ON ORIENTATIONS OF WATER MOLECULES IN ROCHELLE SALT - A PROTON MAGNETIC RESONANCE STUDY

The angular dependence of the NMR spectrum of single crystals of NaKC 4H4O6·4H2O has been studied in eight planes of rotation with a view to establishing the orientations and proton-proton separations of the water molecules. The proton-proton vectors corresponding to (H2O)7, (H2O)8, and (H2O)9 have been uniquely determined and the related H coordinates calculated, but the vector corresponding to (H2O) 10 has not been determined as accurately. The experimental results are found to agree well with a previous two-dimensional neutron-diffraction study and with a recent deuteron magnetic resonance study of this compound in its orthorhombic modification.