Experimental and Theoretical Study of the Photophysics and Structures of Europium Cryptates Incorporating 3,3′-Bi-isoquinoline-2,2′-dioxide

✍ Scribed by Paula Gawryszewska; Oscar L. Malta; Ricardo L. Longo; Fabiana R. Goncalves e Silva; Severino Alves Jr.; Krzysztof Mierzwicki; Zbigniew Latajka; Marek Pietraszkiewicz; Janina Legendziewicz

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 279 KB
• Volume: 5
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.200400036

✦ Synopsis

Abstract

A detailed photophysical study of Eu⊂(biqO__~2~.2.2)(CF~3~SO~3~__)~2~⋅CH~3~CN⋅H~2~O (Eu⊂1) and two other types of cryptates incorporating three 3,3′‐biisoquinoline‐2,2′‐dioxide units has been performed. Structural crystallographic data of Eu⊂1, electronic structure calculations and theoretical models were used to obtain the intramolecular energy transfer rates and the appropriate set of rate equations, which was solved numerically. Quantum yields and decay lifetimes were obtained from these results and compared to the experimental data. The role of the ligand‐to‐metal charge transfer (LMCT) states was ascertained. A theoretical ligand field and intensity analysis was carried out and the results agree very well with the emission spectra. The molecular structures of the lanthanide cryptates were successfully modelled by the Y^III^ ion using the restricted Hartree–Fock (RHF) method, with the advantage of dealing with closed‐shell systems. These molecular structures were used to explain the drastic differences in the photophysics of the three Eu^III^ cryptates.