Vibrational frequencies, vapour pressure and an assessment of the thermodynamic properties of dimethyl telluride

Abstract

The IR and Raman spectra of gaseous and liquid dimethyl telluride, Te(CH₃)₂, have been recorded and a complete assignment has been made. The thermodynamic functions of gaseous dimethyl telluride have been calculated using the assigned vibrational frequencies and additional information, such as structural information and the energy barrier hindering internal rotation of the methyl groups. The vapour pressure of dimethyl telluride has been measured from 267 to 369 K and can be represented by the equation log(p/Pa)= 27.8192 – 2673.64/(T/K)– 6.06377 log(T/K). The thermodynamic functions of condensed dimethyl telluride, necessary for the evaluation of the vapour pressure results, have been assessed from the available literature data. The enthalpy of vaporization, Δ_vapH^°_m(298.15 K)=(36.1 ± 1.0) kJ mol^–1, derived in this way, has been used to calculate the Gibbs energy of formation of gaseous dimethyl telluride in the temperature range 298.15 to 1500 K.