Local structure of the aminobenzoate isomers on Cu(110)

The growth and assembly of aminobenzoate (NH₂C₆H ₄COO^-) isomers (ortho, meta and para) on Cu(110) have been investigated with a scanning tunneling microscope (STM) at 4.7 K. At the initial stage, well-ordered islands of (4 × 3) and (3 × 4) superstructures are formed for ortho- and para-ammobenzoate layers, respectively. The growth of ortho- and para-aminobenzoate layers were found to proceed in different manner from each other, which is responsible for the intermolecular interaction through the hydrogen bunding. In the case of meto-aminobenzoate, short-ranged (6 × 4) superstructures were observed. Our STM study clearly demonstrates that the substituent position on the aminobenzoate affects not only the superstructure patterns but also their growth process. We suggest that the hydrogen bonding plays a key role in the molecular linkage, being controlled by positioning of the substituents.