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Conferences by Professor Makoto Fujita

The Madeira Chemistry Research Center (CQM) will organize two conferences in the scope of Professor Makoto Fujita (University of Tokyo) visit to the University of Madeira, from 1st to 2nd June 2017.

The first conference will focous on the "Mathematical Control in the Chemical Construction of Archimedean/non-Archimedean Solids" and will take place in 1st of June 2017. On the second day of his visit Professor Makoto Fujita will offer a new lesson about "Crystalline Sponge Method for Synthetic and Natural Product Studies".

Both conferences willl be held at the University of Madeira, Amphitheater 10, 10h00.

Registration

Participants must make their registration here, until 30th May 2017.

 

Abstracts

"Mathematical Control in the Chemical Construction of Archimedean/non-Archimedean Solids"

Makoto Fujita, Department of Applied Chemistry, The University of Tokyo.

Breakthroughs are always somewhat beyond anything that humans can logically predict. This story was also triggered by an unexpected compound that we stumbled upon by chance. We have been studying the chemical construction of various "molecular polyhedra" that are self-assembled from metal ions (M, typically palladium ions) and rigid bent organic molecules (L, abbreviating “ligand” that bridges metal ions).1,2) Metals and ligands are mapped as nodes and edges of polyhedra. This approach (metal-ligand self-assembly) has provided highly efficient and powerful methods to construct discrete giant molecular structures, and several groups have been intensively studying the self-assembly of coordination polyhedra whose framework topologies are described by Platonic or Archimedian solids. The largest structure we have synthesized is M30L60 icosidodecahedron, one of the Archimedian solids.3) During further attempts to obtain larger frameworks, we unexpectedly obtained another M30L60 entity consisting of a simple combination of eight triangles and 24 squares, a polyhedron that is NOT depicted in any general textbook of elementary geometry. Puzzled by this observation, we attempted to mathematically rationalize this unexpected polyhedron, and here demonstrate a new series of self-assembled polyhedra based on a theory seldom discussed: the extended Goldberg polyhedra. The common Goldberg polyhedral are made up of hexagons and pentagons with three edges meeting at every node of the polyhedron; well-known real-life examples include footballs and fullerenes. Here, we simply extend this “trivalent” form to generate a new family of “tetravalent” Goldberg polyhedra, made up of squares and triangles.4) These extended tetravalent Goldberg polyhedra are not described in the literature, presumably because nothing like them has ever been discovered in the real world. However, the square planar geometry of palladium(II) ions has the potential to direct the self-assembly of these unnatural polyhedra, allowing us to synthesize them in the laboratory. We further demonstrate the self-assembly of M48L96, an extended Goldberg polyhedron, which was predicted by the theory. The embodiment of the tetravalent Goldberg polyhedra will have a knock-on effect in other fields, and may lead to, for example, the discovery of new virus capsids with this specific topology.

Figure. X-ray crystal structure of the self-assembled M30L60 complex (d = 8.2 nm).

References

1) M. Tominaga, K. Suzuki, M. Kawano, T. Kusukawa, T. Ozeki, S. Sakamoto, K. Yamaguchi, and M. Fujita, Angew. Chem. Int. Ed. 2004, 43, 5621-5625. (2) Q.-F. Sun, J. Iwasa, D. Ogawa, Y. Ishido, S. Sato, T. Ozeki, Y. Sei, K. Yamaguchi, and M. Fujita, Science 2010, 328, 1144-1147. (3) D. Fujita, Y. Ueda, S. Sato, H. Yokoyama, N. Mizuno, T. Kumasaka, M. Fujita, Chem 2016, 1, 91-101.  (4) D. Fujita, Y. Ueda, S. Sato, N. Mizuno, T. Kumasaka, M. Fujita, Nature 2016, 540, 563–566

 

 

"Crystalline Sponge Method for Synthetic and Natural Product Studies"

Makoto Fujita, Department of Applied Chemistry, The University of Tokyo.

X-ray single crystal diffraction (SCD) analysis has the intrinsic limitation that the target molecules must be obtained as single crystals. Here, we report a new protocol for SCD analysis that does not require the crystallization of the sample.1-5 In our method, tiny crystals of porous complexes are soaked in the solution of a target, where the complexes can absorb and orient the target molecules in the pores. 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. With chiral guests, the space group of the crystal turned into chiral, enabling the determination of absolute configuration of the guests by anomalous scattering effect from the host heavy atoms (Zn and I). In this talk, following a general discusson,6-11 the applications of the method for natural product chemistry, synthetic chemistry, and pharmaceutical research will be discussed. The absolute configurations of elatenyne, first isolated in 1986, has still not been unequivocally confirmed because of its almost achiral meso-formed core structure that results in nearly zero []D specific rotation. This faint chirality, defined only by the slight difference in the two alkyl side-chains, was precisely discriminated by the crystalline sponge and its absolute structure was reliably determined. 12 The total amount required for the experiments was only ~100 µg and the majority of this (95 µg) could be recovered after the experiments.

 

References

1) K. Biradha and M. Fujita, Angew. Chem. Int. Ed. 2002, 41, 3392-3395.

2) O. Ohmori, M. Kawano, and M. Fujita, J. Am. Chem. Soc. 2004, 126, 16292-16295.

3) Y. Inokuma, S. Yoshioka, J. Ariyoshi, T. Arai, Y. Hitora, K. Takada, S. Matsunaga, K. Rissanen, M. Fujita 
Nature 2013, 495, 461-466; Corrigendum: Nature 2013, 501, 262

4) Y. Inokuma, S. Yoshioka, J. Ariyoshi, T. Arai, M. Fujita 
Nat. Protoc. 2014, 9, 246-252.

5) K. Ikemoto , Y. Inokuma , K. Rissanen , and M. Fujita 
J. Am. Chem. Soc. 2014, 136, in press.

6) T. R. Ramadhar, S.-L. Zheng, Y.-S. Chen and J. Clardy, Acta Cryst., 2015, A71, 46–58

7) S. Yoshioka, Y. Inokuma, M. Hoshino, T. Sato, M. Fujita Chem. Sci. 2015, 6, 3765-3768.

8) N. Zigon, M. Hoshino, S. Yoshioka, Y. Inokuma, and M. Fujita, Angew. Chem., IE, 2015, 54,

9) A. B. Cuenca, N. Zigon, V. Duplan, M. Hoshino, M. Fujita, and E. Fernández, Chem. Euro J. 2016, 4723-4726 [DOI: 10.1002/chem.201600392]

10) M. Hoshino, A. Khutia, H. Xing, Y. Inokuma, M. Fujita, IUCrJ, 2016, 3, 139-151.

11) V. Duplan, M. Hoshino, W. Li, T. Honda, and M. Fujita, Angew. Chem. Int. Ed. 2016, 55, 4919-4923 [DOI: 10.1002/anie.201509801R1]

12) S. Urban, R. Brkljac, M. Hoshino, S. Lee, and M. Fujita, Angew. Chem. Int. Ed. 2016, 55, 2678-2682. [DOI: 10.1002/anie.201509761]

 
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