DIFFERENTIATION OF CHEMICALLY FUNCTIONAL-GROUPS IN STEAROYL AMIDE ANDANILIDE WITH SCANNING-TUNNELING-MICROSCOPY

Scanning tunneling microscopy (STM) was applied to distinguish chemica lly functional groups in stearoyl amide and anilide molecules adsorbed on the liquid-solid interface of phenyloctane and graphite. In contra st to previously reported carboxyl and hydroxyl groups, amide and anil ide groups were imaged as more readily tunneling parts than the hydroc arbon part. Stearoyl amide molecules were in a head-to-head alignment suggesting hydrogen bonding between the amide groups, while stearoyl a nilide molecules were in a head-to-tail arrangement. The STM images we re compared with the shape of the molecular orbitals calculated for is olated molecules to confirm the intuitive assignment of the functional groups.