VIBRATIONAL FREQUENCIES, VAPOR-PRESSURE AND AN ASSESSMENT OF THE THERMODYNAMIC PROPERTIES OF DIMETHYL TELLURIDE

The IR and Raman spectra of gaseous and liquid dimethyl telluride, Te( CH3)(2), have been recorded and a complete assignment has been made. T he thermodynamic functions of gaseous dimethyl telluride have been cal culated using the assigned vibrational frequencies and additional info rmation, such as structural information and the energy barrier hinderi ng internal rotation of the methyl groups. The vapour pressure of dime thyl telluride has been measured from 267 to 369 K and can be represen ted 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, Del ta(vap) H-m(o)(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 d imethyl telluride in the temperature range 298.15 to 1500 K.