The 592^nd meeting of the Sydney University Chemical Society will be held on Monday 14^th July in Le Fèvre Lecture Theatre 2 of the Chemistry Building on the campus of The University of Sydney. The speaker will be Prof. J. Fraser Stoddart from the University of California at Los Angeles, who will deliver the 2003 Liversidge Lecture.

While covalent synthesis has dominated the development of organic chemistry for well over a century now, chemical synthesis does not begin and end with the making and breaking of covalent bonds, particularly if – but not only if – one looks beyond the chemistry of carbon compounds. In the wake of coordination chemistry and with the advent of supramolecular (host-guest) chemistry, noncovalent synthesis, whether it be under the guise of strict self-assembly or part of supramolecular assistance to covalent synthesis, now occupies a central role in the production of complexes and compounds of all sizes and shapes. Template-directed synthesis, involving coordinative as well as noncovalent and covalent bond formation, aids and abets the efficient production of compounds that would otherwise be difficult to produce. If the template is consumed stoichiometrically in the process, then a wide range of interlocked molecular compounds can ensue. Furthermore, the weak interactions used to make these compounds live on inside them afterwards. The result is motor-molecules that can be driven in a mechanical sense by chemicals, electrons or photons. Then, there is the option to conduct template-directed synthesis under thermodynamic as well as kinetic control. When thermodynamics rule okay, virtual combinatorial libraries can be formed, allowing substrates to be cast and receptors to be molded. Dynamic covalent synthesis enjoys the adaptability of supramolecular systems and the robustness we generally associate with the covalent bond. All this progress is encouraging and we have certainly come a long way in a short period of time. But there is a major shortcoming of most synthetic chemistry, i.e., it leads to products which we tend to study in the solution phase, or in the crystalline state, or failing those, in either the gaseous or liquid phases – not forgetting the liquid crystalline one. One of the major challenges today is to do chemical synthesis in the context of the condensed phase of matter with the prospect of producing, amid the relative coherence that characterizes Langmuir-Blodgett films and self-assembled monolayers on suitable substrates, for example, a device or gadget that might find application in the fullness of time.

The lecture will present arguments for giving chemical synthesis a wide berth these days. It will challenge synthetic chemists to practice synthesis from a broad palette and perspective. It will highlight how the emergence of the mechanical bond in chemistry during the last two decades has brought with it a real prospect of integrating a bottom-up approach based on self-assembly and self-organization of motor-molecules with a top-down approach based on micro- and nanofabrication to (i) construct molecular electronic devices to store and process information at very high densities using minimal power and (ii) to create NanoElectroMechanical Systems (NEMS) in order to harness, manipulate, and transfer energy on the nanoscale level. It is an integrated systems-oriented approach to nanotechnology that finds its inspiration in the transfer of concepts like molecular recognition from the life sciences into materials science.