RAMAN AND ZN-67 NMR-STUDIES OF THE STRUCTURE OF ZINC (II) SOLUTIONS IN CONCENTRATED AQUEOUS POTASSIUM HYDROXIDE

The structure of solutions of Zn**2** plus in aqueous potassium hydroxide was investigated by laser Raman and **6**7Zn NMR techniques; several discrepancies in prior Raman data were reconciled. In the present study, Raman results obtained for a wide range of Zn**2** plus and OH** minus concentrations gave evidence of only one highly symmetrical Zn**2** plus complex. Substitution of deuterium for protium showed that the Zn**2** plus is mainly coordinated by hydroxyl groups. From the chemical shifts and bandwidths observed in the **6**7ZN NMR spectra of some of these solutions, it is possible to deduce (i) that the dominant Zn**2** plus complex is tetrahedral Zn(OH)//4**2** minus , and (ii) that the Zn**2** plus /OH** minus complex may begin to polymerize into hydroxy bridged aggregates at high Zn**2** plus concentrations.