Potential and anion effects on the adsorption of 3′,4′-bis(hexylthio)-2,2′:5′,2′'-terthiophene on Au(1 1 1) electrode characterized by in situ STM

•In situ STM imaging DTDST molecule adsorbed on an ordered Au(111) electrode in sulfuric and perchloric acid.•Potential control transforms the disordered DTDST into a well - ordered adlayer.•Anion coadsorption affects spatial structure of DTDST at positive potential.•The internal molecular structure of DTDST molecule adsorbed on an Au(111) electrode is revealed by molecular resolution STM imaging.