Abstract

The coordination chemistry and the volumetric properties of three representative lanthanoid(III) ions-lanthanum(III), gadolinium(III), and lutetium(III)-have been studied in three amide solvents with gradually increasing spatial demand upon coordination: N,N-dimethylformamide (dmf) < N,N-dimethylacetamide (dma) < N,N-dimethylpropionamide (dmp). Large angle X-ray scattering (LAXS) and EXAFS have been used to determine the structure of the solvated lanthanoid(III) ions in solution, further supplemented with a crystallographic study on octakis(N,N-dimethylacetamide) lanthanum(III) triflate, [La(dma)8](CF3SO3)3. The selection of ions and solvents allows an estimate of the steric congestion effects on the resulting coordination number, CN, ranging from nine for lanthanum(III) ions in dmf to seven for the smaller lutetium(III) ion in space-demanding dma. The standard partial molar volumes of the solvated lanthanoid(III) ions in water and dmf are reflected in the CNs, as these solvent molecules are small enough to not interfere with each other upon coordination. However, the larger and more space-demanding dma displays a different pattern with an almost constant standard partial molar volume and a decreasing CN, counterbalancing the difference in ionic radius of the lanthanoid(III) ion.

Keywords

APPARENT MOLAR VOLUMES; NUCLEAR-MAGNETIC-RESONANCE; X-RAY-SCATTERING; HEAT-CAPACITIES; DIMETHYLFORMAMIDE EXCHANGE; RAMAN-SPECTROSCOPY; CRYSTAL-STRUCTURE; SOLVENT MIXTURES; AQUEOUS-SOLUTION; N,N-DIMETHYLFORMAMIDE

Published in

Journal of Physical Chemistry B
2013, Volume: 117, number: 28, pages: 8502-8511

SLU Authors

• Persson, Ingmar

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Lundberg, Daniel

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Physical Chemistry


Publication identifier

DOI: https://doi.org/10.1021/jp310111j

Permanent link to this page (URI)

https://res.slu.se/id/publ/44430