Standard molar enthalpy of formation at 298.15 K of the β-modification of molybdenum ditelluride☆

Abstract Fluorine-combustion calorimetry of a high-purity sample of molybdenum ditelluride has yielded the standard molar enthalpy of formation: Δ f H m o MoTe 2 , cr, β, 298.15 K) = −(84.2 ± 4.6) kJ·mol −1 . At 298.15 K, the enthalpy of the hypothetical β-to-α transition in MoTe 2 is approximately −6 kJ·mol −1 . The present result for Δ f H m o (MoTe 2 ) has been combined with literature values for the decomposition pressures of MoTe 2 to yield Δ f H m o (Mo 3 Te 4 , cr, 298.15 K) = −(185 ± 10) kJ·mol −1 . Our previously published Δ f H m o (TeF 6 ) ( Trans. Faraday Soc. 1966 , 62, 558) has been revised slightly to −(1371.8 ± 1.8) kJ·mol −1 .