ISMSC 2007 - Università degli Studi di Pavia

Amplification of a Molecular Solomon Knot
PSB 39
Cari D.Pentecost, Nicholas Tangchaivang, Kelly S. Chichak, Andrea J. Peters, Stuart J. Cantrill
and J. Fraser Stoddart
California NanoSystems Institute and Department of Chemistry and Biochemistry, University of
California Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095, USA
(cari@chem.ucla.edu)
The four-noded, two-component link known as the Solomon Knot (SK) has been said to contain
all of the wisdom of King Solomon. For several centuries, many cultures have adopted this
emblem to represent knowledge. SKs can be found in many different settings from adorning the
crowns of African kings to being incorporated into the architecture of university libraries. With
the advent of new synthetic methodologies that are advancing under the umbrella of templatedirected
synthesis, chemists are beginning more and more to appreciate the subtleties of
topologically interesting structures, and have consequently pursued the synthesis of their
molecular analogues. For example, the complete molecular construction of the Borromean ring
(BR) topology and its derivatives has been achieved successfully from 18 individual
components under strict dynamic covalent, coordinative and supramolecular control. In a
similar fashion, we have recently obtained the SK molecular topology from 12 individual
components, resulting from mixing Cu(II) and Zn(II) metal templates in a 1:1 ratio, leading to the
formation of the SKs in preference to the BRs. This finding suggests that, in these dynamic
mechanically interlocked systems, there is present, under the appropriate conditions, a dynamic
combinatorial library, from which it is possible, during a crystallization process that is kinetically
controlled, to amplify (Box) one of the members of the library.
[1] (a) Chichak, K. S.; Cantrill, S. J.; Pease, A. R.; Chiu, S.-H.; Cave, G. W. V.; Atwood, J. L.;
Stoddart, J. F. Science 2004, 304, 1308–1312. (b) Cantrill, S. J.; Chichak, K. S.; Peters,
A. J.; Stoddart, J. F. Acc. Chem. Res. 2005, 38, 1–9..
[2] Pentecost, C.D.; Peters, A. J.; Chichak, K. S.; Cave, G. W. V.; Cantrill, S.J.; Stoddart, J.
F. Angew. Chem. 2006, 45, 4099–4104.
[3] Pentecost, C.D.; Chichak, K. S.; Peters, A. J.; Cave, G. W. V.; Cantrill, S.J.; Stoddart, J.
F. Angew. Chem. 2007, 46, 218–222
Self-Assembled Resorcinarene Monolayers on Gold
Jade Pettersen a , Mauro Mocerino a , Mark Ogden a , Andrew Ross b , Peter Eadington b
a Nanochemistry Research Institute, Curtin University of Technology, Perth, Australia.
b CSIRO Petroleum, Australian Resources Research Centre, Perth, Australia.
PSB 40
Self Assembled Monolayers (SAM's) are highly ordered structures formed by the spontaneous
adsorption of a compound onto a suitable substrate. A variety of sulfur species are known to
adsorb onto gold, for example physisorbed monolayers are formed in the presence of dialkyl
sulfides, while chemisorbed monolayers are formed from disulfides, thiols and thioacetates. 1
Monolayers of simple sulfur functionalised resorcinarenes have been reported by a variety of
groups and have been used for applications as diverse as coating gold nanoparticles 2 to
selective sensing devices 3 . Resorcinarenes are typically used as receptors, and are capable of
complexing with a wide range of guest molecules. 4 Their bowl-like shape and eight hydroxyl
groups on the upper rim make them an ideal scaffold on which to build more complex
structures.
Our goal is to prepare surfaces composed of various fuctionalised resorcinarenes for
applications in sensing. The work presented will include the synthesis of a variety of
resorcinarenes as well as recent work involving their use in the formation of self-assembled
monolayers.
[1] J. Love, L. Estroff, J. Kriebel, R. Nuzzo, G. Whitesides, Chem. Rev., 2005, 105,1103-1169.
[2] B. Kim, R. Balasubramanian, W. Perez-Segarra, A. Wei, B. Decker and J. Mattay, Supramol.
Chem., 2005, 17,173-180.
[3] J. Faull, and V. Gupta, Thin Solid Films, 2003, 440, 129-137.
[4] P. Timmerman, W. Verboom, and D. Reinhoudt, Tetrahedron,1996, 52, 2663-2704.