Some double resonance and multiple quantum NMR studies in solids

Technical Report · Tue Aug 01 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6210652· OSTI ID:6210652

Wemmer, D E

The first section of this work presents the theory and experimental applications to analysis of molecular motion of chemical shielding lineshapes obtained with high resolution double resonance NMR techniques. Analysis of /sup 13/C powder lineshapes in hexamethylbenzene (HMB) and decamethylferrocene (DMFe) show that these molecules reorient in a jumping manner about the symmetry axis. Analysis of proton chemical shielding lineshapes of residual protons in heavy ice (D/sub 2/O) show that protons are exchanged among the tetrahedral positions of neighboring oxygen atoms, consistent with motion expected from defect migration. The second section describes the application of Fourier Transform Double Quantum NMR to measurement of chemical shielding of deuterium in powder samples. Studies of partially deuterated benzene and ferrocene give equal shielding anisotropies, ..delta..sigma = -6.5 ppM. Theoretical predictions and experimental measurements of dipolar couplings between deuterons using FTDQ NMR are presented. Crystals of BaClO/sub 3/.D/sub 2/O, ..cap alpha..,..beta.. d-2 HMB and ..cap alpha..,..beta..,..gamma.. d-3 HMB were studied, as were powders of d-2 HMB and anisic acid. The third section discusses general multiple quantum spectroscopy in dipolar coupled spin systems. Theoretical description is made for creation and detection of coherences between states without quantum number selection rules ..delta..m = +-1. Descriptions of techniques for partial selectivity of order in preparation and detection of multiple quantum coherences are made. The effects on selectivity and resolution of echo pulses during multiple quantum experiments are discussed. Experimental observation of coherences up to order 6 have been made in a sample of benzene dissolved in a liquid crystal. Experimental verifications of order selection and echo generation have been made.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6210652
• Report Number(s): LBL-8042
• Country of Publication: United States
• Language: English

Related Subjects

656000* -- Condensed Matter Physics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AROMATICS
BENZENE
CARBON 13
CARBON ISOTOPES
CRYSTALS
DOUBLE RESONANCE METHODS
EVEN-ODD NUCLEI
FLUIDS
FOURIER TRANSFORMATION
HYDROCARBONS
INTEGRAL TRANSFORMATIONS
ISOTOPES
LIGHT NUCLEI
LIQUID CRYSTALS
LIQUIDS
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
RESOLUTION
RESONANCE
STABLE ISOTOPES
TRANSFORMATIONS