Hydrated perrhenates

Rh(N03)3 stock solution (10.37% Rhby wt.) - Engelhard Corp. Perrhenic Acid stock solution (52.091% Re by wt.) - Engelhard Corp. Zirconyl Nitrate, hydrate - Aldrich Chemical Co. 

Coordination mediated anion detection in an aqueous medium is challenging due to the accompanying unfavourable eneigetic requirements of dehydration and the low binding constants of anions, particularly to neutral anionophores. Monolayers of (7) in water, however, give reproducible cathodic shifts (15-20 mV) in the presence of perrhenate, a comparatively poorly hydrated anion. 

The commercial products PEGDE (Fluka, > 98 %), CTAB (Serva, 99 %), n-hexane (Merck,P.A), hydrazine hydrate (Fluka, > 99 %), sodium perrhenate (Alfa, 99,95 %), potassium tetrachloroplatinate (Alfa, 99,9 %) and hexachloroplatinic acid (Alfa,P.A) were used without further purification. 

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