Spectroscopic Investigation of Anhydrous Solutions of Europium Perchlorate and Europium Nitrate in N, N-Dimethylformamide

✍ Scribed by Jean-Claude G. Bünzli; Jean-Robert Yersin

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: German
• Weight: 459 KB
• Volume: 65
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19820650819

✦ Synopsis

Anhydrous solutions of Eu (c104)3 and Eu ( N o & 0.05 M in N , N-dimethylformamide (DMF) are investigated by means of conductometric measurements, vibrational spectroscopy, electronic absorption and emission spectra, and fluorescence lifetime determinations. Eu (C104)3 is completely dissociated and no inner-sphere interaction takes place between ClO; and Eu3+ ions. The solvated species Eu(DMF):+ has a C2,,-symmetry and x is probably equal to 8.

A more complicated situation occurs for Eu (N03)3r the solutions of which contain at least three different solvates; the predominant species is [Eu (N03)2 (DMF)x-4]+ ( ~8 0 % of the total Eu-concentration) and it is more stable than the mononitrato complex [Eu(N03) (DMF),-2]2+; the neutral complex Eu (N0,)3(DMF)x-6 is also present, as can be inferred from a high-resolution analysis of the 5DO+ 7F0 emission band. The absence of emission from the excited 'D1-level can be rationalized in terms of an efficient non-radiative deexcitation path through a vibrational mode of the DMF-molecules bonded to the central metal ion.

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