JSC Solikamsk Magnesium Plant, Solikamsk, Russia

P. G. Detkov, Board Member, Candidate of Technical Sciences, e-mail: p.detkov@yandex.ru

Independent Expert, Moscow, Russia

D. V. Drobot, Doctor of Chemical Sciences, e-mail: dvdrobot@mail.ru

In 1905 the Austrian scientist Carl Auer von Welsbach published a report that the element ytterbium, discovered by the Swiss scientist Marignac in 1878, is not homogeneous, but consists of at least two elements. In articles published in 1906 and 1907, the scientist gave a more detailed description of his research. Carl Auer von Welsbach wrote that the results of his research clearly indicate that ytterbium consists of two elements, a detailed description of which he promises to provide soon. At the meeting of the Imperial Academy of Sciences in Vienna on December 19, 1907, the scientist indicated the detailed spectroscopic characteristics of these two elements. Carl Auer von Welsbach suggested giving one element the name “Aldebaranium” and the other “Cassiopeium”. The scientist determined the atomic mass of Aldebaranium — 172.90 and Cassiopeium — 174.24. On November 14, 1907, at a meeting of the Paris Academy of Sciences, a report was presented by French chemist Georges Urbain entitled “A new element lutetium obtained from ytterbium of Marignac”, in which the scientist reported that he had succeeded in decomposing ytterbium into two new elements, for one of them he suggested the name “Neoytterbium” and the name “Lutetium” for the other. For Lutetium, the French chemist published a table that included 34 spectral lines. Urbain determined that the atomic mass of Neoytterbium should be about 170, and the atomic mass of Lutetium should not be higher than 174. Subsequently, Georges Urbain insisted on his priority in discovering new elements, since his presentation at the meeting of the Paris Academy of Sciences was 44 days earlier than the report of Carl Auer von Welsbach. The issue of priority in the discovery of new elements was considered at a meeting of the International Committee on Atomic Weights. One of the four members of this committee was Georges Urbain, which gave him an exceptional position to substantiate facts. The Committee accepted Urbain’s arguments and in January of 1909 published conclusion that, since Urbain has a clear priority, his nomenclature should be preferred. In 1924 the German Committee on Atomic Weights published a report on the consideration of the priority in the discovery of Lutetium/Cassiopeium. The Committee emphasized that the final name of a new element should be given not at a time when there are only signs of its existence, but from the moment when its detailed characteristics are obtained. The German Committee disagreed with the decision of the International Committee on Atomic Weights and chose the name “Cassiopeium”, given by Carl Auer von Welsbach. The name “Cassiopeium” was used in Germany, Austria, and the Scandinavian countries until about the mid-1950s. However, Lutetium, which is internationally recognized, gradually replaced Cassiopeium in these countries. It is currently believed that Lutetium was discovered by Georges Urbain and Carl Auer von Welsbach simultaneously and independently of each other.

