Vaporization Studies of Dysprosium Trichloride, Tribromide, and Triiodide

Abstract

The vapor pressures of DyCl3, DyBr3, and DyI3 were measured by the torsion method, and the following selected equations were derived in the covered temperature ranges. DyCl3: log(p/kPa) = 9.31 ± 0.30 − (12523 ± 300)(K/T), (924−1214 K). DyBr3: log(p/kPa) = 11.47 ± 0.30 − (14344 ± 300)(K/T), (878−1151 K). DyI3: log(p/kPa) = 11.34 ± 0.20 − (13800 ± 200)(K/T), (889−1157 K). Treating by second- and third-law methods the obtained results, the standard sublimation enthalpies, Δsub H°(298 K) = 283 ± 5, 289 ± 6, and 282 ± 4 kJ mol-1 for DyCl3, DyBr3, and DyI3, respectively, were determined.

Vapor Pressure and Sublimation Enthalpies of Holmium Trichloride, Tribromide, and Triiodide

“…However, we are doubtful to use "tout court" in our calculation, the ∆fef associated with the sublimation of HoCl 3 [values derivable from Kudin's vapor pressure data and the corresponding third-law ∆ sub H°(298 K) because, unfortunately, the thermodynamic function values are not reported in their work], but the comparison of our thirdlaw enthalpy with that proposed by Kudin et al 2 consolidates the suspicion that the fef reported by Pankratz 19 for some trichlorides of lanthanides may be not correct, suspicion advanced in our previous study on dysprosium trichloride. 11 On this basis, our third-law enthalpy could be considered an upper value and, therefore, giving double weight to the second-law enthalpy value, we propose as a standard sublimation enthalpy of HoCl 3 the value of ∆ sub H°(298 K) ) 296 kJ‚mol -1 , with an estimated error of (10 kJ‚mol -1 .…”

“…The vapor pressures above HoI 3 were measured by the Knudsen method by Hirayama et al 9 and mass spectrometrically by Kaposi et al 10 By continuation of our research program on the study of the vaporization of lanthanide trihalides (Brunetti et al 11,12 and Villani et al 13,14 ), the total vapor pressures of holmium trichloride, tribromide, and triiodide were measured. The obtained data were treated by the second-and third-law methods to derive the corresponding standard sublimation enthalpies of these compounds.…”

Quantum Chemical Studies of Neutral and Ionized DyX, DyX2, and DyX3 Species (X = F, Cl, Br, I) and the Implications for the Mass Spectra of Gaseous DyX3

“…The vaporization of dysprosium halides has been investigated by different methods. Brunetti et al6 and Kapala et al7 have published a comparison of thermodynamic data reported in the literature. Recently, the vaporization thermodynamics of DyCl 3 ,7,8 DyBr 3 ,9 and DyI 3 10 were investigated by means of Knudsen effusion mass spectrometry using different equipment and experimental conditions.…”

Vapor Pressures and Standard Sublimation Enthalpies for Thulium Trichloride, Tribromide, and Triiodide

“…The value is in agreement within the associated error with those reported in the literature (292, 1 298, 2 and 291 ( 5 3 ) kJ‚mol -1 . Like TmCl 3 , also for TmBr 3 some standard sublimation enthalpy values were calculated by the third-law treatment of the vapor pressures at (900, 1000, and 1100) K. The fef for solid TmBr 3 (reported in Table 6) necessary for this calculation was estimated by us from the corresponding values for other solid tribromides of heavy lanthanides and in particular from HoBr 3 , 21 from those for TbBr 3 15 and ErBr 3 16 (both calculated from their S°(298 K) and the experimental temperature dependence of their heat capacities), and from DyBr 3 13 (derived from third-law treatment of the vapor-pressure data). The difference between the lowest fef values (HoBr 3 ) and the highest ones (DyBr 3 ), equal to about 3 kJ‚mol -1 , is practically constant in the temperature range (900 to 1100) K. For gaseous TmBr 3 are used the fef reported by Pankratz 22 and those reported in the Gietmann's work.…”

“…5 The mass spectrum of the vapor over TmI 3 was determined at 913 K, 6 and this was very similar to those of other triiodides of the rare-earth elements. 7 This work is part of a continuing systematic study [8][9][10][11][12][13][14][15][16] carried out in order to obtain accurate measurements of the vapor pressures of rare-earth trihalides and to derive their standard sublimation enthalpies. In particular, the aim of the present paper was to determine the standard sublimation enthalpies of thulium trichloride, tribromide, and triiodide measuring their vapor pressures.…”