Multiple quantum nuclear magnetic resonance of solids: A cautionary note for data analysis and interpretation

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.465616· OSTI ID:6048204

Lacelle, S ^[1]; Hwang, S ^[2]; Gerstein, B C ^[3]

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1. Department de Chimie, Universite de Sherbrooke, Sherbrooke, Quebec J1K 2R1 (Canada)
2. Department of Chemistry and Ames Laboratory, USDOE, Iowa State University, Ames, Iowa 50011 (United States)
3. Ames Laboratory, USDOE Iowa State University, Ames, Iowa 50011 (United States)

The conventional method of data analysis and interpretation of time-resolved multiple quantum (MQ) nuclear magnetic resonance (NMR) spectra of solids is closely examined. Intensity profiles of experimental [sup 1]H MQ NMR spectra of polycrystalline adamantane and hexamethylbenzene serve to test the Gaussian statistical model approach. Consequences of this model are explored with a least-squares fitting procedure, transformation of data to yield linear plots, and a scaling analysis. Non-Gaussian behavior of the MQ NMR spectral intensity profiles, as a function of order of coherences, is demonstrated with all these methods of analysis. A heuristic argument, based on the multiplicative properties of dipolar coupling constants in the equation of motion of the density operator, leads to the prediction of exponentially decaying MQ NMR spectral intensity profiles. Scaling analysis and semilog plots of experimental time-resolved MQ NMR spectra of adamantane and hexamethylbenzene support this deduction. Dynamical scale invariance in the growth process of multiple spin coherences is revealed with this new approach. The validity of spin counting in solids with MQ NMR is discussed in light of the present results.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6048204
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 99:11; ISSN 0021-9606; ISSN JCPSA6
• Country of Publication: United States
• Language: English

Related Subjects

665100* -- Nuclear Techniques in Condensed Matter Physics -- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ADAMANTANE
ALKANES
ALKYL RADICALS
AMPLITUDES
AROMATICS
BENZENE
CRYSTALS
CYCLOALKANES
DATA ANALYSIS
FUNCTIONS
GAUSS FUNCTION
HYDROCARBONS
LEAST SQUARE FIT
MAGNETIC RESONANCE
MAXIMUM-LIKELIHOOD FIT
METHYL RADICALS
NUCLEAR MAGNETIC RESONANCE
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
POLYCRYSTALS
RADICALS
RESOLUTION
RESONANCE
SCALING LAWS
SOLIDS
TIME RESOLUTION
TIMING PROPERTIES
TRANSFORMATIONS