeBr₂ is a relatively pure vibration.