"Fascinated by metals
and self-assembly"

Makoto FUJITA, Tokyo

Vendredi 24 avril
10h30
Amphi 2
Institut le Bel

Abstract :
Molecular self-assembly based on coordination chemistry has made an explosive development in recent years. Over the last quarter century, we have been showing that the simple combination of transition-metal’s square planer geometry (a 90 degree coordination angle) with pyridine-based bridging ligands gives rise to the quantitative self-assembly of discrete (and infinite) coordination frameworks. Representative examples include square molecules (1990), linked-ring molecules (1994), cages (1995), tubes (2004), and capsules (1999) that are self-assembled from simple and small components. Within the hollow of these structures, the cavity-directed reaction and property control of organic molecules have been developed, which represent one of the most important features of three-dimentional hosts. Furthermore, the principle and the power of coordination self-assembly has been applied to the bottom-up construction of discrete, well-defined nano-scale structures. Large (>100) multi-component systems offer not only structural but also mechanistic insights into even biological assembly. In the lecture, a new method for X-ray single crystal diffraction (SCD) analysis of small molecules will be also discussed that does not require the crystallization of the sample. In our method, tiny crystals of porous complexes self-assembled from metals and ligands are soaked in the solution of a target, where the complexes can absorb the target molecules. The crystallographic analysis clearly determines the absorbed guest structures along with the host frameworks. As the SCD analysis is carried out with only one tiny crystal, the required sample amount is of the nano-to-microgram order. In summary, through these studies, we have been fascinated for all our chemistry life by metals and self-assembly.