I. Magnetic resonance studies of paramagnetic solutions. II. Kinetics of the ferrous iron-oxygen reaction in acidic phosphate-pyrophosphate solutions I. Magnetic Resonance Studies in Paramagnetic Solutions. II. Kinetics of the Ferrous Iron-Oxygen Reaction in Acidic Phosphate-Pyrophosphate Solutions

Year: 1958

DOI: 10.7907/266P-TV05

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

The techniques of Nuclear Magnetic Resonance and Electron Paramagnetic Resonance have been used to study the interaction of electrons and nuclei in solution. Results of a study of the interaction between paramagnetic manganeous ions [...] and water molecules indicate that the abnormally large ratio of the proton relaxation times, [...], previously found in the system, can be essentially explained by an isotropic hyperfine interaction between the electrons and protons in the solution. When this interaction is destroyed by complexing the [...] with the hexadentate ligand, ethylenediaminetetraacetate [...], or with the tetradentate ligand, nitrilotriacetate [...], [...] is increased slightly and [...] is increased markedly, so that [...] = [...] and the ratio is unity as expected.

An isotropic hyperfine interaction is also found to exist in ferric fluoride solutions. The interaction between the electrons of the ferric ion and the fluoride nuclei produces characteristic resonance spectra for the different complexes in the system. From a study of the system, the existence in solution of the [...] complex is definitely established. A value for the dissociation constant of the complex is obtained and an upper limit is set for the rate of exchange of complexed and uncomplexed fluorides in the system. The amount of 2s - character of the [...] bond in the ferric fluoride complexes is also obtained.

The shifts, due to the magnetic susceptibility in the system are treated in Section IV. It is found that the shifts deviate from the values one would expect if the susceptibility in the system were isotropic. Both organic and inorganic systems are treated. The method used to measure these small shifts is also described.

Part II consists of a published article on the oxygenation of ferrous ion in acidic phosphate-pyrophosphate solutions.