Influence of a Second Radiofrequency Field on High‐Resolution Nuclear Magnetic Resonance Spectra

A theoretical treatment of nuclear‐magnetic double‐irradiation experiments is given which is applicable to two groups of nuclei of arbitrary spin, either of different nuclear species or in a situation where the chemical shift is large in comparison with the spin‐coupling constant. A convention is introduced whereby the group which experiences the ``strong'' rf field H2 is given the symbol X, while the group to be investigated is represented by A. Particular attention is given to groups of spin ½ nuclei in AnXm type molecules where m, n≤3, and their spin‐decoupling behavior is presented in graphical form. Good correlations are observed with the experimental proton double‐resonance spectra of acetaldehyde, diethyl succinate, and 1,1,2 trichloroethane. When a single X transition is irradiated with a very weak H2 a splitting of the A spin‐multiplet lines into submultiplets is observed; at the same time an Overhauser‐type redistribution of intensities may occur in certain molecules. Intermediate strengths of H...

[1]  A. Abragam,et al.  OVERHAUSER EFFECT IN NONMETALS , 1955 .

[2]  R. Pound,et al.  High‐Resolution NMR Spectrometer with the Radio Frequency Controlled by the Magnetic Field , 1960 .

[3]  Norman F. Ramsey,et al.  Use of Rotating Coordinates in Magnetic Resonance Problems , 1954 .

[4]  J. Shoolery,et al.  EFFECTS OF PERTURBING RADIOFREQUENCY FIELDS ON NUCLEAR SPIN COUPLING , 1955 .

[5]  S. Yatsiv.  ROLE OF DOUBLE-QUANTUM TRANSITIONS IN MASERS , 1959 .

[6]  R. Freeman.  Spin decoupling in high resolution proton magnetic resonance , 1960 .

[7]  R. Kaiser.  Double Resonance Technique for the Elimination of Proton Spin‐Spin Splitting in High Resolution PMR Spectra , 1960 .

[8]  A. Clogston.  Susceptibility of the three-level maser , 1958 .

[9]  John D. Roberts.  An Introduction to the Analysis of Spin-Spin Splitting in High-Resolution Nuclear Magnetic Resonance Spectra , 1961 .

[10]  I. Solomon,et al.  Nuclear Magnetic Interactions in the HF Molecule , 1956 .

[11]  R. Pound.  Nuclear Electric Quadrupole Interactions in Crystals , 1950 .

[12]  R. Freeman,et al.  Determination of the relative signs of proton spin coupling constants by double irradiation , 1961 .

[13]  R. Freeman,et al.  The Effect of a Second Radiofrequency Field on High Resolution Proton Magnetic Resonance Spectra , 1962 .

[14]  Theory of Nuclear Level Density , 1954 .

[15]  P. L. Jain,et al.  MULTIPLE THERMAL RELAXATION TIMES AND NUCLEAR SPIN ENERGY TRANSFER IN LIQUIDS , 1956 .

[16]  F. Bloch.  Dynamical Theory of Nuclear Induction. II , 1956 .

[17]  E. Purcell,et al.  INTERACTIONS BETWEEN NUCLEAR SPINS IN MOLECULES , 1952 .

[18]  A. Javan.  Theory of a Three-Level Maser , 1957 .

[19]  J. Pople,et al.  High-resolution nuclear magnetic resonance , 1959 .

[20]  M. E. Rose.  Elementary Theory of Angular Momentum , 1957 .

[21]  E. R. Andrew,et al.  Nuclear Magnetic Resonance , 1955 .

[22]  R. Freeman.  The relative signs of N.M.R. spin coupling constants from double irradiation experiments , 1961 .

[23]  A. Overhauser.  STORED ENERGY MEASUREMENTS IN IRRADIATED COPPER , 1954 .

[24]  J. Baldeschwieler.  Quadrupole Relaxation Effects in Nuclear Magnetic Double Resonance , 1961 .

[25]  Norman F. Ramsey,et al.  Resonance Transitions Induced by Perturbations at Two or More Different Frequencies , 1955 .

[26]  W. A. Anderson.  Nuclear Magnetic Resonance Spectra of Some Hydrocarbons , 1956 .