Coordination Reactions of 5-(2-(4-Bromophenyl)ethynyl)pyrimidine in On-Surface Synthesis

The coordination reactions of 5-(2-(4-bromophenyl)ethynyl)pyrimidine (PEPmBr) molecules on Ag(111) was studied by low-temperature scanning tunneling microscopy (LT-STM). First, vapor deposition of PEPmBr molecules onto Ag(111) at room temperature leads to the formation of a large-scale pinwheel-like self-assembly structure. Then hierarchical coordination reactions were employed to synthesize organometallic dimers and tetramers on Ag(111) surface. In contrast to the releasing of the coordinated Ag atoms and forming covalent bonds, it is found herein that further thermal activation induces the rotation of the C-Ag-C and N-Ag-N coordination bonds, resulting in various organometallic nanoteris with triangle, rectangle, and zigzag structures.