Heteronuclear dipolar couplings, total spin coherence, and bilinear rotations in NMR spectroscopy

Technical Report · Fri Jul 01 00:00:00 EDT 1983

DOI:https://doi.org/10.2172/5667670· OSTI ID:5667670

Garbow, J. R.

In Chapter 1 a variety of different introductory topics are presented. The potential complexity of the nuclear magnetic resonsnace (NMR) spectra of molecules dissolved in liquid crystal solvents serves to motivate the development of multiple quantum (MQ) spectroscopy. The basics of MQ NMR are reviewed in Chapter 2. An experimental search procedure for the optimization of MQ pulse sequences is introduced. Chapter 3 discusses the application of MQ NMR techniques to the measurement of dipolar couplings in heteronuclear spin systems. The advantages of MQ methods in such systems are developed and experimental results for partially oriented (1-/sup 13/C) benzene are presented. Several pulse sequences are introduced which employ a two-step excitation of heteronuclear MQ coherence. A new multiple pulse method, involving the simultaneous irradiation of both rare and abundant spin species, is described. The problem of the broadening of MQ transitions due to magnetic field inhomogeneity is considered in Chapter 4. The method of total spin coherence transfer echo spectroscopy (TSCTES) is presented, with experimets on partially oriented acetaldehyde serving to demonstrate this new technique. TSCTES results in MQ spectra which are sensitive to all chemical shifts and spin-spin couplings and which are free of inhomogeneous broadening. In Chapter 5 the spectroscopy of spin systems of several protons and a /sup 13/C nucleus in the isotropic phase is discussed. The usefulness of the heteronuclear bilinear rotation as a calculational tool is illustrated. Compensated bilinear ..pi.. rotations, which are relatively insensitive to timing parameter missets, are presented. A new technique for homonuclear proton decoupling, Bilinear Rotation Decoupling, is described and its success in weakly coupled systems is demonstrated.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5667670
• Report Number(s): LBL-16119; ON: DE84001214
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETALDEHYDE
NMR SPECTRA
BENZENE
CARBON 13
NUCLEAR MAGNETIC RESONANCE
SPECTROSCOPY
LIQUID CRYSTALS
SPIN ECHO
ALDEHYDES
AROMATICS
CARBON ISOTOPES
CRYSTALS
EVEN-ODD NUCLEI
FLUIDS
HYDROCARBONS
ISOTOPES
LIGHT NUCLEI
LIQUIDS
MAGNETIC RESONANCE
NUCLEI
ORGANIC COMPOUNDS
RESONANCE
SPECTRA
STABLE ISOTOPES
400103* - Radiometric & Radiochemical Procedures- (-1987)