TY - JOUR
T1 - Formation and thermochemical properties of oxychlorides of niobium (Nb) and tantalum (Ta)
T2 - Towards the gas-phase investigation of dubnium (Db) oxychloride
AU - Chiera, Nadine M.
AU - Sato, Tetsuya K.
AU - Tomitsuka, Tomohiro
AU - Asai, Masato
AU - Suzuki, Hayato
AU - Tokoi, Katsuyuki
AU - Toyoshima, Atsushi
AU - Tsukada, Kazuaki
AU - Nagame, Yuichiro
N1 - Funding Information:
The authors express their gratitude to the crew of the JAEA tandem accelerator for their assistance in the course of these experiments. The present work was partly supported by JSPS Kakenhi Grant-in-Aid for Young Scientists (B) [grant number 20740152 ].
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/2/24
Y1 - 2019/2/24
N2 - The formation of NbOCl3 and TaOCl3 and their adsorption behavior on quartz surfaces was explored by applying an isothermal gas-chromatographic method. Trace amounts of short-lived Nb and Ta isotopes were used. Adsorption enthalpy values (ΔHads) at zero surface coverage of –ΔHads(NbOCl3) = 102 ± 4 kJ/mol and –ΔHads(TaOCl3) = 128 ± 5 kJ/mol were determined by analyzing the chromatographic behavior of the Nb and Ta complexes with a Monte-Carlo simulation method based on an adsorption–desorption kinetic model. By applying an empirical correlation, the experimental ΔHads values were successively related to the macroscopic standard sublimation enthalpy, ΔH°subl, as a measure of the volatility of each substance. The inferred sublimation enthalpies are in agreement with tabulated thermochemical values. Thus, the linear empirical correlation between ΔHads and ΔH°subl for metal-oxychlorides was updated with the inclusion of the present data. According to the predicted ΔH°subl(DbOCl3), a ΔHads(DbOCl3) value of 135 ± 2 kJ/mol was extrapolated. The future accomplishment of comparative studies with DbOCl3 under the same experimental conditions will provide valuable information on the volatility trend in Group-5 elements, together with an indication on the magnitude of relativistic effects on the electronic structure of dubnium.
AB - The formation of NbOCl3 and TaOCl3 and their adsorption behavior on quartz surfaces was explored by applying an isothermal gas-chromatographic method. Trace amounts of short-lived Nb and Ta isotopes were used. Adsorption enthalpy values (ΔHads) at zero surface coverage of –ΔHads(NbOCl3) = 102 ± 4 kJ/mol and –ΔHads(TaOCl3) = 128 ± 5 kJ/mol were determined by analyzing the chromatographic behavior of the Nb and Ta complexes with a Monte-Carlo simulation method based on an adsorption–desorption kinetic model. By applying an empirical correlation, the experimental ΔHads values were successively related to the macroscopic standard sublimation enthalpy, ΔH°subl, as a measure of the volatility of each substance. The inferred sublimation enthalpies are in agreement with tabulated thermochemical values. Thus, the linear empirical correlation between ΔHads and ΔH°subl for metal-oxychlorides was updated with the inclusion of the present data. According to the predicted ΔH°subl(DbOCl3), a ΔHads(DbOCl3) value of 135 ± 2 kJ/mol was extrapolated. The future accomplishment of comparative studies with DbOCl3 under the same experimental conditions will provide valuable information on the volatility trend in Group-5 elements, together with an indication on the magnitude of relativistic effects on the electronic structure of dubnium.
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U2 - 10.1016/j.ica.2018.10.032
DO - 10.1016/j.ica.2018.10.032
M3 - Article
AN - SCOPUS:85055902096
SN - 0020-1693
VL - 486
SP - 361
EP - 366
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
ER -