Linked Life Data

18376976

Source:http://linkedlifedata.com/resource/pubmed/id/18376976

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2008-4-1
pubmed:abstractText
The anionic and neutral complexes of glycine with water were studied at at the coupled cluster level of theory with single, double, and perturbative triple excitations. The most stable neutral complex has a relatively small dipole moment (1.74 D) and does not bind an electron. Other neutral complexes involve a polar conformer of canonical glycine and support dipole-bound anionic states. The most stable anion is characterized by an electron vertical detachment energy of 1576 cm(-1), in excellent agreement with the experimental result of 1573 cm(-1). The (Gly.H(2)O)(-) complex supports local minima, in which the zwitterionic glycine is stabilized by one water and one excess electron. They are, however, neither thermodynamically nor kinetically stable with respect to the dipole-bound states based on the canonical tautomers of glycine. The electron correlation contributions to excess electron binding energies are important, in particular, for nonzwitterionic complexes. Our results indicate that the condensation energies for Gly((0,-))+H(2)O-->(Gly.H(2)O)((0,-)) are larger than the adiabatic electron affinity of Gly.H(2)O. The above results imply that collisions of Gly(-) with H(2)O might effectively remove Gly(-) from the ion distribution. This might explain why formation of Gly(-) and (Gly.H(2)O)(-) is very sensitive to source conditions. We analyzed shifts in stretching mode frequencies that develop upon formation of intra- and intermolecular hydrogen bonds and an excess electron attachment. The position of the main peak and a vibrational structure in the photoelectron spectroscopy spectrum of (Gly.H(2)O)(-) are well reproduced by our theoretical results.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9606
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
125101
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Effect of excess electron and one water molecule on relative stability of the canonical and zwitterionic tautomers of glycine.
pubmed:affiliation
Department of Chemistry, University of Gda?sk, 80-952 Gda?sk, Poland.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't