화학공학소재연구정보센터
Journal of Chemical Thermodynamics, Vol.27, No.8, 921-926, 1995
Thermochemistry of (Germanium Plus Tellurium) .2. Molar Enthalpies of Dissociation of Bonds in GeTe(G), Gete2(G), and Ge2Te2(G)
Well established thermochemical values yield the enthalpy of dissociation of GeTe(g) : D-m(o)(GeTe) = (396.7 +/- 3.3) kJ . mol(-1) at T --> 0. The same quantity estimated from spectroscopic measurements is uncertain. The mean enthalpy of dissociation [D-m(o)] of the Ge-to-Te bonds in GeTe2(g) is (303 +/- 4) kJ . mol(-1), and D-m(o)(Te-GeTe)=(210 +/- 8) kJ . mol(-1). Thus, D-m(o)(Te-GeTe)/D-m(o)(GeTe) approximate to 0.5, a relation found earlier for other diatomic and triatomic molecules of the chalcogenides of Group 14. In the cyclic compound Ge2Te2(g), the [D-m(o)] of the four Ge-to-Te bonds is (224 +/- 3) kJ . mol(-1). These values of D-m(o)(GeTe) and [D-m(o)] follow the progression expected for nominal triple, double, and single G-to-Te bonds in GeTe(g), GeTe2(g), and Ge2Te2(g), respectively.