title: C60-pentacene network formation by 2-D co-crystallization.
abstract: We report experiments highlighting the mechanistic role of mobile pentacene precursors in the formation of a network C(60)-pentacene co-crystalline structure on Ag(111). This co-crystalline arrangement was first observed by low temperature scanning tunneling microscopy (STM) by Zhang et al. (Zhang, H. L.; Chen, W.; Huang, H.; Chen, L.; Wee, A. T. S. J. Am. Chem. Soc. 2008, 130, 2720-2721). We now show that this structure forms readily at room temperature from a two-dimensional (2-D) mixture. Pentacene, evaporated onto Ag(111) to coverages of 0.4-1.0 ML, produces a two-dimensional (2-D) gas. Subsequently deposited C(60) molecules combine with the pentacene 2-D gas to generate a network structure, consisting of chains of close-packed C(60) molecules, spaced by individual C(60) linkers and 1 nm x 2.5 nm pores containing individual pentacene molecules. Spontaneous formation of this stoichiometric (C(60))(4)-pentacene network from a range of excess pentacene surface coverage (0.4 to 1.0 ML) indicates a self-limiting assembly process. We refine the structure model for this phase and discuss the generality of this co-crystallization mechanism.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Jin
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Dougherty
authors.forename: William G
authors.initials: WG
authors.lastname: Cullen
authors.forename: Steven
authors.initials: S
authors.lastname: Robey
authors.forename: Janice E
authors.initials: JE
authors.lastname: Reutt-Robey
mesh_terms: D000327:Adsorption; D003460:Crystallization; D004058:Diffusion; D037741:Fullerenes / Q000737:chemistry*; D005740:Gases; D008853:Microscopy / Q000379:methods; D016252:Microscopy, Scanning Tunneling / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010316:Particle Size; D012834:Silver / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
chemical_list: D037741:Fullerenes; D005740:Gases; D012834:Silver; C069837:fullerene C60