title: Colloidal nanocube supercrystals stabilized by multipolar Coulombic coupling.
abstract: We explore microscopic principles governing the self-assembly of colloidal octylamine-coated platinum nanocubes solvated in toluene. Our experiments show that regular nanocubes with an edge length of l(RC) = 5.5 nm form supercrystals with simple cubic packing, while slightly truncated nanocubes with an edge length of l(TC) = 4.7 nm tend to arrange in fcc packing. We model by averaged force fields and atomistic molecular dynamics simulations the coupling forces between these nanocrystals. Our detailed analysis shows that the fcc packing, which for cubes has a lower density than simple cubic packing, is favored by the truncated nanocubes due to their Coulombic coupling by multipolar electrostatic fields, formed during charge transfer between the octylamine ligands and the Pt cores.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Henry
authors.initials: H
authors.lastname: Chan
authors.forename: Arnaud
authors.initials: A
authors.lastname: Demortière
authors.forename: Lela
authors.initials: L
authors.lastname: Vukovic
authors.forename: Petr
authors.initials: P
authors.lastname: Král
authors.forename: Christophe
authors.initials: C
authors.lastname: Petit