Comparison of different methods for structural analysis of lanthanide-induced N...

• Author(s): Geraldes, Carlos F. G. C. ; Zhang, Shanrong ; Platas, C. ; Rodrí­guez-Blas, T. ; Blas, A. de ; Sherry, A. D.
• Date: 2001
• Persistent ID: http://hdl.handle.net/10316/3885
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Paramagnetic effects; Lanthanide-induced shifts; Solution structures; Cryptate
• Document Type: Article
• Language: English

Description

The three main methods available in the literature for lanthanide-induced shift (LIS) structural analysis of a series of lanthanide(III) complexes in solution are applied to the data available for a complete series of paramagnetic lanthanide cryptate complexes of a Schiff base axial macrobicyclic ligand L, [LnL]3+. The macrobicycle contracts its cavity as a result of the lanthanide contraction, while preserving the same overall structure in solution. This causes breaks in the LIS plots for all the three methods used. A combined analysis of the data allows to conclude that those breaks reflect abrupt changes of the crystal field parameter A20<r2> and the hyperfine constants Fi of the lanthanides in the middle of the series, but not of the structure of the complex in solution. http://www.sciencedirect.com/science/article/B6TWY-43BXWKG-8F/1/4616e022583602507b74136161dfff32