Linked Life Data

17488115

Source:http://linkedlifedata.com/resource/pubmed/id/17488115

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2007-5-24
pubmed:abstractText
Adsorption structures formed from a class of planar organic molecules on the Au(111) surface under ultrahigh vacuum conditions have been characterized using scanning tunneling microscopy (STM). The molecules have different geometries, linear, bent, or three-spoke, but all consist of a conjugated aromatic backbone formed from three or four benzene rings connected by ethynylene spokes and functionalized at all ends with an aldehyde, a hydroxyl, and a bulky tert-butyl group. Upon adsorption, the molecules adopt different surface conformations some of which are chiral. For the majority of the observed adsorption structures, chirality is expressed also in the molecular tiling pattern, and the two levels of chirality display a high degree of correlation. The formation and chiral ordering of the self-assembled structures are shown to result from dynamic interchanges between a diffusing lattice gas and the nucleated islands, as well as from a chiral switching process in which molecules alter their conformation by an intramolecular rotation around a molecular spoke, enabling them to accommodate to the tiling pattern of the surrounding molecular structures. The kinetics of the conformational switching is investigated from time-resolved, variable temperature STM, showing the process to involve an activation energy of approximately 0.3 eV depending on the local molecular environment. The molecule-molecule interactions appear primarily to be of van der Waals character, despite the investigated compounds having functional moieties capable of forming intermolecular hydrogen bonds.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
111
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5850-60
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Chiral ordering and conformational dynamics for a class of oligo-phenylene-ethynylenes on Au(111).
pubmed:affiliation
Interdisciplinary Nanoscience Center, iNANO, University of Aarhus, Aarhus C, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't