title: Adsorption-induced conformational isomerization of alkyl-substituted thiophene oligomers on Au(111): impact on the interfacial electronic structure.
abstract: Alkyl-substituted quaterthiophenes on Au(111) form dimers linked by their alkyl substituents and, instead of adopting the trans conformation found in bulk oligothiophene crystals, assume cis conformations. Surprisingly, the impact of the conformation is not decisive in determining the lowest unoccupied molecular orbital energy. Scanning tunneling microscopy and spectroscopy of the adsorption geometries and electronic structures of alkyl-substituted quaterthiophenes show that the orbital energies vary substantially because of local variations in the Au(111) surface reactivity. These results demonstrate that interfacial oligothiophene conformations and electronic structures may differ substantially from those expected based on the band structures of bulk oligothiophene crystals.
authors.affiliation: †Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, United States.
authors.forename: Benjamen N
authors.initials: BN
authors.lastname: Taber
authors.affiliation: †Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, United States.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Kislitsyn
authors.affiliation: †Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, United States.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Gervasi
authors.affiliation: ‡Center for Advancing Electronics Dresden, Dresden University of Technology, 01062 Dresden, Germany.
authors.forename: Stefan C B
authors.initials: SC
authors.lastname: Mannsfeld
authors.affiliation: §Silvio O. Conte National Center for Polymer Research, Department of Polymer Science and Engineering, University of Massachusetts-Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: §Silvio O. Conte National Center for Polymer Research, Department of Polymer Science and Engineering, University of Massachusetts-Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States.
authors.forename: Alejandro L
authors.initials: AL
authors.lastname: Briseno
authors.affiliation: †Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403, United States.
authors.forename: George V
authors.initials: GV
authors.lastname: Nazin
keywords: adsorption configuration; oligothiophene; organic electronics; quaterthiophene; scanning tunneling spectroscopy; surface reconstruction