Premium
Molecular motion in some radiolabelled dipeptides: a muon spin relaxation study
Author(s) -
Rhodes Christopher J.,
Dintinger Timothy C.,
Morris Harry,
Scott Christopher A.
Publication year - 2002
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1030
Subject(s) - muonium , chemistry , glycylglycine , muon spin spectroscopy , activation energy , muon , adduct , amide , radical , molecule , stereochemistry , benzene , medicinal chemistry , crystallography , computational chemistry , organic chemistry , glycine , biochemistry , physics , amino acid , particle physics , hydrogen
Activation parameters were determined for the dynamics of radicals formed by muonium addition to glycylglycine (GlyGly; H 3 N + CH 2 CONHCH 2 CO 2 − ) and the doubly protected alanylalanine derivative [Boc‐AlaAla‐Bz; Bu t OCONHCH(Me)CONHCH(Me)CO—O—CH 2 Ph]. GlyGly forms an adduct by muonium addition to the amide carbonyl group which isomerizes by flipping the muon between opposite sides of the molecule, requiring an activation energy of 20.4 kJ mol −1 . In Boc‐AlaAla‐Bz, muonium addition to the benzene ring of the benzyl (—CH 2 Ph) group occurs, exhibiting an activation energy of 9.4 kJ mol −1 , believed to be from torsion about the C—Ph bond. Copyright © 2002 John Wiley & Sons, Ltd.