In situ STM imaging of Au(100) electrode in 1 M HClO4 + 0.03 M aniline revealed highly ordered aniline adlattices of (2 radical 2 x 4 radical 2)R45 degrees and (radical 10 x radical 10)R18 degrees and polyaniline molecules exhibiting wiggling conformations at potentials negative and positive of 0.95 V (vs. reversible hydrogen electrode), respectively.