Metallocenes of Samarium, Europium, and Ytterbium with the Especially Bulky Cyclopentadienyl Ligands C5H(CHMe2)4, C5H2(CMe3)3, and C5(CHMe2)5

✍ Scribed by Helmut Sitzmann; Thomas Dezember; Oliver Schmitt; Frank Weber; Gotthelf Wolmershäuser; Michael Ruck

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: German
• Weight: 119 KB
• Volume: 626
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/1521-3749(200011)626:11<2241::aid-zaac2241>3.0.co;2-0

✦ Synopsis

Octaisopropylmetallocenes of the lanthanoids Sm (1-Sm), Eu (1-Eu), and Yb (1-Yb) can be obtained easily from the diiodides of the rare earth elements. Like the hexa-(tert.-butyl)metallocenes 2-Sm, 2-Eu, and 2-Yb, they show no tendency towards coordination of donor solvent molecules or alkali salts. The decaisopropylmetallocenes 3-Sm, 3-Eu und 3-Yb have been synthesized from the metal and the free pentaisopropylcyclopentadienyl radical. The three europocenes 1-Eu, 2-Eu, and 3-Eu show fluorescence in day-light or under UV irradiation (336 nm). Crystalline 1-Eu and 2-Eu are bent sandwich complexes, whereas for the decaisopropyl derivative 3-Eu axial symmetry with parallel fivemembered rings has been observed.