Topological and group theoretical analysis in dynamic nuclear magnetic resonance spectroscopy
A method is developed for constructing NMR reaction graphs which give the NMR signal and intensity ratio patterns. This is done by generating the irreducible representations spanned by nuclei (whose NMR are of interest) with generating functions obtained from group character cycle indices (GCCI's). The method generates the symmetry species spanned by the nuclei in both the rigid and nonrigid groups without having to know the character of the representation spanned by nuclei. For nonrigid molecules which exhibit internal rotations the GCCI's can be obtained without having to know their character tables. We outline a double-coset technique to obtain the equivalence classes of nuclei and thus to construct NMR reaction graphs. Using this technique one can obtain the NMR signal and intensity ratio patterns. We introduce the concept of restricted character cycle indices (RCCI's) which generate the irreducible representations spanned by a given equivalence class of nuclei. This in turn enables the prediction of coalescence, splitting patterns, and intensity ratios of NMR signals in dynamic processes. Applications to spontaneous generation of chiral signals are outlined, where a nonrigid molecule which possesses no chiral signals suddenly possesses chiral signals (which can be resolved with chiral shift reagents) at lower temperatures.
- Research Organization:
- Univ. of California, Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6370804
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 86:24
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NUCLEAR MAGNETIC RESONANCE
GROUP THEORY
TOPOLOGICAL MAPPING
CHIRAL SYMMETRY
DIAGRAMS
DYNAMICS
QUANTUM MECHANICS
THEORETICAL DATA
DATA
INFORMATION
MAGNETIC RESONANCE
MAPPING
MATHEMATICS
MECHANICS
NUMERICAL DATA
RESONANCE
SYMMETRY
TRANSFORMATIONS
656000* - Condensed Matter Physics
400201 - Chemical & Physicochemical Properties