Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2006-8-23
pubmed:abstractText
Rotational barriers of methyl-sized molecular rotators are investigated theoretically using ab initio and empirical force field calculations in molecular models simulating various environmental conditions experienced by the molecular rotors. Calculations on neopentane surrounded by methyl groups suggest that the neopentane's methyl rotational potential energy barrier can be reduced by up to an order of magnitude by locating satellite functional groups around the rotator at a geometry that destabilizes the staggered conformation of the rotator through van der Waals repulsive interactions and reduces the staggered/eclipsed relative energy difference. Molecular mechanics and molecular dynamics calculations indicate that this barrier-reducing geometry can also be found in molecular rotators surface mounted on graphite surfaces or carbon nanotube models. In these models, molecular dynamics simulations show that the rotation of methyl-sized functional groups can be catalyzed by van der Waals interactions, thus making very rigid rotators become thermally activated at room temperature. These results are discussed in the context of design of nanostructures and use of methyl groups as markers for microenvironmental conditions.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Aug
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11088-93
pubmed:year
2006
pubmed:articleTitle
Van der waals interactions and decrease of the rotational barrier of methyl-sized rotators: a theoretical study.
pubmed:affiliation
School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. jerome@scs.uiuc.edu
pubmed:publicationType
Journal Article