Riichiro Kusaka

Nuclear Magnetic Resonance Studies of Ammonium Halides. I. Proton Magnetic Resonance in Single Crystals of Ammonium Chloride and Ammonium Bromide

Line shapes of proton magnetic resonance absorption in single crystals of ammonium chloride and bromide were measured in temperature range from 90°K to room temperature. At liquid air temperature, broad lines with structures corresponding to rigid configuration of ammonium ions were observed for both crystals. These structures were analysed by solving the nuclear magnetic energy levels of ammonium ion containing four protons and one nitrogen nucleus, and also by estimating the width of each component line. Theoretical line shapes coincide well with experimental ones in the chloride, but the agreement is worse in the bromide. Some possible origins for the disagreement in the latter case are discussed. Line width at higher temperatures narrowed by rapid rotation of ammonium ions was measured for various orientations of the crystal. A slightly discontinuous change of the second moments of the line was observed at the order-disorder transition point in the bromide.

Nuclear Magnetic Resonance Experiment on the Single Crystals of K2HgCl4·H2O and K2SnCl4·H2O. II, The resonance absorption due to four proton system and the revised determination of their crystal structures

The energy levels and the transition probabilities are calculated for four proton interaction. The result of calculation is applied to the case of the single crystals of K 2 HgCl 4 ·H 2 O and K 2 SnCl 4 ·H 2 O. Ten absorption lines are expected from the theoretical calculation, of which each five form a group. Since in general cases the separations between the lines belonging to one of these groups are small compared to the separation between these groups as a whole, the expected resonance figure roughly coincides with the case of two proton resonance. But the shapes of resonance peaks have further fine structures. The observed fine structures were analysed by the theoretical consideration, and it is shown that the agreement between the theory and the experiment is satisfactory, if we take the distance of main protons to be 1.607 A and the distance between the proton-proton lines for adjacent water molecules which are parallel with each other to be 3.60 A in the case of Hg-salt and 1.62 A and 3.90 A respe...

The Electric Quadrupole Splitting of the Nuclear Magnetic Resonance Lines of Sodium in a Single Crystal of Na2S2O3·5H2O

Splitting of the nuclear magnetic resonance lines of sodium due to the nuclear electric quadrupole interaction was measured in a single crystal of sodium thiosulphate pentahydrate. Since each molecule contains two sodium nuclei which have different electric quadrupole interactions, and there are two groups of molecules with different orientations in a unit cell, twelve lines were observed in general. The experimental results were compared with the theoretical calculation of Bersohn and the values of e 2 q Q , η and the directions of the principal axes of the field gradient tensor were determined for each nucleus. The values of e 2 q Q and η are 2.26 Mc/sec and 0.334, and 0.830 Me/sec and 0.41 respectively for two nuclei in the molecule.

Nuclear Magnetic Resonance Experiment on the Single Crystals of K2HgCl4·H2O and K2SnCl4·H2O. Part I

Proton magnetic resonances of water molecules in the single crystals of K 2 HgCl 4 ·H 2 O and K 2 SnCl 4 H 2 O were observed, and the distance and the direction of proton-proton line in each of water molecules in the unit cell were determined. The absorption lines are generally composed of four component lines, of which the separation varies with the direction of the externally applied magnetic field. These results are fairly well explained with the Pakes formula for two-proton system and by the fact that there are two different p-p directions in these crystals. The p-p distance in a water molecule determined in this experiment is 1.607 A, and the angles between the a -axis and p-p lines which lie on the plane parallel to the c -plane are ±21.4° for Hg-salt, and 1.62 A and ±39.5° respectively for Sn-salt. Each component line has further fine structures when the external field is applied to some particular directions. This cannot be explained by the assumption of two-spin system only, but understood by in...

Nuclear Magnetic Double Resonance Experiment on Two Proton System

Nuclear magnetic double resonance studies were done on two proton system in K 2 HgCl 4 ·H 2 O single crystal. Applying a strong r.f. field with the frequency nearly equal to that of one line in the doublet of two proton resonance, the line shape of the other line of the doublet was measured for various values of the intensity and frequency of the strong r.f. field. Generally, the observed line shape shows further doublet structure, and the separation and relative intensities of this doubler depend upon the intensity and frequency of the strong r.f. field. Some calculations were made for the line structure of two proton system under the influence of a strong r.f. field. The experimental results agree qualitatively with the calculation, but there exist some descrepancies in the absolute magnitudes of the splitting of the induced doublet.