Thermodynamics of the Evaporation of Yttrium Trichloride in the Form of YCl3 and Y2Cl6 Molecules

Gas-Phase Thermochemistry of MX3 and M2X6 (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

“…The TCS 14 tabulated YCl3 heat of formation is 3.6 -4.0 kcal/mol more positive than our predicted values. In contrast, the most recent experimental estimate of Osina and co-workers 16 is 2.8 -3.2 kcal/mol more negative than our ΔH f °(0 K) and ΔH f °(298.15 K) calculated values. Our predicted 0 K atomization enthalpies are listed in Table 6.…”

“…This deviation is within the experimental uncertainty of ±2.9 kcal/mol. The most recent ΔH f °(0 K) and ΔH f °(298.15 K) Y2Cl6 experimental estimates of Osina and co-workers 16 turned out to be 5.9 -6.8 kcal/mol more negative compared to our predicted values. The available ΔH f °(298.15 K) TCS 14 estimate was found ca.…”

“…Calculated 0 K Dissociation Enthalpies (kcal/mol) Cl 6 experimental estimates of Osina and co-workers16 turned out to be 5.9−6.8 kcal/mol more negative compared to our predicted values. The available ΔH f °(298.15 K) TCS14 estimate was found as ca.…”

“…This is unlike to what was observed for Sc dimers where the (n-1)s 2 p 6 Br/I electron correlation shifted the Sc2Br6 and Sc2I6 dissociation enthalpies in opposite directions. -401.5±2.9 16 -366.0±8.0 14 -401.4±2.9 16…”

“…The thermal constants of substances (TCS) online database developed at the Glushko Thermocenter includes gas-phase data on the ScF 3 , ScCl 3 , ScBr 3 , Sc 2 Cl 6 , YF 3 , YCl 3 , and Y 2 Cl 6 species, although many of them are based on the experimental measurements of limited accuracy. A series of new density functional theory (DFT) and ab initio calculations performed on par with a critical analysis of the available experimental and theoretical structural data on the scandium/yttrium trihalides and their dimers resulted in refined values of the formation enthalpies of ScF 3 –ScBr 3 and Y 2 Cl 6 and afforded, for the first time, accurate thermochemistry of ScI 3 , YBr 3 , Y 2 Br 6 , YI 3 , Y 2 I 6 , and Y 2 F 6 . , These data were then incorporated in an IVTANTERMO database. , However, because many of the original data forming a basis of an IVTANTERMO database are based on the half-century-ago experimental measurements with custom-built techniques, a separate independent source of information is of paramount importance.…”