H. Oppermann et al., CALORIMETRY OF YTTRIUM TRIHALIDES AND YTT RIUM OXYHALIDES, Zeitschrift fur Naturforschung. B, A journal of chemical sciences, 52(3), 1997, pp. 305-310
The heats of solution of Yttrium, YOCL, YOBr, YOI, YCl3, YBr3, YI3 and
Y2O3 were determined in 4n HX. From those the enthalpies of formation
of Yttrium Trihalides YX3 and Yttrium Oxyhalides YOX at 298 K were de
rived: Delta(B)(0)(YCl3,f,298) = -240.4 +/- 0.6 kcal/mol, Delta H-B(0)
(YBr3,f,298) = -202.1 +/- 1.5 kcal/mol, Delta H-B(0)(YI3,f,298) = -147
.0 +/- 1.7 kcal/mol, Delta H-B(0)(YOClf,298) = -240.2 +/- 1.0 kcal/mol
, Delta H-B(0)(YOBrf,298) = -229.7 +/- 2.0 kcal/mol, Delta H-B(0)(YOIf
,298) = -208.8 +/- 2.0 kcal/mol.