Characterizing the Solution Properties of Supramolecular Systems by Analytical Ultracentrifugation

Schubert, Dieter; Tziatzios, Christos; Schuck, Peter; Schubert, Ulrich S.

Abstract:

Analytical ultracentrifugation is the study of the movement or the local distribution of dissolved supraor macromolecular particles under the influence of centrifugal force, by measuring and evaluating concentration- versus-radius distributions in the sample. This paper describes application of the method to the determination of the state of association of supramolecular compounds in solution. Both principles and experimental techniques are considered and applied to a special metal coordination array. Those methods analyzing the ªtransient º sedimentation patterns, namely, sedimentation velocity experiments and the ªapproach to equilibriumº, can yield information on aggregate size within less than approximately 3 h. In particular, by the approach to equilibrium method (Archibald method) the average molar mass of the dissolved compound can be determined within about 30 min. Sedimentation equilibrium analysis can yield the percentage of the different aggregates present and, for reversibly associating systems, association constants.

Year:

1999

Type of Publication:

Article

Keywords:

analytical methods; analytical ultracentrifugation; association in solution; supramolecular chemistry

Journal:

Chemistry - A European Journal

Volume:

5

Pages:

1377 – 1383