Polyaromatic hydrocarbons have been studied extensively because of their electronic properties which make them ideal candidates for applications in organic electronics and photovoltaics. Borazine is isoelectronic with benzene but, being insulating, represents its natural counterpart in self-assembled nanoscale functional materials.
Novel borazine compounds were synthesised by the Bonifazi group from the University of Namur in Belgium and were deposited onto a Cu(111) substrate for analysis by scanning tunnelling microscopy by Nataliya Kalashnyk and Ben Moreton of the Costantini group. Comparison of the borazine compounds showed a distinct difference between their assemblies which was explained with the aid of Kinetic Monte Carlo simulations performed by the de Vita group of King’s College London.
Hexaaryl borazine forms near perfect monolayers on Cu(111) whereas introducing a reactive OH substituent in hydroxypentaaryl borazine generates “magic” clusters. The origin of this difference is based upon the ability of the Cu(111) substrate to deprotonate the OH groups, generating a charged species and allowing for an interplay between short range van der Waals attraction and long range Coulombic repulsion.
For more information see Angewandte Chemie International Edition.