title: Pentagonal tiling with buckybowls: pentamethylcorannulene on Cu(111).
abstract: We present scanning tunnelling microscopy studies and first principles calculation on the 2D crystallization of pentagonal pentamethylcorannulene on a Cu(111) surface under ultrahigh vacuum in the temperature range of 50 K to 400 K. The observed 2D crystal phases and their packing densities are compared to tiling options of hard pentagons. Temperature change-induced reversible phase transitions reveal entropic effects in 2D crystallization. Only inclusion of dispersion interactions into density functional theory yields structures observed experimentally at low temperatures.
authors.affiliation: Organic Chemistry Institute, University Zurich, CH-8057 Zürich, Switzerland.
authors.forename: Laura
authors.initials: L
authors.lastname: Zoppi
authors.forename: Tobias
authors.initials: T
authors.lastname: Bauert
authors.forename: Jay S
authors.initials: JS
authors.lastname: Siegel
authors.forename: Kim K
authors.initials: KK
authors.lastname: Baldridge
authors.forename: K-H
authors.initials: KH
authors.lastname: Ernst