Henry Rzepa, Talks And Presentations

Both chirality and aromaticity are cornerstone concepts for organic chemistry. Both had their origins in the 1840s or thereafter in the work of Pasteur, van't Hoff and LeBel for the former and Faraday, Loschmidt, Kekule, Armstrong for the latter, this reaching its first stage of theoretical maturity with Huckel's quantum mechanical analysis in the 20th Century (the famous 4n+2 rule). For a long period, these two concepts were thought to be exclusive; after all aromaticity manifested almost entirely in flat (achiral) benzenoid rings! Another concept, topology, also originated in the 1840s, having been coined by the mathematician Johann Listing, who also proposed fascinating topological objects such as trefoil knots, and rings now better known by their co-discoverer, Mobius. In the 1960s, the concepts of Mobius topologies and aromaticity started merging. The chemist Heilbronner proposed aromaticity rules for Mobius cycles, although he did not identify such cycles as being chiral (this property appears to have