Importance of water content and motion in the one-dimensional conductorK2Pt(CN)4Cl0.3·nH2O

Abstract

The proton NMR has been examined as a function of temperature in ${\mathrm{K}}_2\mathrm{Pt}{\left(\mathrm{CN}\right)}_4{\mathrm{Cl}}_{0.3}·n{\mathrm{H}}_2\mathrm{O}$. Our results indicate a distribution of tumbling times for the water molecules. This is explained in terms of the interaction of the permanent electric dipole moment of the water with a distribution of electric fields in the crystal caused by a random occupation of the ${\mathrm{K}}^{+}$ and ${\mathrm{Cl}}^{-}$ sites. It is proposed that the importance of the waters of hydration to this class of materials arises from their electric dipole moments. In particular we feel that the ordering of these moments provides significant shielding of the platinum chains from the potentials generated by the random occupation of the ${\mathrm{K}}^{+}$ and ${\mathrm{Cl}}^{-}$ sites. This provides a natural explanation for the dependence of conductivity on water content.