Planar or Nonplanar: What Is the Structure of Urea in Aqueous Solution?
A combined quantum chemical statistical mechanical method has been used to study the solvation of urea in water, with emphasis on the structure of urea. The model system consists of three parts: a Hartree−Fock quantum chemical core, 99 water molecules described with a polarizable force−field, and a...
Saved in:
Published in | The journal of physical chemistry. B Vol. 111; no. 39; pp. 11511 - 11515 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
04.10.2007
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | A combined quantum chemical statistical mechanical method has been used to study the solvation of urea in water, with emphasis on the structure of urea. The model system consists of three parts: a Hartree−Fock quantum chemical core, 99 water molecules described with a polarizable force−field, and a dielectric continuum. A free-energy profile along the transition of urea from planar to a nonplanar structure is calculated. This mode in aqueous solution is found to be floppy. That is, the structure of urea in water is not well-defined because the planar to nonplanar transition requires an energy of the order of the thermal energy at room temperature. We discuss the implications of this finding for simulation studies of urea in polar environments like water and proteins. |
---|---|
Bibliography: | ark:/67375/TPS-HGBFMLTH-6 istex:D79D8D4B82F55CD1F634185278AE8CC33D21EE90 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1520-6106 1520-5207 1520-5207 |
DOI: | 10.1021/jp073579x |