1. Detkov P. G., Drobot D. V. History of the discovery of rare earth elements. Praseodymium and neodymium. Tsvetnye Metally. 2023. No. 3. pp. 82–85.
2. Auer von Welsbach C. Vorlaüfiger Bericht über die Zerlegung des Ytterbiums in seine Elemente. Anzeiger der kaiserlichen Akademie der Wissenschaften. Mathematisch-naturwissenschaftliche Klasse. 1905. No. 10. pp. 122.
3. Auer von Welsbach C. Über die Elemente der Yttergruppe (1.Teil). Sitzungsberichte der kaiserlichen Akademie der Wissenschaften. Mathematisch-naturwissenschaftliche Klasse. 1906. B. 115. Abt. IIb. pp. 737–747.
4. Komissarova L. N., Shackiy V. M., Pushkina G. Ya. et al. Compounds of rare earth elements. Carbonates, oxalates, nitrates, titanates. Moscow : Nauka, 1984. 235 p.
5. Auer von Welsbach C. Bemerkungen uber die Anwendung der Funkenspectren bei Homogenitätsprüfungen. Justus Liebigs Annalen der Chemie. 1907. B. 351. pp. 458–466.
6. Auer von Welsbach C. Die Zerlegung des Ytterbiums in seine Elemente. Anzeiger der kaiserlichen Akademie der Wissenschaften. Mathematisch-naturwissenschaftliche Klasse. 1907. No. 27. pp. 488–489.
7. Auer von Welsbach C. Die Zerlegung des Ytterbiums in seine Elemente. Sitzungsberichte der kaiserlichen Akademie der Wissenschaften. Mathematischnaturwissenschaftliche Klasse. 1907. B. 116. Abt. IIb. pp. 1425–1469.
8. Auer von Welsbach C. Die Zerlegung des Ytterbiums in seine Elemente. Monatshefte für Chemie und verwandte Teile anderer Wissenschaften. 1908. Bd. 29. pp. 181–225.
9. Urbain G. Un nouvel élément: le lutécium, résultant du dédoublement de l’ytterbium de Marignac. Comptes rendus hebdomadaires des séances de l’Académie des Science. 1907. Vol. 145. pp. 759–761.
10. Urbain G. Sur le lutécium et le néoytterbium. Comptes rendus hebdomadaires des séances de l’Académie des Science. 1908. Vol. 146. pp. 406–408.
11. Clarke F. W., Ostwald W., Thorpe T. E., Urbain G. Report of the International Committee on Atomic Weights. The Journal of the American Chemical Society. 1909. Vol. 31, No. 1. pp. 1–6.
12. Wenzel F. Zur Spaltung des Ytterbiums. Zeitschrift fu.r Anorganische Chemie. 1909. B. 64. pp. 119–120.
13. Auer von Welsbach C. Zur Zerlegung des Ytterbiums. Monatshefte für Chemie und verwandte Teile anderer Wissenschaften. 1909. B. 30. pp. 695–700.
14. Urbain G. Lutetium und Neoytterbium oder Cassiopeium und Aldebaranium. Zeitschrift für Anorganische Chemie. 1910. B. 68. pp. 236–242.
15. Hahn O., Honigschmid O., Bodenstein M., Meyer R. J. Vierter Bericht der Deutschen Atomgewichts-Kommission. In der Zeit vom Juli 1922 bis November 1923 veroffentliche Abhandlungen. Berichte der deutschen chemischen Gesellschaft. 1924. B. 57. No. 1. pp. I–XXXVI.
16. Urbain G. Sur un nouvel élément qui accompagne le lutécium, et le scandium dans les terres de la gadolinite: le celtium. Comptes rendus hebdomadaires des séances de l’Académie des Science. 1911. Vol. 152. pp. 141–143.
17. Hansen H. M., Werner S. On Urban’s celtium lines. Nature. 1923. Vol. 111. pp. 461.
18. Riesenfeld E. H. Lehrbuch der anorganischen Chemie. 2. Auflage. Wien : Franz Deuticke, 1939. 706 p.
19. Sicius H. Seltenerdmetalle: lanthanoide und dritte nebengruppe. Wiesbaden : Springer Fachmedien, 2015. 74 p.
20. Polyakov E. G., Nechaev A. V., Smirnov A. V. Metallurgy of rare earth metals. Мoscow : Metallurgizdat, 2018. 731 p.
21. Motylyaev A. Lutetium: facts. Khimiya i zhizn. 2021. No. 11. pp. 20–25.
22. Faust A. Medical application of rare earth compounds. Rare Earth Chemistry. Edited by Pottgen R., Jüstel T., Strassert C. A. Berlin : De Gruyter, 2020. pp. 439–452.
23. Morgan K. A., Rudd S. E., Noor A., Donelly P. S. Theranostic nuclear medicine with Gallium-66, Lutetium-177, Copper-64/67, Actinium-225, and Lead-212/203 radionuclides. Chemical Reviews. 2023. Vol. 123. Iss. 20. pp. 12004–12035. DOI: 10.1021/acs.chemrev.3c00456
24. Niu T., Fan M., Lin B., Gao F. et al. Current clinical application of lutetium-177 in solid tumors (Review). Experimental and Therapeutic Medicine. 2024. Vol. 27, Iss. 5. 225. DOI: 10.3892/etm.2024.12514
25. Golan H., Tutsunov K. K., Volkov O. Sistematic review of the first 40 cases of 177Lu-PSMA therapy in the treatment of non-prostatic cancer. Anticancer Research. 2024. Vol. 44, Iss. 6. pp. 2297–2305. DOI: 10.21873/anticanres.17037