Abstract
Proton magnetic resonances of water molecules in the single crystals of K2HgCl4H2O and K2SnCl4H2O 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 Pake’s 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 Å, 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 Å 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 introducing the assumption of four-spin system.
