Cyanuric acid and metamine on Au(111): Structure and energetics of hydrogen-bonded networks

The adsorption and coadsorption of cyanuric acid (CA) and melamine (M) molecules on a Au(111) surface using scanning tunneling microscopy (STM), and the energetics of the homo-and heteromolecular interactions of M and CA, were analyzed. novel stoichiometric phase (CA1M3) was also identified, which formed upon sequential deposition of M followed by CA. Both CA and M were deposited by thermal sublimation from molecular evaporators. Large well-ordered islands were observed in the adsorption structures formed upon deposition of CA or M individually on Au(111). The herring-bone reconstruction of Au(111) did not change upon molecular adsorption and did not affected the self-assembly patterns. The dimer formed from M molecules involved two hydrogen bonds between the NH donor and N acceptor groups, while the heterodimer formed through coupling on one M and one CA molecule involved one NH-N and two NH-O hydrogen bonds.