Document Detail


On the use of isovalued surfaces to determine molecule shape and reaction pathways.
MedLine Citation:
PMID:  2072126     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Novel insights into local molecule structure and reactivity can be gained from viewing isovalued surfaces of the molecular electron density, electrostatic potential and molecular orbitals rendered as colored, 3-D objects. For example, drawing positive and negative electrostatic isopotential surfaces partitions the molecule into regions subject to nucleophilic or electrophilic attack. Similarly, coloring isodensity surfaces to indicate the magnitude of the gradient of the electron density maps the molecule surface into regions of high and low electronegativity. A basic understanding of reaction mechanisms can also come from viewing and manipulating isovalued surfaces. A theory of molecular interactions, based upon second-order perturbation theory, provides for the decomposition of the intermolecular interaction energy into steric, electrostatic and orbital interactions. Color figures illustrate the docking of reactant molecular densities, electrostatic potentials and orbitals on low-energy pathways. The figures are used to visualize the steric, electrostatic and orbital contributions to molecular interaction energy. The visualization not only identifies low-energy reaction pathways, but it frequently reveals local interactions which determine the magnitude of the total interaction energy. Similar insight is not easily obtained by simple evaluation of the total interaction energy. Approximate transition states, built from structures along low-energy approach pathways, are excellent starting points for transition state searches.
Authors:
G D Purvis
Related Documents :
15836376 - Core-shell photoabsorption and photoelectron spectra of gas-phase pentacene: experiment...
15945666 - Elimination of translational and rotational motions in nuclear orbital plus molecular o...
18600826 - Evaluation of electron population terms for 4p, 3p, and (2p): how do homo and lumo shri...
15783666 - Determination of the orbital moment and crystal-field splitting in latio3.
19812836 - Structural and electronic properties of gold microclusters: assessment of the localized...
8458426 - Interaction of carbonyl cyanide m-chlorophenylhydrazone with the photosystem ii accepto...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of computer-aided molecular design     Volume:  5     ISSN:  0920-654X     ISO Abbreviation:  J. Comput. Aided Mol. Des.     Publication Date:  1991 Feb 
Date Detail:
Created Date:  1991-08-19     Completed Date:  1991-08-19     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8710425     Medline TA:  J Comput Aided Mol Des     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  55-80     Citation Subset:  IM    
Affiliation:
CAChe Group, Tektronix Inc., Beaverton, OR 97077.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Chemistry, Physical*
Computer Graphics*
Models, Molecular*
Molecular Conformation*
Molecular Structure*
Physicochemical Phenomena
Structure-Activity Relationship

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The inclusion of electrostatic hydration energies in molecular mechanics calculations.
Next Document:  Normal fluctuation of physiologic cardiovascular variables during anesthesia and the phenomenon of "...