Nuclear Magnetic Resonance Experiment on the Single Crystal Of Lithium Sulfate Monohydrate, Li₂SO₄H₂O

Proton magnetic resonance absorption of water molecules in the single crystal of Li 2 SO 4 ·H 2 O was observed, and the length and directions of the proton–proton line (p–p) of the water of crystallization were determined. The results obtained are as follows: there are two kinds of orientations of the p–p line in the unit cell, which contains two molecules of Li 2 SO 4 ·H 2 O, and they are symmetrically disposed with respect to the a c -plane, the plane of mirror, making the angles ±51° to that plane. The angle between the projection of each p–p line on the a c -plane and the positive direction of a -axis is 94°, and the length of p–p line is 1.59 Å. From the results obtained and the crystal structure by X-ray analysis, the bond angle of H–O–H is expected to lie between 106°50' and 112°40', and presumably some value nearer to 112°40' may be taken to be favorable from the consideration of the bonding character. The single crystals were prepared by a slow evaporation method from an aqueous solution in a water bath at 80°C.