Stephen J. Loeb
	Inorganic and Supramolecular Chemistry
	Ph.D. (Western Ontario)
	loeb@uwindsor.ca
	University Professor Canada Research Chair
	253-3000 Ext. 3529
	375-2 Essex Hall
	Personal Homepage

Supramolecular Chemistry: Self-Assembly, Molecules and Materials

Self-assembly techniques can be applied to the synthesis of nanoscale molecules employing multiple non-covalent forces such as hydrogen bonding, π-stacking, metal-ligand coordination or a combination of interactions. The advantage of this approach is that molecular components can be organised in high yield under thermodynamic control. Our research group has a number of different projects in the traditional areas of synthetic organic chemistry, physical organic chemistry, coordination chemistry and organometallic chemistry. The unifying theme is supramolecular chemistry and the control of molecular function whether it is in solution, in the solid-state or on a surface.

Some examples are outlined below - for details see the Loeb Group Web Page

Metal-Organic Rotaxane Frameworks (MORFs)

Mechanically interlocked molecules such as rotaxanes and catenanes have shown to be particularly useful for the construction of molecular machines. Although a great deal of information about the dynamic nature and fundamental switching properties of these systems has been derived from solution studies, there is a need for strategies which could lead to the fabrication of solid state nanoscale devices from these molecules. A number of methodologies for imposing higher order on individual rotaxanes have been investigated. We are assembling them into the repeating framework of a crystalline lattice; the formation of metal-based polyrotaxanes which we term metal-organic rotaxane frameworks (MORFs).

• S. J. Loeb, Chem. Commun. 2005, 1511. – Invited Feature Article, Front Cover
• D. J. Hoffart, S. J. Loeb, Angew. Chem. Int. Ed. Engl. 2005, 44, 901.
• G. J. E. Davidson, S. J. Loeb, Angew. Chem. Int. Ed. Eng., 2003, 42, 77. – Featured in frontispiece

Synthetic receptors for anions frequently incorporate a combination of i) hydrogen bond donor groups, ii) a positively charged component for effective electrostatic interactions and iii) a suitable framework onto which these structural components can be assembled. We have employed a new design: metal-organic anion receptor containing amide, pyrrole or urea functionalized ligands that exhibit remarkably strong and selective binding for various targeted anions.

• I. El Drubi Vega, P. A. Gale, M. E. Light, S. J. Loeb, Chem. Commun. 2005, 4913.
• C. R. Bondy, P. A. Gale, S. J. Loeb, J. Am. Chem. Soc. 2004, 5030. - Highlighted in Science.
• C. R. Bondy, P. A. Gale, S. J. Loeb, Chem. Commun. 2001, 729.

Hydrogen Bonded Networks Via Second-sphere Coordination

The drive to produce new technologically relevant materials and understand the intricate details of how molecules assemble into such materials (crystal engineering) has resulted in extensive research into the nature of hydrogen bonded networks. A synthetic strategy that has received little attention is the systematic application of second-sphere coordination to build such hydrogen bonded systems. This should be of particular interest as a methodology for incorporating and positioning metal sites and therefore potential sources of magnetic and electronic phenomena.

• D. A. Beauchamp, S. J. Loeb, Chem. Eur. J. 2002, 8, 5084-5088. - Featured on Front Cover