ISMSC 2007 - Università degli Studi di Pavia

40 years of polyazamacrocycles. A personal historical view.
Thomas A. Kaden
Department of Chemistry, University of Basel, Spitalstrasse 52, CH 4056 Basel, Switzerland.
PL 1
A review of the chemistry of polyazamacrocycles [1] will show how the syntheses of such
compounds have been improved, how the size of the macrocyclic ring plays an important role in
the complexation process (macrocyclic effect), how the geometry of the metal ion complexes
can be controlled, how spectral and magnetic properties as well as the electrochemistry and
kinetics of complex formation and dissociation are dependent on the properties of these ligands.
Further developments in this field of chemistry have been the functionalisation of the
macrocycles with groups, which can be used to modify their solubility and thus their extraction
properties, or their coordination properties, or can form covalent bonds so that macrocyclic
complexes can be attached to other molecules, or can carry reactive groups so that one can
study metal promoted reactions.
The synthesis of homo- and heteroditopic bis-macrocycles allows to prepare new compounds,
which depending on the distance between the two metal centres show interesting chemical and
physical properties. In addition homo- and heteropolytopic systems based on more than two
macrocycles and open chain ligands have also been prepared and their metal complexes
studied in detail.
Finally a review of applications will be given: on one side molecular machines based on
polyazamacrocycles and on the other side the use of such macrocycles and their metal
complexes in medicine.
[1] For reviews on polyazamacrocycles see:
- N.F. Curtis, Coord. Chem. Rev., 1968, 3, 3;
- Th. A. Kaden, Topics Curr. Chem., 1984, 121, 157;
- P. Bernhardt, P. Lawrance, Coord. Chem. Rev., 1990, 104, 297;
- Th. A. Kaden, Advances Supramol. Chem., 1993, 3, 65;
- M. Meyer, V. Dahaoni-Gindrey, C. Lecomte, R. Guilard, Coord. Chem. Rev., 1998, 178-180,
1313.
Shape-controlled functional materials created by modification of
preorganized assemblies
Seiji Shinkai
Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu
University, 744 Motooka, Nishi-ku, Fukuoka, 819-0391, Japan
PL 2
Combination of supramolecular chemistry with molecular recognition has been successfully
applied to creating large superstructures with a wide variety of morphologies. Control of shapes
and patterns of ordered molecular assemblies in nano and micro scales has attracted
considerable interest as promising bottom-up technology. It is known, however, that these
molecular assembling superstructures are fragile, reflecting the characteristic of the noncovalent
interaction, a driving force operating in these molecular systems. In fact, they easily
collapse or change by small perturbation in the environmental conditions. Thus, over the last
decade, researchers have been seeking possible methods for the immobilization of these
superstructures. This lecture focuses on recent advances in molecular orientation facilitated by
guest inclusion, in situ post-modification under the influence of the molecular assemblies as
templates, and post-polymerization of ordered molecular assemblies such as organogel fibers
and crystals to preserve their original superstructures and intensify their mechanical
strength.[1,2]
[1] For a recent review, see K. Sada, M. Takeuchi, N. Fujita, M. Numata and S. Shinkai, Chem.
Soc. Rev., 2007, 36, 415-435
[2] I. Hwang et al., Angew. Chem. Int. Ed., 2007, 46, 210-213; P. Mukhopadhyay et al., ibid.,
2006, 45, 1592-1595; T. Kishida et al., Org. Biomol. Chem., 2006, 4, 1902-1909