2D Assembly of Metallacycles on HOPG by Shape-Persistent Macrocycle Templates

The synthesis and scanning tunneling microscopy (STM) investigations of shape-persistent arylene-ethynylene-butadiynylene macrocycles along with their codeposites with metallacycles are reported. 2D ordered arrays of macrocycles and macrocycle/metallacycle architectures (1:1) have been obtained on HOPG by self-assembly under ambient conditions. It is found that the ordered macrocycle array acts as a template for the deposition of the adlayer molecules. For each underlying macrocycle, one metallacycle has been detected. The unit-cell data of both, the macrocycles; and their codeposites, show that the structural information of the macrocycle layer is perfectly transformed to the guest molecules. A rather unexpected observation is that the present compound could not be coadsorbed with C-60, indicating that only a minor change in the structure of the macrocycle has a dramatic effect on the ability of the monolayer to bind additional guest molecules.