Development of a Karplus-type relationship for sold-state deuterium nuclear magnetic resonance spectroscopy

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7291693

Jackisch, M A.C.

Zero-field high-resolution deuterium adiabatic demagnetization in the laboratory frame (ADLF) spectroscopy has been used to distinguish between two inequivalent deuterium positions in alpha-substituted arylacetic acids. High resolution spectra with linewidths of 1-2 kHz were observed and have been used successfully to document the inequivalent positions both by single and double transition spectra. Further, small applied fields, inducing Zeeman splitting, have proven the deuterons observed to be from the transition frequencies of two different deuterons. Individual spectra are shown for all compounds included in this study. The quadrupole coupling constants, e{sup 2}q{sub zz}Q/h, were calculated from spectral data. Torsion angle data were calculated from single crystal X-ray analysis. The Karplus equation, a method of examining three bond J coupling in solution NMR spectroscopy has been adapted for use in solid-state zero-field deuterium NMR spectroscopy for the H-C-C-X torsion angle where X is an heavy atom: e{sup 2}q{sub zz}Q/h = A {minus} B cos({theta}) {minus} C cos(2{theta}) {minus} D sin(2{phi}). The parameters, A, C, and D are derived from experimental data; B was obtained from molecular orbital calculations. The quadrupole coupling constants and torsion angles, {sup 2}H-C{sub alpha}-C{sub acid}OH({theta}) and C{sub ortho}-C{sub ring}-C{sub alpha}-C{sub acid}({phi}), were calculated from experimental data. Two and three dimensional graphs have been generated. From the three dimensional graphs, the torsion angles for an arylacetic acid without a crystal structure have been predicted based upon the results of ADLF spectroscopy and the Karplus-type relationship.

• Research Organization: Louisiana State Univ. and Agricultural and Mechanical Coll., Baton Rouge, LA (United States)
• OSTI ID: 7291693
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
COUPLING CONSTANTS
DATA
DEUTERIUM
EXPERIMENTAL DATA
HYDROGEN ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RESONANCE
SOLIDS
STABLE ISOTOPES