Linked Life Data

20218660

Source:http://linkedlifedata.com/resource/pubmed/id/20218660

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2010-3-24
pubmed:abstractText
We report the electrical transport characteristics of conjugated oligonaphthalenefluoreneimine (ONI) wires having systematically varied lengths up to 10 nm. Using aryl imine addition chemistry, ONI wires were built from gold substrates by extending the conjugation length through imine linkages between highly conjugated building blocks of alternating naphthalenes and fluorenes. The resistance and current-voltage characteristics of ONI wires were measured as a function of molecular length, temperature, and electric field using conducting probe atomic force microscopy (CP-AFM). We have observed a transition in direct current (DC) transport from tunneling to hopping near 4 nm as previously established for oligophenyleneimine (OPI) wires. Furthermore, we have found that long ONI wires are less resistive than OPI wires. The single-wire conductivity of ONI wires is approximately 1.8 +/- 0.1 x 10(-4) S/cm, a factor of approximately 2 greater than that of OPI wires, and consistent with the lower transport activation energy ( approximately 0.58 eV versus 0.65 eV or 13 versus 15 kcal/mol). Quantum chemical calculations reveal that charge is preferentially localized on the fluorene subunits and that the molecules are substantially twisted. Overall, this work confirms that imine addition chemistry can be used to build molecular wires long enough to probe the hopping transport regime. The versatility of this chemistry, in combination with CP-AFM, opens up substantial opportunities to probe the physical organic chemistry of hopping conduction in long conjugated molecules.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1520-5126
pubmed:author
pubmed:issnType
Electronic
pubmed:day
31
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4358-68
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Transition from tunneling to hopping transport in long, conjugated oligo-imine wires connected to metals.
pubmed:affiliation
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.