Nino Bašić: The curious case of the Coulson conjecture on maximum bond number

Povzetek: We will revisit a longstanding claim about maximum π bonding in Hückel systems. The maximum sum of Coulson bond orders (i.e., the maximum π bond number) for a carbon centre of an sp² π system is widely stated to be √3. This belief is apparently factually correct, but has not been formally proved. We provide empirical evidence on the behaviour of maximum π bond number as a function of vertex count, n, of chemical graphs and describe the family of graphs that realises local maxima for small n.

This is joint work with Patrick W. Fowler.